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Chen J, Aido M, Roschger A, van Tol A, Checa S, Willie BM, Weinkamer R. Spatial variations in the osteocyte lacuno-canalicular network density and analysis of the connectomic parameters. PLoS One 2024; 19:e0303515. [PMID: 38743675 PMCID: PMC11093372 DOI: 10.1371/journal.pone.0303515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 04/05/2024] [Indexed: 05/16/2024] Open
Abstract
Osteocyte lacuno-canalicular network (LCN) is comprised of micrometre-sized pores and submicrometric wide channels in bone. Accumulating evidence suggests multiple functions of this network in material transportation, mechanobiological signalling, mineral homeostasis and bone remodelling. Combining rhodamine staining and confocal laser scanning microscopy, the longitudinal cross-sections of six mouse tibiae were imaged, and the connectome of the network was quantified with a focus on the spatial heterogeneities of network density, connectivity and length of canaliculi. In-vivo loading and double calcein labelling on these tibiae allowed differentiating the newly formed bone from the pre-existing regions. The canalicular density of the murine cortical bone varied between 0.174 and 0.243 μm/μm3, and therefore is three times larger than the corresponding value for human femoral midshaft osteons. The spatial heterogeneity of the network was found distinctly more pronounced across the cortex than along the cortex. We found that in regions with a dense network, the LCN conserves its largely tree-like character, but increases the density by including shorter canaliculi. The current study on healthy mice should serve as a motivating starting point to study the connectome of genetically modified mice, including models of bone diseases and of reduced mechanoresponse.
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Affiliation(s)
- Junning Chen
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
- Department of Engineering, Faculty of Environment, Science and Economy, University of Exeter, Exeter, United Kingdom
| | - Marta Aido
- Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Berlin-Brandenburg School for Regenerative Therapies (BSRT), Berlin, Germany
| | - Andreas Roschger
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
- Department of Chemistry and Physics of Materials, Paris-Lodron-University of Salzburg, Salzburg, Austria
| | - Alexander van Tol
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Sara Checa
- Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Bettina M. Willie
- Department of Pediatric Surgery, Research Centre, Shriners Hospital for Children-Canada, McGill University, Montreal, Canada
| | - Richard Weinkamer
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
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2
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Zambuto SG, Jain I, Theriault HS, Underhill GH, Harley BAC. Cell Chirality of Micropatterned Endometrial Microvascular Endothelial Cells. Adv Healthc Mater 2024; 13:e2303928. [PMID: 38291861 PMCID: PMC11076162 DOI: 10.1002/adhm.202303928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/14/2024] [Indexed: 02/01/2024]
Abstract
Chirality is an intrinsic cellular property that describes cell polarization biases along the left-right axis, apicobasal axis, or front-rear axes. Cell chirality plays a significant role in the arrangement of organs in the body as well as in the orientation of organelles, cytoskeletons, and cells. Vascular networks within the endometrium, the mucosal inner lining of the uterus, commonly display spiral architectures that rapidly form across the menstrual cycle. Herein, the role of endometrial-relevant extracellular matrix stiffness, composition, and soluble signals on endometrial endothelial cell chirality is systematically examined using a high-throughput microarray. Endometrial endothelial cells display marked patterns of chirality as individual cells and as cohorts in response to substrate stiffness and environmental cues. Vascular networks formed from endometrial endothelial cells also display shifts in chirality as a function of exogenous hormones. Changes in cellular-scale chirality correlate with changes in vascular network parameters, suggesting a critical role for cellular chirality in directing endometrial vessel network organization.
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Affiliation(s)
- Samantha G Zambuto
- Dept. of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Ishita Jain
- Dept. of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Hannah S Theriault
- Dept. of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Gregory H Underhill
- Dept. of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Brendan A C Harley
- Dept. Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
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3
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Wang J, Ishimoto T, Matsuzaka T, Matsugaki A, Ozasa R, Matsumoto T, Hayashi M, Kim HS, Nakano T. Adaptive enhancement of apatite crystal orientation and Young's modulus under elevated load in rat ulnar cortical bone. Bone 2024; 181:117024. [PMID: 38266952 DOI: 10.1016/j.bone.2024.117024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/02/2024] [Accepted: 01/19/2024] [Indexed: 01/26/2024]
Abstract
Functional adaptation refers to the active modification of bone structure according to the mechanical loads applied daily to maintain its mechanical integrity and adapt to the environment. Functional adaptation relates to bone mass, bone mineral density (BMD), and bone morphology (e.g., trabecular bone architecture). In this study, we discovered for the first time that another form of bone functional adaptation of a cortical bone involves a change in bone quality determined by the preferential orientation of apatite nano-crystallite, a key component of the bone. An in vivo rat ulnar axial loading model was adopted, to which a 3-15 N compressive load was applied, resulting in approximately 440-3200 μɛ of compression in the bone surface. In the loaded ulnae, the degree of preferential apatite c-axis orientation along the ulnar long axis increased in a dose-dependent manner up to 13 N, whereas the increase in BMD was not dose-dependent. The Young's modulus along the same direction was enhanced as a function of the degree of apatite orientation. This finding indicates that bone has a mechanism that modifies the directionality (anisotropy) of its microstructure, strengthening itself specifically in the loaded direction. BMD, a scalar quantity, does not allow for load-direction-specific strengthening. Functional adaptation through changes in apatite orientation is an excellent strategy for bones to efficiently change their strength in response to external loading, which is mostly anisotropic.
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Affiliation(s)
- Jun Wang
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan; Division of Material Science and Engineering, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, China.
| | - Takuya Ishimoto
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan; Aluminium Research Center, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan.
| | - Tadaaki Matsuzaka
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Aira Matsugaki
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Ryosuke Ozasa
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Takuya Matsumoto
- Department of Biomaterials, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1, Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
| | - Mikako Hayashi
- Department of Restorative Dentistry and Endodontology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Hyoung Seop Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, South Korea.
| | - Takayoshi Nakano
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Schurman CA, Kaya S, Dole N, Luna NMM, Castillo N, Potter R, Rose JP, Bons J, King CD, Burton JB, Schilling B, Melov S, Tang S, Schaible E, Alliston T. Aging impairs the osteocytic regulation of collagen integrity and bone quality. Bone Res 2024; 12:13. [PMID: 38409111 PMCID: PMC10897167 DOI: 10.1038/s41413-023-00303-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 10/31/2023] [Accepted: 11/13/2023] [Indexed: 02/28/2024] Open
Abstract
Poor bone quality is a major factor in skeletal fragility in elderly individuals. The molecular mechanisms that establish and maintain bone quality, independent of bone mass, are unknown but are thought to be primarily determined by osteocytes. We hypothesize that the age-related decline in bone quality results from the suppression of osteocyte perilacunar/canalicular remodeling (PLR), which maintains bone material properties. We examined bones from young and aged mice with osteocyte-intrinsic repression of TGFβ signaling (TβRIIocy-/-) that suppresses PLR. The control aged bone displayed decreased TGFβ signaling and PLR, but aging did not worsen the existing PLR suppression in male TβRIIocy-/- bone. This relationship impacted the behavior of collagen material at the nanoscale and tissue scale in macromechanical tests. The effects of age on bone mass, density, and mineral material behavior were independent of osteocytic TGFβ. We determined that the decline in bone quality with age arises from the loss of osteocyte function and the loss of TGFβ-dependent maintenance of collagen integrity.
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Affiliation(s)
- Charles A Schurman
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA, 94143, USA
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Serra Kaya
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
| | - Neha Dole
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
| | - Nadja M Maldonado Luna
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA, 94143, USA
| | - Natalia Castillo
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
| | - Ryan Potter
- Washington University in St Louis, Department of Orthopedics, St. Louis, MO, 63130, USA
| | - Jacob P Rose
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Joanna Bons
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | | | - Jordan B Burton
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | | | - Simon Melov
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Simon Tang
- Washington University in St Louis, Department of Orthopedics, St. Louis, MO, 63130, USA
| | - Eric Schaible
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA.
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA, 94143, USA.
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5
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Kumar R. Computer model of non-Newtonian canalicular fluid flow in lacunar-canalicular system of bone tissue. Comput Methods Biomech Biomed Engin 2024:1-15. [PMID: 38372236 DOI: 10.1080/10255842.2024.2317442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 02/03/2024] [Indexed: 02/20/2024]
Abstract
Brittle bone diseases are a global healthcare problem for orthopaedic clinicians, that reduces bone strength and promotes bone fracture risk. In vivo studies reported that loading-induced fluid flow through the lacunar-canalicular channel (LCS) of bone tissue inhibit such bone loss and encourages osteogenesis i.e. new bone formation. Canalicular fluid flow converts mechanical signals into biological signals and regulates bone reconstruction by releasing signalling molecules responsible for mechanotransduction. In-silico model mostly considers canalicular fluid is Newtonian, however, physiological canalicular fluid may be non-Newtonian in nature as it contains nutrients and supplements. Accordingly, this study attempts to develop a two-dimensional in-silico model to compute loading-induced non-Newtonian canalicular fluid flow in a complex LCS of bone tissue. Moreover, canalicular fluid is considered as a Jeffery fluid, that can easily be reduced to Newtonian fluid as a special case. The results show that physiological loading modulates the canalicular fluid flow, wall shear stress (WSS) and streamline in bone LCS. Fluid velocity and WSS increases with increase in non-dimensional frequency and non-Newtonian parameter (Jeffery fluid parameters) and reduce with change in permeability. The outcomes of this study may provide new insights in the role of mechanical loading-induced non-Newtonian canalicular fluid flow dynamics in bone LCS. The key findings of this study can be used to improve the understanding of osteocyte mechanobiology involved inside the bone tissue.
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Affiliation(s)
- Rakesh Kumar
- Department of Mechanical Engineering, Manipal University Jaipur, Jaipur-303007, Rajasthan, India
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6
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Bolger MW, Tekkey T, Kohn DH. Peripheral canalicular branching is decreased in streptozotocin-induced diabetes and correlates with decreased whole-bone ultimate load and perilacunar elastic work. JBMR Plus 2024; 8:ziad017. [PMID: 38505218 PMCID: PMC10945723 DOI: 10.1093/jbmrpl/ziad017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 12/01/2023] [Accepted: 12/06/2023] [Indexed: 03/21/2024] Open
Abstract
Osteocytes, the most abundant cell type in bone, play a crucial role in mechanosensation and signaling for bone formation and resorption. These cells reside within a complex lacuno-canalicular network (OLCN). Osteocyte signaling is reduced under diabetic conditions, and both type 1 and type 2 diabetes lead to reduced bone turnover, perturbed bone composition, and increased fracture risk. We hypothesized that this reduced bone turnover, and altered bone composition with diabetes is associated with reduced OLCN architecture and connectivity. This study aimed to elucidate: (1) the sequence of OLCN changes with diabetes related to bone turnover and (2) whether changes to the OLCN are associated with tissue composition and mechanical properties. Twelve- to fourteen-week-old male C57BL/6 mice were administered streptozotocin at 50 mg/kg for 5 consecutive days to induce hyperglycemia, sacrificed at baseline (BL), or after being diabetic for 3 (D3) and 7 (D7) wk with age-matched (C3, C7) controls (n = 10-12 per group). Mineralized femoral sections were infiltrated with rhodamine, imaged with confocal microscopy, then the OLCN morphology and topology were characterized and correlated against bone histomorphometry, as well as local and whole-bone mechanics and composition. D7 mice exhibited a lower number of peripheral branches relative to C7. The total number of canalicular intersections (nodes) was lower in D3 and D7 relative to BL (P < 0.05 for all), and a reduced bone formation rate (BFR) was observed at D7 vs C7. The number of nodes explained only 15% of BFR, but 45% of Ct.BV/TV, and 31% of ultimate load. The number of branches explained 30% and 22% of the elastic work at the perilacunar and intracortical region, respectively. Collectively, the reduction in OLCN architecture and association of OLCN measures with bone turnover, mechanics, and composition highlights the relevance of the osteocyte and the OLCN and a potential therapeutic target for treating diabetic skeletal fragility.
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Affiliation(s)
- Morgan W Bolger
- Department of Biomedical Engineering, College of Engineering, University of Michigan, Ann Arbor, MI 48109, United States
| | - Tara Tekkey
- Department of Chemistry, College of Literature, Science and the Arts, University of Michigan, Ann Arbor, MI 48109, United States
| | - David H Kohn
- Department of Biomedical Engineering, College of Engineering, University of Michigan, Ann Arbor, MI 48109, United States
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, United States
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7
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Vetter SD, Schurman CA, Alliston T, Slabaugh GG, Verbruggen SW. Deep learning models to map osteocyte networks can successfully distinguish between young and aged bone. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.20.572567. [PMID: 38187546 PMCID: PMC10769292 DOI: 10.1101/2023.12.20.572567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Osteocytes, the most abundant and mechanosensitive cells in bone tissue, play a pivotal role in bone homeostasis and mechano-responsiveness, orchestrating the intricate balance between bone formation and resorption under daily activity. Studying osteocyte connectivity and understanding their intricate arrangement within the lacunar canalicular network (LCN) is essential for unraveling bone physiology. This is particularly true as our bones age, which is associated with decreased integrity of the osteocyte network, disrupted mass transport, and lower sensitivity to the mechanical stimuli that allow the skeleton to adapt to changing demands. Much work has been carried out to investigate this relationship, often involving high resolution microscopy of discrete fragments of this network, alongside advanced computational modelling of individual cells. However, traditional methods of segmenting and measuring osteocyte connectomics are time-consuming and labour-intensive, often hindered by human subjectivity and limited throughput. In this study, we explore the application of deep learning and computer vision techniques to automate the segmentation and measurement of osteocyte connectomics, enabling more efficient and accurate analysis. We compare several state-of-the-art computer vision models (U-Nets and Vision Transformers) to successfully segment the LCN, finding that an Attention U-Net model can accurately segment and measure 81.8% of osteocytes and 42.1% of dendritic processes, when compared to manual labelling. While further development is required, we demonstrate that this degree of accuracy is already sufficient to distinguish between bones of young (2 month old) and aged (36 month old) mice, as well as capturing the degeneration induced by genetic modification of osteocytes. By harnessing the power of these advanced technologies, further developments can unravel the complexities of osteocyte networks in unprecedented detail, revolutionising our understanding of bone health and disease.
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Affiliation(s)
- Simon D. Vetter
- School of Electronic Engineering and Computer Science, Queen Mary University of London, UK
- Digital Environment Research Institute, Queen Mary University of London, UK
| | - Charles A. Schurman
- Department of Orthopaedic Surgery, University of California, San Francisco, CA 94143, USA
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA 94143, USA
- Buck Institute for Research on Aging, Novato, CA, USA
| | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California, San Francisco, CA 94143, USA
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA 94143, USA
| | - Gregory G. Slabaugh
- School of Electronic Engineering and Computer Science, Queen Mary University of London, UK
- Digital Environment Research Institute, Queen Mary University of London, UK
- Alan Turing Institute, British Library, 96 Euston Rd, London NW1 2DB, UK
| | - Stefaan W. Verbruggen
- Digital Environment Research Institute, Queen Mary University of London, UK
- Centre for Predictive in vitro Models, School of Engineering and Materials Science, Queen Mary University of London, UK
- INSIGNEO Institute for In Silico Medicine, University of Sheffield, UK
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8
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Huang C, Cheng Y, Zheng W, Bing RW, Zhang H, Komornicki I, Harris LM, Arany PR, Chakraborty S, Zhou Q, Xu W, Xia J. Dual-Scan Photoacoustic Tomography for the Imaging of Vascular Structure on Foot. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:1703-1713. [PMID: 37276111 PMCID: PMC10809222 DOI: 10.1109/tuffc.2023.3283139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Chronic leg ulcers are affecting approximately 6.5 million Americans, and they are associated with significant mortality, reduced quality of life, and high treatment costs. Since many chronic ulcers have underlying vascular insufficiency, accurate assessment of tissue perfusion is critical to treatment planning and monitoring. This study introduces a dual-scan photoacoustic (PA) tomography (PAT) system that can simultaneously image the dorsal and plantar sides of the foot to reduce imaging time. To account for the unique shape of the foot, the system employs height-adjustable and articulating baseball stages that can scan along the foot's contour. In vivo results from healthy volunteers demonstrate the system's ability to acquire clear images of foot vasculature, and results from patients indicate that the system can image patients with various ulcer conditions. We also investigated various PA features and examined their correlation with the foot condition. Our preliminary results indicate that vessel sharpness, occupancy, intensity, and density could all be used to assess tissue perfusion. This research demonstrated the potential of PAT for routine clinical tissue perfusion assessment.
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Sefa S, Espiritu J, Ćwieka H, Greving I, Flenner S, Will O, Beuer S, Wieland DF, Willumeit-Römer R, Zeller-Plumhoff B. Multiscale morphological analysis of bone microarchitecture around Mg-10Gd implants. Bioact Mater 2023; 30:154-168. [PMID: 37575877 PMCID: PMC10412723 DOI: 10.1016/j.bioactmat.2023.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 07/07/2023] [Accepted: 07/20/2023] [Indexed: 08/15/2023] Open
Abstract
The utilization of biodegradable magnesium (Mg)-based implants for restoration of bone function following trauma represents a transformative approach in orthopaedic application. One such alloy, magnesium-10 weight percent gadolinium (Mg-10Gd), has been specifically developed to address the rapid degradation of Mg while enhancing its mechanical properties to promote bone healing. Previous studies have demonstrated that Mg-10Gd exhibits favorable osseointegration; however, it exhibits distinct ultrastructural adaptation in comparison to conventional implants like titanium (Ti). A crucial aspect that remains unexplored is the impact of Mg-10Gd degradation on the bone microarchitecture. To address this, we employed hierarchical three-dimensional imaging using synchrotron radiation in conjunction with image-based finite element modelling. By using the methods outlined, the vascular porosity, lacunar porosity and the lacunar-canaliculi network (LCN) morphology of bone around Mg-10Gd in comparison to Ti in a rat model from 4 weeks to 20 weeks post-implantation was investigated. Our investigation revealed that within our observation period, the degradation of Mg-10Gd implants was associated with significantly lower (p < 0.05) lacunar density in the surrounding bone, compared to Ti. Remarkably, the LCN morphology and the fluid flow analysis did not significantly differ for both implant types. In summary, a more pronounced lower lacunae distribution rather than their morphological changes was detected in the surrounding bone upon the degradation of Mg-10Gd implants. This implies potential disparities in bone remodelling rates when compared to Ti implants. Our findings shed light on the intricate relationship between Mg-10Gd degradation and bone microarchitecture, contributing to a deeper understanding of the implications for successful osseointegration.
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Affiliation(s)
- Sandra Sefa
- Institute of Metallic Biomaterials, Helmholtz Zentrum Hereon, Geesthacht, Germany
| | | | - Hanna Ćwieka
- Institute of Metallic Biomaterials, Helmholtz Zentrum Hereon, Geesthacht, Germany
| | - Imke Greving
- Institute of Materials Physics, Helmholtz Zentrum Hereon, Geesthacht, Germany
| | - Silja Flenner
- Institute of Materials Physics, Helmholtz Zentrum Hereon, Geesthacht, Germany
| | - Olga Will
- Molecular Imaging North Competence Center, Kiel University, Kiel, Germany
| | - Susanne Beuer
- Fraunhofer Institut für Integrierte Systeme und Bauelementetechnologie (IISB), Erlangen, Germany
| | - D.C Florian Wieland
- Institute of Metallic Biomaterials, Helmholtz Zentrum Hereon, Geesthacht, Germany
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Müller H, Deffur C, Schmideder S, Barthel L, Friedrich T, Mirlach L, Hammel JU, Meyer V, Briesen H. Synchrotron radiation-based microcomputed tomography for three-dimensional growth analysis of Aspergillus niger pellets. Biotechnol Bioeng 2023; 120:3244-3260. [PMID: 37475650 DOI: 10.1002/bit.28506] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/05/2023] [Accepted: 07/11/2023] [Indexed: 07/22/2023]
Abstract
Filamentous fungi produce a wide range of relevant biotechnological compounds. The close relationship between fungal morphology and productivity has led to a variety of analytical methods to quantify their macromorphology. Nevertheless, only a µ-computed tomography (µ-CT) based method allows a detailed analysis of the 3D micromorphology of fungal pellets. However, the low sample throughput of a laboratory µ-CT limits the tracking of the micromorphological evolution of a statistically representative number of submerged cultivated fungal pellets over time. To meet this challenge, we applied synchrotron radiation-based X-ray microtomography at the Deutsches Elektronen-Synchrotron [German Electron Synchrotron Research Center], resulting in 19,940 3D analyzed individual fungal pellets that were obtained from 26 sampling points during a 48 h Aspergillus niger submerged batch cultivation. For each of the pellets, we were able to determine micromorphological properties such as number and density of spores, tips, branching points, and hyphae. The computed data allowed us to monitor the growth of submerged cultivated fungal pellets in highly resolved 3D for the first time. The generated morphological database from synchrotron measurements can be used to understand, describe, and model the growth of filamentous fungal cultivations.
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Affiliation(s)
- Henri Müller
- School of Life Sciences Weihenstephan, Chair of Process Systems Engineering, Technical University of Munich, Freising, Germany
| | - Charlotte Deffur
- School of Life Sciences Weihenstephan, Chair of Process Systems Engineering, Technical University of Munich, Freising, Germany
| | - Stefan Schmideder
- School of Life Sciences Weihenstephan, Chair of Process Systems Engineering, Technical University of Munich, Freising, Germany
| | - Lars Barthel
- Chair of Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Tiaan Friedrich
- School of Life Sciences Weihenstephan, Chair of Process Systems Engineering, Technical University of Munich, Freising, Germany
| | - Lukas Mirlach
- School of Life Sciences Weihenstephan, Chair of Process Systems Engineering, Technical University of Munich, Freising, Germany
| | - Jörg U Hammel
- Helmholtz-Zentrum hereon, Institute of Materials Physics, Geesthacht, Germany
| | - Vera Meyer
- Chair of Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Heiko Briesen
- School of Life Sciences Weihenstephan, Chair of Process Systems Engineering, Technical University of Munich, Freising, Germany
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11
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Zambuto SG, Jain I, Theriault HS, Underhill GH, Harley BAC. Cell Chirality of Micropatterned Endometrial Microvascular Endothelial Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.20.563368. [PMID: 37961315 PMCID: PMC10634711 DOI: 10.1101/2023.10.20.563368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Chirality is an intrinsic cellular property that describes cell polarization biases along the left-right axis, apicobasal axis, or front-rear axes. Cell chirality plays a significant role in the arrangement of organs in the body as well as the orientation of organelles, cytoskeletons, and cells. Vascular networks within the endometrium, the mucosal inner lining of the uterus, commonly display spiral architectures that rapidly form across the menstrual cycle. Herein, we systematically examine the role of endometrial-relevant extracellular matrix stiffness, composition, and soluble signals on endometrial endothelial cell chirality using a high-throughput microarray. Endometrial endothelial cells display marked patterns of chirality as individual cells and as cohorts in response to substrate stiffness and environmental cues. Vascular networks formed from endometrial endothelial cells also display shifts in chirality as a function of exogenous hormones. Changes in cellular-scale chirality correlate with changes in vascular network parameters, suggesting a critical role for cellular chirality in directing endometrial vessel network organization.
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12
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He MC, Tian JQ, He XM, Yang P, Lin TY, Zhang QW, He W, Wei QS. Mechanical properties of trabeculae and osteocyte morphology change significantly in different areas of the necrotic femoral head. Front Cell Dev Biol 2023; 11:1250070. [PMID: 37822871 PMCID: PMC10562544 DOI: 10.3389/fcell.2023.1250070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 09/12/2023] [Indexed: 10/13/2023] Open
Abstract
Background: Osteonecrosis of the femoral head is a complex hip ailment. The precise changes in bone tissue during the disease's onset remain unclear. It is vital to assess both the quantity and quality of the trabecular state in a necrotic femoral head. Aim: This study aims to identify and compare the ultrastructural changes in osteocyte morphology and nanomechanical characteristics within various regions of necrotic femoral heads. Methods: Between December 2016 and May 2023, we gathered ten necrotic femoral heads from patients and five femoral heads from cadavers. The samples from the necrotic femoral heads were categorized into three areas: necrotic, sclerotic, and normal. Our assessment methods encompassed hematoxylin and eosin staining, sclerostin (SOST) immunohistochemistry, micro-computed tomography, nanoindentation, and acid-etched scanning electron microscopy. These techniques enabled us to examine the SOST expression, trabecular microstructure, micromechanical properties of trabeculae, and modifications in osteocyte morphology at the ultrastructural level. Results: The protein level of SOST was found to be lower in the sclerotic area. In the necrotic area, decreased values of bone volume fraction, trabecular thickness, and trabecular number and an increased value of trabecular separation were found. Conversely, in the sclerotic area, higher mean values of bone volume fraction, trabecular number, and trabecular thickness and lower trabecular separation indicated significant changes in the structural characteristics of trabeculae. Compared with the healthy area, the elastic modulus and hardness in the sclerotic area were significantly higher than those in the necrotic, normal, and control areas, while those in necrotic areas were significantly lower than those in the healthy area. The number of osteocytes tended to increase in the sclerotic area with more canalicular cells compared to the healthy area and control group. Conclusion: These results imply that the stress distribution within the sclerotic area could potentially lead to enhanced trabecular quality and quantity. This effect is also reflected in the increased count of osteocytes and their canaliculars. It is plausible that the sclerotic trabecular bone plays a pivotal role in the repair of necrotic femoral heads.
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Affiliation(s)
- Min-Cong He
- Guangdong Research Institute for Orthopedics and Traumatology of Chinese Medicine, The Third Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jia-Qing Tian
- The Third Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xiao-Ming He
- Guangdong Research Institute for Orthopedics and Traumatology of Chinese Medicine, The Third Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Peng Yang
- Guangdong Research Institute for Orthopedics and Traumatology of Chinese Medicine, The Third Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Tian-Ye Lin
- Guangdong Research Institute for Orthopedics and Traumatology of Chinese Medicine, The Third Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Qing-Wen Zhang
- Guangdong Research Institute for Orthopedics and Traumatology of Chinese Medicine, The Third Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Wei He
- Guangdong Research Institute for Orthopedics and Traumatology of Chinese Medicine, The Third Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Qiu-Shi Wei
- The Third Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China
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13
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Liu Z, Niu Y, Fu Z, Dean M, Fu Z, Hu Y, Zou Z. 3D relationship between hierarchical canal network and gradient mineralization of shark tooth osteodentin. Acta Biomater 2023; 168:185-197. [PMID: 37451657 DOI: 10.1016/j.actbio.2023.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 06/25/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
Osteodentin is a dominant mineralized collagenous tissue in the teeth of many fishes, with structural and histological characteristics resembling those of bone. Osteodentin, like bone, comprises osteons as basic structural building blocks, however, it lacks the osteocytes and the lacuno-canalicular network (LCN), which are known to play critical roles in controlling the mineralization of the collagenous matrix in bone. Although numerous vascular canals exist in osteodentin, their role in tooth maturation and the matrix mineralization process remain poorly understood. Here, high resolution micro-computed tomography (micro-CT) and focused ion beam-scanning electron microscopy (FIB-SEM) were used to obtain 3D structural information of osteodentin in shark teeth at multiple scales. We observed a complex 3D network of primary canals with a diameter ranging from ∼10 µm to ∼120 µm, where the canals are surrounded by osteon-like concentric layers of lamellae, with 'interosteonal' tissue intervening between neighboring osteons. In addition, numerous hierarchically branched secondary canals extended radially from the primary canals into the interosteonal tissue, decreasing in diameter from ∼10 µm to hundreds of nanometers. Interestingly, the mineralization degree increases from the periphery of primary canals into the interosteonal tissue, suggesting that mineralization begins in the interosteonal tissue. Correspondingly, the hardness and elastic modulus of the interosteonal tissue are higher than those of the osteonal tissue. These results demonstrate that the 3D hierarchical canal network is positioned to play a critical role in controlling the gradient mineralization of osteodentin, also providing valuable insight into the formation of mineralized collagenous tissue without osteocytes and LCN. STATEMENT OF SIGNIFICANCE: Bone is a composite material with versatile mechanical properties. Osteocytes and their lacuno-canalicular network (LCN) are known to play critical roles during formation of human bone. However, the bone and osteodentin of many fishes, although lacking osteocytes and LCN, exhibit similar osteon-like structure and mechanical functions. Here, using various high resolution 3D characterization techniques, we reveal that the 3D network of primary canals and numerous hierarchically branched secondary canals correlate with the mineralization gradient and micromechanical properties of osteonal and interosteonal tissues of shark tooth osteodentin. This work significantly improves our understanding of the construction of bone-like mineralized tissue without osteocytes and LCN, and provides inspirations for the fabrication of functional materials with hierarchical structure.
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Affiliation(s)
- Zhuanfei Liu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
| | - Yunya Niu
- State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China
| | - Zeyao Fu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
| | - Mason Dean
- Department of Infectious Diseases & Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong, China
| | - Zhengyi Fu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
| | - Yongming Hu
- School of Microelectronics, Hubei University, Wuhan 430062, Hubei, China..
| | - Zhaoyong Zou
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.; Hubei Longzhong Laboratory, Wuhan University of Technology Xiangyang Demonstration Zone, Xiangyang 441000, China.
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14
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Wüster J, Hesse B, Rothweiler R, Bortel E, Gross C, Bakhtiyari S, King A, Boller E, Gerber J, Rendenbach C, Fretwurst T, Preissner S, Heiland M, Nelson K, Nahles S. Comparison of the 3D-microstructure of human alveolar and fibula bone in microvascular autologous bone transplantation: a synchrotron radiation μ-CT study. Front Bioeng Biotechnol 2023; 11:1169385. [PMID: 37691907 PMCID: PMC10486015 DOI: 10.3389/fbioe.2023.1169385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 08/01/2023] [Indexed: 09/12/2023] Open
Abstract
Introduction: Autologous bone transplantation is successfully used in reconstructive surgery of large/critical-sized bone defects, whereby the microvascular free fibula flap is still regarded as the gold standard for the reconstruction of such defects in the head and neck region. Here, we report the morphological and lacunar properties of patient-paired bone samples from eight patients from the jaw (AB; recipient site) and the fibula (FB; donor site) on the micron length-scale using Synchrotron µ-CT. Insights into differences and similarities between these bone structures could offer a better understanding of the underlying mechanism for successful surgical outcomes and might clear the path for optimized, nature-inspired bone scaffold designs. Methods: Spatial vessel-pore arrangements, bone morphology, fluid-simulation derived permeability tensor, osteocyte lacunar density, and lacunar morphology are compared. Results: The orientation of the vessel system indicates a homogenous vessel orientation for AB and FB. The average mineral distance (50%) to the closest vessel boundary is higher in AB than in FB (the mean is 96 μm for AB vs. 76 μm for FB; p = 0.021). Average osteocyte lacunar density is found to be higher in AB than in FB (mean 22,874 mm3 vs. 19,376 mm3 for FB; p = 0.038), which might compensate for the high distance from the mineral to the nearest vessel. No significant differences in lacunar volume are found between paired AB and FB. Discussion: A comparable vessel network and similar distribution of vessel porosity between AB and FB may allow the FB graft to exhibit a high regeneration potential when connected to AB, and this might correlate with a high osteoinductive and osteoconductive potential of FB when connected to AB. Since widely used and potent synthetic bone grafts exist, new insight into the bone structure of well-established autologous bone grafts, such as the free fibula flap, could help to improve the performance of such materials and therefore the design of 3D scaffolds.
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Affiliation(s)
- Jonas Wüster
- Department of Oral and Maxillofacial Surgery, Berlin Institute of Health, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Bernhard Hesse
- Xploraytion GmbH, Berlin, Germany
- European Synchrotron Radiation Facility, Grenoble, France
| | - Rene Rothweiler
- Department of Oral- and Craniomaxillofacial Surgery, Faculty of Medicine, Medical Center, University of Freiburg, Freiburg, Germany
| | | | - Christian Gross
- Department of Oral- and Craniomaxillofacial Surgery, Faculty of Medicine, Medical Center, University of Freiburg, Freiburg, Germany
| | | | | | - Elodie Boller
- European Synchrotron Radiation Facility, Grenoble, France
| | | | - Carsten Rendenbach
- Department of Oral and Maxillofacial Surgery, Berlin Institute of Health, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Tobias Fretwurst
- Department of Oral- and Craniomaxillofacial Surgery, Faculty of Medicine, Medical Center, University of Freiburg, Freiburg, Germany
| | - Saskia Preissner
- Department of Oral and Maxillofacial Surgery, Berlin Institute of Health, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Max Heiland
- Department of Oral and Maxillofacial Surgery, Berlin Institute of Health, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Katja Nelson
- Department of Oral- and Craniomaxillofacial Surgery, Faculty of Medicine, Medical Center, University of Freiburg, Freiburg, Germany
| | - Susanne Nahles
- Department of Oral and Maxillofacial Surgery, Berlin Institute of Health, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
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15
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Fischer SC, Bassel GW, Kollmannsberger P. Tissues as networks of cells: towards generative rules of complex organ development. J R Soc Interface 2023; 20:20230115. [PMID: 37491909 PMCID: PMC10369035 DOI: 10.1098/rsif.2023.0115] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 07/05/2023] [Indexed: 07/27/2023] Open
Abstract
Network analysis is a well-known and powerful tool in molecular biology. More recently, it has been introduced in developmental biology. Tissues can be readily translated into spatial networks such that cells are represented by nodes and intercellular connections by edges. This discretization of cellular organization enables mathematical approaches rooted in network science to be applied towards the understanding of tissue structure and function. Here, we describe how such tissue abstractions can enable the principles that underpin tissue formation and function to be uncovered. We provide an introduction into biologically relevant network measures, then present an overview of different areas of developmental biology where these approaches have been applied. We then summarize the general developmental rules underpinning tissue topology generation. Finally, we discuss how generative models can help to link the developmental rule back to the tissue topologies. Our collection of results points at general mechanisms as to how local developmental rules can give rise to observed topological properties in multicellular systems.
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Affiliation(s)
- Sabine C. Fischer
- Center for Computational and Theoretical Biology, Faculty of Biology, University of Würzburg, Würzburg, Germany
| | - George W. Bassel
- School of Life Sciences, The University of Warwick, Coventry, UK
| | - Philip Kollmannsberger
- Biomedical Physics, Department of Physics, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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16
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Xia Y, Liu J, Kancharla R, Li J, Hatamlee SM, Ren G, Semeykina V, Hamed A, Kane JJ. Insights into the 3D permeable pore structure within novel monodisperse mesoporous silica nanoparticles by cryogenic electron tomography. NANOSCALE ADVANCES 2023; 5:2879-2886. [PMID: 37260494 PMCID: PMC10228490 DOI: 10.1039/d3na00145h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 04/14/2023] [Indexed: 06/02/2023]
Abstract
Sintered agglomerate of synthetic mesoporous silica nanoparticles (MSNs) is an architected geomaterial that provides confinement-mediated flow and transport properties of fluids needed for environmental research such as geological subsurface energy storage or carbon capture. The design of those properties can be guided by numerical simulations but is hindered by the lack of method to characterize the permeable pores within MSNs due to pore size. This work uses the advances of an Individual Particle cryogenic transmission Electron Tomography (IPET) technique to obtain detailed 3D morphology of monodispersed MSNs with diameters below 50 nm. The 3D reconstructed density-maps show the diameters of those MSNs vary from 35-46 nm, containing connected intraparticle pores in diameter of 2-20 nm with a mean of 9.2 ± 3 nm, which is comparable to the mean interparticle pore diameters in sintered agglomerate. The characterization of the pore shape and dimensions provides key information for estimating the flow and transport properties of fluids within the sintered agglomerate of those MSNs and for modeling the atomic MSN structures needed for pore-fluid simulations.
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Affiliation(s)
- Yidong Xia
- Energy and Environment Science & Technology, Idaho National Laboratory Idaho Falls 83415 ID USA +01 208 526 7490
| | - Jianfang Liu
- Molecular Foundry, Lawrence Berkeley National Laboratory Berkeley 94720 CA USA
| | - Rahul Kancharla
- Materials & Fuels Complex, Idaho National Laboratory Idaho Falls 83415 ID USA
| | - Jiaoyan Li
- Department of Mechanical and Aerospace Engineering, University at Buffalo Buffalo 14260 NY USA
| | - Seyed M Hatamlee
- Department of Mechanical and Aerospace Engineering, University at Buffalo Buffalo 14260 NY USA
| | - Gang Ren
- Molecular Foundry, Lawrence Berkeley National Laboratory Berkeley 94720 CA USA
| | | | - Ahmed Hamed
- Energy and Environment Science & Technology, Idaho National Laboratory Idaho Falls 83415 ID USA +01 208 526 7490
| | - Joshua J Kane
- Materials & Fuels Complex, Idaho National Laboratory Idaho Falls 83415 ID USA
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17
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Liu X, Li J, Luan K. Determination of intramedullary nail based on centerline adaptive registration. Front Bioeng Biotechnol 2023; 11:1115473. [PMID: 37064247 PMCID: PMC10102502 DOI: 10.3389/fbioe.2023.1115473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 03/20/2023] [Indexed: 04/03/2023] Open
Abstract
Objective: Internal fixation with intramedullary nails is a gold standard for the treatment of femoral shaft fractures. However, both the mismatch between intramedullary nails and the medullary cavity and inaccurate positioning of entry points will lead to deformation of intramedullary nails after implantation. The study aimed to determine a suitable intramedullary nail with an optimal entry point for a specific patient based on centerline adaptive registration.Method: A homotopic thinning algorithm is employed to extract centerlines of the femoral medullary cavity and the intramedullary nail. The two centerlines are registered to obtain a transformation. The medullary cavity and the intramedullary nail are registered based on the transformation. Next, a plane projection method is employed to calculate the surface points of the intramedullary nail laid outside the medullary cavity. According to the distribution of compenetration points, an iterative adaptive registration strategy is designed to decide an optimal position of the intramedullary nail in medullary cavity. The isthmus centerline is extended to the femur surface, where the entry point of the intramedullary nail is located. The suitability of an intramedullary nail for a specific patient was calculated by measuring the geometric quantities reflecting the interference between the femur and nail, and the suitability values of all nails are compared and the most suitable one is determined.Results: The growth experiment indicated that the bone to nail alignment is indeed affected by the extension of the isthmus centerline, including the extension direction and velocity. The geometrical experiment showed that this method could find the best registration position of intramedullary nails and select the optimal intramedullary nail for a specific patient. In the model experiments, the determined intramedullary nail could be successfully placed into the medullary cavity through the optimal entry point. A pre-screening tool to determine nails which can be successfully used has been given. In addition, the distal hole was accurately located within 14.28 s.Conclusion: These results suggest that the proposed method can select a suitable intramedullary nail with an optimal entry point. The position of the intramedullary nail can be determined in the medullary cavity, while deformation is avoided. The proposed method can determine the largest diameter intramedullary nail with as little damage to the intramedullary tissue as possible. The proposed method provides preparation aid for internal fixation with intramedullary nails guided by navigation systems or extracorporeal aimers.
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18
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Curvature-based force estimation for an elastic tube. ROBOTICA 2023. [DOI: 10.1017/s0263574723000115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Abstract
Contact force is one of the most significant feedback for robots to achieve accurate control and safe interaction with environment. For continuum robots, it is possible to estimate the contact force based on the feedback of robot shapes, which can address the difficulty of mounting dedicated force sensors on the continuum robot body with strict dimension constraints. In this paper, we use local curvatures to estimate the magnitude and location of single or multiple contact forces based on Cosserat rod theory. We validate the proposed method in a thin elastic tube and calculate the curvatures via Fiber Bragg Grating (FBG) sensors or image feedback. For the curvature feedback obtained from multicore FBG sensors, the overall force magnitude estimation error is
$0.062 \pm 0.068$
N and the overall location estimation error is
$3.51 \pm 2.60$
mm. For the curvature feedback obtained from image, the overall force magnitude estimation error is
$0.049 \pm 0.048$
N and the overall location estimation error is
$2.75 \pm 1.71$
mm. The results demonstrate that the curvature-based force estimation method is able to accurately estimate the contact force.
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19
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Blouin S, Misof BM, Mähr M, Fratzl-Zelman N, Roschger P, Lueger S, Messmer P, Keplinger P, Rauch F, Glorieux FH, Berzlanovich A, Gruber GM, Brugger PC, Shane E, Recker RR, Zwerina J, Hartmann MA. Osteocyte lacunae in transiliac bone biopsy samples across life span. Acta Biomater 2023; 157:275-287. [PMID: 36549635 DOI: 10.1016/j.actbio.2022.11.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022]
Abstract
Osteocytes act as bone mechanosensors, regulators of osteoblast/osteoclast activity and mineral homeostasis, however, knowledge about their functional/morphological changes throughout life is limited. We used quantitative backscattered electron imaging (qBEI) to investigate osteocyte lacunae sections (OLS) as a 2D-surrogate characterizing the osteocytes. OLS characteristics, the density of mineralized osteocyte lacunae (i.e., micropetrotic osteocytes, md.OLS-Density in nb/mm2) and the average degree of mineralization (CaMean in weight% calcium) of cortex and spongiosa were analyzed in transiliac biopsy samples from healthy individuals under 30 (n=59) and over 30 years (n=50) (i.e., before and after the age of peak bone mass, respectively). We found several differences in OLS-characteristics: 1). Inter-individually between the age groups: OLS-Density and OLS-Porosity were reduced by about 20% in older individuals in spongiosa and in cortex versus younger probands (both, p < 0.001). 2). Intra-individually between bone compartments: OLS-Density was higher in the cortex, +18.4%, p < 0.001 for younger and +7.6%, p < 0.05 for older individuals. Strikingly, the most frequent OLS nearest-neighbor distance was about 30 µm in both age groups and at both bone sites revealing a preferential organization of osteocytes in clusters. OLS-Density was negatively correlated with CaMean in both spongiosa and cortex (both, p < 0.001). Few mineralized OLS were found in young individuals along with an increase of md.OLS-Density with age. In summary, this transiliac bone sample analysis of 200000 OLS from 109 healthy individuals throughout lifespan reveals several age-related differences in OLS characteristics. Moreover, our study provides reference data from healthy individuals for different ages to be used for diagnosis of bone abnormalities in diseases. STATEMENT OF SIGNIFICANCE: Osteocytes are bone cells embedded in lacunae within the mineralized bone matrix and have a key role in the bone metabolism and the mineral homeostasis. Not easily accessible, we used quantitative backscattered electron imaging to determine precisely number and shape descriptors of the osteocyte lacunae in 2D. We analyzed transiliac biopsy samples from 109 individuals with age distributed from 2 to 95 years. Compact cortical bone showed constantly higher lacunar density than cancellous bone but the lacunar density in both bone tissue decreased with age before the peak bone mass age at 30 years and stabilized or even increased after this age. This extensive study provides osteocyte lacunae reference data from healthy individuals usable for bone pathology diagnosis.
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Affiliation(s)
- Stéphane Blouin
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria.
| | - Barbara M Misof
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Matthias Mähr
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Nadja Fratzl-Zelman
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Paul Roschger
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Sonja Lueger
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Phaedra Messmer
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Petra Keplinger
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Frank Rauch
- Shriners Hospital for Children and McGill University, Montreal, ON QC, H4A 0A9, Canada
| | - Francis H Glorieux
- Shriners Hospital for Children and McGill University, Montreal, ON QC, H4A 0A9, Canada
| | - Andrea Berzlanovich
- Unit of Forensic Gerontology, Center of Forensic Medicine, Medical University of Vienna, Vienna, Austria
| | - Gerlinde M Gruber
- Department of Anatomy and Biomechanics, Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Peter C Brugger
- Center for Anatomy and Cell Biology, Department of Anatomy, Medical University of Vienna, Vienna, Austria
| | - Elizabeth Shane
- Department of Medicine, Division of Endocrinology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Robert R Recker
- Osteoporosis Research Center, Creighton University, Omaha, Nebraska, USA
| | - Jochen Zwerina
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Markus A Hartmann
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
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20
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Tang T, Landis W, Blouin S, Bertinetti L, Hartmann MA, Berzlanovich A, Weinkamer R, Wagermaier W, Fratzl P. Subcanalicular Nanochannel Volume Is Inversely Correlated With Calcium Content in Human Cortical Bone. J Bone Miner Res 2023; 38:313-325. [PMID: 36433915 DOI: 10.1002/jbmr.4753] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 11/10/2022] [Accepted: 11/23/2022] [Indexed: 11/27/2022]
Abstract
The spatial distribution of mineralization density is an important signature of bone growth and remodeling processes, and its alterations are often related to disease. The extracellular matrix of some vertebrate mineralized tissues is known to be perfused by a lacunocanalicular network (LCN), a fluid-filled unmineralized structure that harbors osteocytes and their fine processes and transports extracellular fluid and its constituents. The current report provides evidence for structural and compositional heterogeneity at an even smaller, subcanalicular scale. The work reveals an extensive unmineralized three-dimensional (3D) network of nanochannels (~30 nm in diameter) penetrating the mineralized extracellular matrix of human femoral cortical bone and encompassing a greater volume fraction and surface area than these same parameters of the canaliculi comprising the LCN. The present study combines high-resolution focused ion beam-scanning electron microscopy (FIB-SEM) to investigate bone ultrastructure in 3D with quantitative backscattered electron imaging (qBEI) to estimate local bone mineral content. The presence of nanochannels has been found to impact qBEI measurements fundamentally, such that volume percentage (vol%) of nanochannels correlates inversely with weight percentage (wt%) of calcium. This mathematical relationship between nanochannel vol% and calcium wt% suggests that the nanochannels could potentially provide space for ion and small molecule transport throughout the bone matrix. Collectively, these data propose a reinterpretation of qBEI measurements, accounting for nanochannel presence in human bone tissue in addition to collagen and mineral. Further, the results yield insight into bone mineralization processes at the nanometer scale and present the possibility for a potential role of the nanochannel system in permitting ion and small molecule diffusion throughout the extracellular matrix. Such a possible function could thereby lead to the sequestration or occlusion of the ions and small molecules within the extracellular matrix. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Tengteng Tang
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - William Landis
- Department of Preventive and Restorative Dental Sciences, University of California at San Francisco, San Francisco, CA, USA
| | - Stéphane Blouin
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Med. Department Hanusch Hospital, Vienna, Austria
| | - Luca Bertinetti
- Center for Molecular Bioengineering, TU Dresden, Dresden, Germany
| | - Markus A Hartmann
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Med. Department Hanusch Hospital, Vienna, Austria
| | | | - Richard Weinkamer
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Wolfgang Wagermaier
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Peter Fratzl
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
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Heveran CM, Boerckel JD. Osteocyte Remodeling of the Lacunar-Canalicular System: What's in a Name? Curr Osteoporos Rep 2023; 21:11-20. [PMID: 36512204 DOI: 10.1007/s11914-022-00766-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/18/2022] [Indexed: 12/15/2022]
Abstract
PURPOSE OF REVIEW Osteocytes directly modify the bone surrounding the expansive lacunar-canalicular system (LCS) through both resorption and deposition. The existence of this phenomenon is now widely accepted, but is referred to as "osteocyte osteolysis," "LCS remodeling," and "perilacunar remodeling," among other names. The uncertainty in naming this physiological process reflects the many persistent questions about why and how osteocytes interact with local bone matrix. The goal of this review is to examine the purpose and nature of LCS remodeling and its impacts on multiscale bone quality. RECENT FINDINGS While LCS remodeling is clearly important for systemic calcium mobilization, this process may have additional potential drivers and may impact the ability of bone to resist fracture. There is abundant evidence that the osteocyte can resorb and replace bone mineral and does so outside of extreme challenges to mineral homeostasis. The impacts of the osteocyte on organic matrix are less certain, especially regarding whether osteocytes produce osteoid. Though multiple lines of evidence point towards osteocyte production of organic matrix, definitive work is needed. Recent high-resolution imaging studies demonstrate that LCS remodeling influences local material properties. The role of LCS remodeling in the maintenance and deterioration of bone matrix quality in aging and disease are active areas of research. In this review, we highlight current progress in understanding why and how the osteocyte removes and replaces bone tissue and the consequences of these activities to bone quality. We posit that answering these questions is essential for evaluating whether, how, when, and why LCS remodeling may be manipulated for therapeutic benefit in managing bone fragility.
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Affiliation(s)
- C M Heveran
- Department of Mechanical & Industrial Engineering, Montana State University, Bozeman, USA.
| | - J D Boerckel
- Department of Orthopaedic Surgery, Department of Bioengineering, University of Pennsylvania School of Medicine, Philadelphia, USA.
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22
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Sato M, Shah FA. Contributions of Resin Cast Etching to Visualising the Osteocyte Lacuno-Canalicular Network Architecture in Bone Biology and Tissue Engineering. Calcif Tissue Int 2023; 112:525-542. [PMID: 36611094 PMCID: PMC10106349 DOI: 10.1007/s00223-022-01058-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 12/21/2022] [Indexed: 01/09/2023]
Abstract
Recent years have witnessed an evolution of imaging technologies towards sophisticated approaches for visualising cells within their natural environment(s) and for investigating their interactions with other cells, with adjacent anatomical structures, and with implanted biomaterials. Resin cast etching (RCE) is an uncomplicated technique involving sequential acid etching and alkali digestion of resin embedded bone to observe the osteocyte lacuno-canalicular network using scanning electron microscopy. This review summarises the applicability of RCE to bone and the bone-implant interface. Quantitative parameters such as osteocyte size, osteocyte density, and number of canaliculi per osteocyte, and qualitative metrics including osteocyte shape, disturbances in the arrangement of osteocytes and canaliculi, and physical communication between osteocytes and implant surfaces can be investigated. Ageing, osteoporosis, long-term immobilisation, spinal cord injury, osteoarthritis, irradiation, and chronic kidney disease have been shown to impact osteocyte lacuno-canalicular network morphology. In addition to titanium, calcium phosphates, and bioactive glass, observation of direct connectivity between osteocytes and cobalt chromium provides new insights into the osseointegration potential of materials conventionally viewed as non-osseointegrating. Other applications include in vivo and in vitro testing of polymer-based tissue engineering scaffolds and tissue-engineered ossicles, validation of ectopic osteochondral defect models, ex vivo organ culture of whole bones, and observing the effects of gene dysfunction/deletion on the osteocyte lacuno-canalicular network. Without additional contrast staining, any resin embedded specimen (including clinical biopsies) can be used for RCE. The multitude of applications described here attest to the versatility of RCE for routine use within correlative analytical workflows, particularly in biomaterials science.
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Affiliation(s)
- Mari Sato
- Oral Biochemistry and Molecular Biology, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan
| | - Furqan A Shah
- Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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23
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Wölfel EM, Lademann F, Hemmatian H, Blouin S, Messmer P, Hofbauer LC, Busse B, Rauner M, Jähn-Rickert K, Tsourdi E. Reduced Bone Mass and Increased Osteocyte Tartrate-Resistant Acid Phosphatase (TRAP) Activity, But Not Low Mineralized Matrix Around Osteocyte Lacunae, Are Restored After Recovery From Exogenous Hyperthyroidism in Male Mice. J Bone Miner Res 2023; 38:131-143. [PMID: 36331133 DOI: 10.1002/jbmr.4736] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 10/28/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022]
Abstract
Hyperthyroidism causes secondary osteoporosis through favoring bone resorption over bone formation, leading to bone loss with elevated bone fragility. Osteocytes that reside within lacunae inside the mineralized bone matrix orchestrate the process of bone remodeling and can themselves actively resorb bone upon certain stimuli. Nevertheless, the interaction between thyroid hormones and osteocytes and the impact of hyperthyroidism on osteocyte cell function are still unknown. In a preliminary study, we analyzed bones from male C57BL/6 mice with drug-induced hyperthyroidism, which led to mild osteocytic osteolysis with 1.14-fold larger osteocyte lacunae and by 108.33% higher tartrate-resistant acid phosphatase (TRAP) activity in osteocytes of hyperthyroid mice compared to euthyroid mice. To test whether hyperthyroidism-induced bone changes are reversible, we rendered male mice hyperthyroid by adding levothyroxine into their drinking water for 4 weeks, followed by a weaning period of 4 weeks with access to normal drinking water. Hyperthyroid mice displayed cortical and trabecular bone loss due to high bone turnover, which recovered with weaning. Although canalicular number and osteocyte lacunar area were similar in euthyroid, hyperthyroid and weaned mice, the number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL)-positive osteocytes was 100% lower in the weaning group compared to euthyroid mice and the osteocytic TRAP activity was eightfold higher in hyperthyroid animals. The latter, along with a 3.75% lower average mineralization around the osteocyte lacunae in trabecular bone, suggests osteocytic osteolysis activity that, however, did not result in significantly enlarged osteocyte lacunae. In conclusion, we show a recovery of bone microarchitecture and turnover after reversal of hyperthyroidism to a euthyroid state. In contrast, osteocytic osteolysis was initiated in hyperthyroidism, but its effects were not reversed after 4 weeks of weaning. Due to the vast number of osteocytes in bone, we speculate that even minor individual cell functions might contribute to altered bone quality and mineral homeostasis in the setting of hyperthyroidism-induced bone disease. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Eva Maria Wölfel
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Franziska Lademann
- Department of Medicine III, Technische Universität Dresden Medical Center, Dresden, Germany.,Center for Healthy Aging, Technische Universität Dresden Medical Center, Dresden, Germany
| | - Haniyeh Hemmatian
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stéphane Blouin
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria.,Vienna Bone and Growth Center, Vienna, Austria
| | - Phaedra Messmer
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria.,Vienna Bone and Growth Center, Vienna, Austria
| | - Lorenz C Hofbauer
- Department of Medicine III, Technische Universität Dresden Medical Center, Dresden, Germany.,Center for Healthy Aging, Technische Universität Dresden Medical Center, Dresden, Germany
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Martina Rauner
- Department of Medicine III, Technische Universität Dresden Medical Center, Dresden, Germany.,Center for Healthy Aging, Technische Universität Dresden Medical Center, Dresden, Germany
| | - Katharina Jähn-Rickert
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Mildred Scheel Cancer Career Center Hamburg, University Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Elena Tsourdi
- Department of Medicine III, Technische Universität Dresden Medical Center, Dresden, Germany.,Center for Healthy Aging, Technische Universität Dresden Medical Center, Dresden, Germany
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24
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Wild S, Mahr C, Rosenauer A, Risse T, Vasenkov S, Bäumer M. New Perspectives for Evaluating the Mass Transport in Porous Catalysts and Unfolding Macro- and Microkinetics. Catal Letters 2022; 153:3405-3422. [PMID: 37799191 PMCID: PMC10547662 DOI: 10.1007/s10562-022-04218-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 11/11/2022] [Indexed: 12/13/2022]
Abstract
In this article we shed light on newly emerging perspectives to characterize and understand the interplay of diffusive mass transport and surface catalytic processes in pores of gas phase metal catalysts. As a case study, nanoporous gold, as an interesting example exhibiting a well-defined pore structure and a high activity for total and partial oxidation reactions is considered. PFG NMR (pulsed field gradient nuclear magnetic resonance) measurements allowed here for a quantitative evaluation of gas diffusivities within the material. STEM (scanning transmission electron microscopy) tomography furthermore provided additional insight into the structural details of the pore system, helping to judge which of its features are most decisive for slowing down mass transport. Based on the quantitative knowledge about the diffusion coefficients inside a porous catalyst, it becomes possible to disentangle mass transport contributions form the measured reaction kinetics and to determine the kinetic rate constant of the underlying catalytic surface reaction. In addition, predictions can be made for an improved effectiveness of the catalyst, i.e., optimized conversion rates. This approach will be discussed at the example of low-temperature CO oxidation, efficiently catalysed by npAu at 30 °C. The case study shall reveal that novel porous materials exhibiting well-defined micro- and mesoscopic features and sufficient catalytic activity, in combination with modern techniques to evaluate diffusive transport, offer interesting new opportunities for an integral understanding of catalytic processes. Graphical Abstract
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Affiliation(s)
- Stefan Wild
- Institute for Applied and Physical Chemistry, University of Bremen, 28359 Bremen, Germany
- MAPEX Center of Materials and Processes, University of Bremen, 28359 Bremen, Germany
| | - Christoph Mahr
- MAPEX Center of Materials and Processes, University of Bremen, 28359 Bremen, Germany
- Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany
| | - Andreas Rosenauer
- MAPEX Center of Materials and Processes, University of Bremen, 28359 Bremen, Germany
- Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany
| | - Thomas Risse
- Institute of Chemistry and Biochemistry, Free University Berlin, 14195 Berlin, Germany
| | - Sergey Vasenkov
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611 USA
| | - Marcus Bäumer
- Institute for Applied and Physical Chemistry, University of Bremen, 28359 Bremen, Germany
- MAPEX Center of Materials and Processes, University of Bremen, 28359 Bremen, Germany
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25
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Zhang K, Ogando C, Filip A, Zhang T, Horton JA, Soman P. In vitromodel to study confined osteocyte networks exposed to flow-induced mechanical stimuli. Biomed Mater 2022; 17:10.1088/1748-605X/aca37c. [PMID: 36384043 PMCID: PMC10642715 DOI: 10.1088/1748-605x/aca37c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 11/16/2022] [Indexed: 11/18/2022]
Abstract
Osteocytes are considered the primary mechanical sensor in bone tissue and orchestrate the coupled bone remodeling activity of adjacent osteoblast and osteoclast cells.In vivoinvestigation of mechanically induced signal propagation through networks of interconnected osteocytes is confounded by their confinement within the mineralized bone matrix, which cannot be modeled in conventional culture systems. In this study, we developed a new model that mimics thisin vivoconfinement using gelatin methacrylate (GelMA) hydrogel or GelMA mineralized using osteoblast-like model cells. This model also enables real-time optical examination of osteocyte calcium (Ca2+) signaling dynamics in response to fluid shear stimuli cultured under confined conditions. Using this system, we discovered several distinct and previously undescribed patterns of Ca2+responses that vary across networks of interconnected osteocytes as a function of space, time and connectivity. Heterogeneity in Ca2+signaling may provide new insights into bone remodeling in response to mechanical loading. Overall, such a model can be extended to study signaling dynamics within cell networks exposed to flow-induced mechanical stimuli under confined conditions.
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Affiliation(s)
- Kairui Zhang
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, USA, 13244
- Syracuse Biomaterials Institute, Syracuse, NY, USA, 13244
| | - Courtney Ogando
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, USA, 13244
- Syracuse Biomaterials Institute, Syracuse, NY, USA, 13244
| | - Alex Filip
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, USA, 13244
- Syracuse Biomaterials Institute, Syracuse, NY, USA, 13244
| | - Teng Zhang
- Syracuse Biomaterials Institute, Syracuse, NY, USA, 13244
- Department of Mechanical and Aerospace Engineering, Syracuse University, Syracuse, NY, USA, 13244
| | - Jason A. Horton
- Syracuse Biomaterials Institute, Syracuse, NY, USA, 13244
- Dept. of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, NY, USA 13210
| | - Pranav Soman
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, USA, 13244
- Syracuse Biomaterials Institute, Syracuse, NY, USA, 13244
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26
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Hedjazi G, Guterman-Ram G, Blouin S, Schemenz V, Wagermaier W, Fratzl P, Hartmann MA, Zwerina J, Fratzl-Zelman N, Marini JC. Alterations of bone material properties in growing Ifitm5/BRIL p.S42 knock-in mice, a new model for atypical type VI osteogenesis imperfecta. Bone 2022; 162:116451. [PMID: 35654352 PMCID: PMC11162744 DOI: 10.1016/j.bone.2022.116451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 05/17/2022] [Accepted: 05/25/2022] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Osteogenesis imperfecta (OI) is a heterogenous group of heritable connective tissue disorders characterized by high bone fragility due to low bone mass and impaired bone material properties. Atypical type VI OI is an extremely rare and severe form of bone dysplasia resulting from a loss-of-function mutation (p.S40L) in IFITM5/BRIL,the causative gene of OI type V and decreased osteoblast secretion of pigment epithelium-derived factor (PEDF), as in OI type VI. It is not yet known which alterations at the material level might lead to such a severe phenotype. We therefore characterized bone tissue at the micrometer level in a novel heterozygous Ifitm5/BRIL p.S42L knock-in murine model at 4 and 8 weeks of age. METHODS We evaluated in female mice, total body size, femoral and lumbar bone mineral density (BMD) by dual-energy X-ray absorptiometry. In the femoral bone we examined osteoid deposition by light microscopy, assessed bone histomorphometry and mineralization density distribution by quantitative backscattered electron imaging (qBEI). Osteocyte lacunae were examined by qBEI and the osteocyte lacuno-canalicular network by confocal laser scanning microscopy. Vasculature was examined indirectly by qBEI as 2D porosity in cortex, and as 3D porosity by micro-CT in third trochanter. Collagen orientation was examined by second harmonic generation microscopy. Two-way ANOVA was used to discriminate the effect of age and genotype. RESULTS Ifitm5/BRIL p.S42L female mice are viable, do not differ in body size, fat and lean mass from wild type (WT) littermates but have lower whole-body, lumbar and femoral BMD and multiple fractures. The average and most frequent calcium concentration, CaMean and CaPeak, increased with age in metaphyseal and cortical bone in both genotypes and were always higher in Ifitm5/BRIL p.S42L than in WT, except CaMean in metaphysis at 4 weeks of age. The fraction of highly mineralized bone area, CaHigh, was also increased in Ifitm5/BRIL p.S42L metaphyseal bone at 8 weeks of age and at both ages in cortical bone. The fraction of lowly mineralized bone area, CaLow, decreased with age and was not higher in Ifitm5/BRIL p.S42L, consistent with lack of hyperosteoidosis on histological sections by visual exam. Osteocyte lacunae density was higher in Ifitm5/BRIL p.S42L than WT, whereas canalicular density was decreased. Indirect measurements of vascularity revealed a higher pore density at 4 weeks in cortical bone of Ifitm5/BRIL p.S42L than in WT and at both ages in the third trochanter. Importantly, the proportion of bone area with disordered collagen fibrils was highly increased in Ifitm5/BRIL p.S42L at both ages. CONCLUSIONS Despite normal skeletal growth and the lack of a collagen gene mutation, the Ifitm5/BRIL p.S42L mouse shows major OI-related bone tissue alterations such as hypermineralization of the matrix and elevated osteocyte porosity. Together with the disordered lacuno-canalicular network and the disordered collagen fibril orientation, these abnormalities likely contribute to overall bone fragility.
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Affiliation(s)
- Ghazal Hedjazi
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Heinrich Collin Strasse 30, 1140 Vienna, Austria
| | - Gali Guterman-Ram
- Section on Heritable Disorders of Bone and Extracellular Matrix, NICHD, NIH, Bethesda, USA
| | - Stéphane Blouin
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Heinrich Collin Strasse 30, 1140 Vienna, Austria; Vienna Bone and Growth Center, Vienna, Austria
| | - Victoria Schemenz
- Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Wolfgang Wagermaier
- Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Peter Fratzl
- Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Markus A Hartmann
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Heinrich Collin Strasse 30, 1140 Vienna, Austria; Vienna Bone and Growth Center, Vienna, Austria
| | - Jochen Zwerina
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Heinrich Collin Strasse 30, 1140 Vienna, Austria; Vienna Bone and Growth Center, Vienna, Austria
| | - Nadja Fratzl-Zelman
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Heinrich Collin Strasse 30, 1140 Vienna, Austria; Vienna Bone and Growth Center, Vienna, Austria
| | - Joan C Marini
- Section on Heritable Disorders of Bone and Extracellular Matrix, NICHD, NIH, Bethesda, USA.
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Titanium nanotopography induces osteocyte lacunar-canalicular networks to strengthen osseointegration. Acta Biomater 2022; 151:613-627. [PMID: 35995407 DOI: 10.1016/j.actbio.2022.08.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 08/09/2022] [Accepted: 08/12/2022] [Indexed: 11/20/2022]
Abstract
Osteocyte network architecture is closely associated with bone turnover. The cellular mechanosensing system regulates osteocyte dendrite formation by enhancing focal adhesion. Therefore, titanium surface nanotopography might affect osteocyte network architecture and improve the peri-implant bone tissue quality, leading to strengthened osseointegration of bone-anchored implants. We aimed to investigate the effects of titanium nanosurfaces on the development of osteocyte lacunar-canalicular networks and osseointegration of dental implants. Alkaline etching created titanium nanosurfaces with anisotropically patterned dense nanospikes, superhydrophilicity, and hydroxyl groups. MLO-Y4 mouse osteocyte-like cells cultured on titanium nanosurfaces developed neuron-like dendrites with increased focal adhesion assembly and gap junctions. Maturation was promoted in osteocytes cultured on titanium nanosurfaces compared to cells cultured on machined or acid-etched micro-roughened titanium surfaces. Osteocytes cultured in type I three-dimensional collagen gels for seven days on nano-roughened titanium surfaces displayed well-developed interconnectivity with highly developed dendrites and gap junctions compared to the poor interconnectivity observed on the other titanium surfaces. Even if superhydrophilicity and hydroxyl groups were maintained, the loss of anisotropy-patterned nanospikes reduced expression of gap junction in osteocytes cultured on alkaline-etched titanium nanosurfaces. Four weeks after placing the titanium nanosurface implants in the upper jawbone of wild-type rats, osteocytes with numerous dendrites were found directly attached to the implant surface, forming well-developed lacunar-canalicular networks around the nano-roughened titanium implants. The osseointegration strength of the nano-roughened titanium implants was significantly higher than that of the micro-roughened titanium implants. These data indicate that titanium nanosurfaces promote osteocyte lacunar-canalicular network development via nanotopographical cues and strengthen osseointegration. STATEMENT OF SIGNIFICANCE: The clinical stability of bone-anchoring implant devices is influenced by the bone quality. The osteocyte network potentially affects bone quality and is established by the three-dimensional (3D) connection of neuron-like dendrites of well-matured osteocytes within the bone matrix. No biomaterials are known to regulate formation of the osteocyte network. The present study provides the first demonstration that titanium nanosurfaces with nanospikes created by alkali-etching treatment enhance the 3D formation of osteocyte networks by promoting osteocyte dendrite formation and maturation by nanotopographic cues, leading to strengthened osseointegration of titanium implants. Osteocytes attached to the titanium nanosurfaces via numerous cellular projections. The success of osteocyte regulation by nanotechnology paves the way for development of epoch-making technologies to control bone quality.
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Žerovnik Mekuč M, Bohak C, Boneš E, Hudoklin S, Romih R, Marolt M. Automatic segmentation and reconstruction of intracellular compartments in volumetric electron microscopy data. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 223:106959. [PMID: 35763876 DOI: 10.1016/j.cmpb.2022.106959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 02/02/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND AND OBJECTIVES In recent years, electron microscopy is enabling the acquisition of volumetric data with resolving power to directly observe the ultrastructure of intracellular compartments. New insights and knowledge about cell processes that are offered by such data require a comprehensive analysis which is limited by the time-consuming manual segmentation and reconstruction methods. METHOD We present methods for automatic segmentation, reconstruction, and analysis of intracellular compartments from volumetric data obtained by the dual-beam electron microscopy. We specifically address segmentation of fusiform vesicles and the Golgi apparatus, reconstruction of mitochondria and fusiform vesicles, and morphological analysis of the reconstructed mitochondria. RESULTS AND CONCLUSION Evaluation on the public UroCell dataset demonstrated high accuracy of the proposed methods for segmentation of fusiform vesicles and the Golgi apparatus, as well as for reconstruction of mitochondria and analysis of their shapes, while reconstruction of fusiform vesicles proved to be more challenging. We published an extension of the UroCell dataset with all of the data used in this work, to further contribute to research on automatic analysis of the ultrastructure of intracellular compartments.
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Affiliation(s)
- Manca Žerovnik Mekuč
- Faculty of Computer and Information Science, University of Ljubljana, Večna pot 113, Ljubljana 1000, Slovenia.
| | - Ciril Bohak
- Faculty of Computer and Information Science, University of Ljubljana, Večna pot 113, Ljubljana 1000, Slovenia; Visual Computing Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
| | - Eva Boneš
- Faculty of Computer and Information Science, University of Ljubljana, Večna pot 113, Ljubljana 1000, Slovenia.
| | - Samo Hudoklin
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, Ljubljana 1000, Slovenia.
| | - Rok Romih
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, Ljubljana 1000, Slovenia.
| | - Matija Marolt
- Faculty of Computer and Information Science, University of Ljubljana, Večna pot 113, Ljubljana 1000, Slovenia; Faculty of Computer and Information Science, University of Ljubljana, Večna pot 113, Ljubljana 1000, Slovenia.
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Tang H, Bober RR, Zhao C, Zhang C, Zhu H, He Z, Xu Z, Zhou W. 3D fusion between fluoroscopy angiograms and SPECT myocardial perfusion images to guide percutaneous coronary intervention. J Nucl Cardiol 2022; 29:1870-1884. [PMID: 33825145 PMCID: PMC10982818 DOI: 10.1007/s12350-021-02574-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 02/03/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Percutaneous coronary intervention (PCI) in stable coronary artery disease (CAD) is commonly triggered by abnormal myocardial perfusion imaging (MPI). However, due to the possibilities of multivessel disease, serial stenoses and variability of coronary artery perfusion distribution, an opportunity exists to better align anatomic stenosis with perfusion abnormalities to improve revascularization decisions. This study aims to develop a multi-modality fusion approach to assist decision-making for PCI. METHODS AND RESULTS Coronary arteries from fluoroscopic angiography (FA) were reconstructed into 3D artery anatomy. Left ventricular (LV) epicardial surface was extracted from SPECT. The artery anatomy and epicardial surface were non-rigidly fused. The accuracy of the 3D fusion was evaluated via both computer simulation and real patient data. Simulated FA and MPI were integrated and then compared with the ground truth from a digital phantom. The distance-based mismatch errors between simulated fluoroscopy and phantom arteries were 1.86 ± 1.43 mm for left coronary arteries (LCA) and 2.21 ± 2.50 mm for right coronary arteries (RCA). FA and SPECT images in 30 patients were integrated and then compared with the ground truth from CT angiograms. The distance-based mismatch errors between the fluoroscopy and CT arteries were 3.84 ± 3.15 mm for LCA and 5.55 ± 3.64 mm for RCA. The presence of the corresponding fluoroscopy and CT arteries in the AHA-17-segment model agreed well with a Kappa value of 0.91 (CI 0.89-0.93) for LCA and a Kappa value of 0.80 (CI 0.67-0.92) for RCA. CONCLUSIONS Our fusion approach is technically accurate to assist PCI decision-making and is clinically feasible to be used in the catheterization laboratory. Future studies are necessary to determine if fusion improves PCI-related outcomes.
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Affiliation(s)
- Haipeng Tang
- School of Computing Sciences and Computer Engineering, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Robert R Bober
- Department of Cardiology, Ochsner Medical Center, New Orleans, LA, 70121, USA
| | - Chen Zhao
- Department of Applied Computing, Michigan Technological University, 1400 Townsend Dr, Houghton, MI, 49931, USA
| | - Chaoyang Zhang
- School of Computing Sciences and Computer Engineering, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Huiqing Zhu
- School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Zhuo He
- Department of Applied Computing, Michigan Technological University, 1400 Townsend Dr, Houghton, MI, 49931, USA
| | - Zhihui Xu
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Rd, Nanjing, 210000, China.
| | - Weihua Zhou
- Department of Applied Computing, Michigan Technological University, 1400 Townsend Dr, Houghton, MI, 49931, USA.
- Center of Biocomputing and Digital Health, Institute of Computing and Cybersystems, and Health Research Institute, Michigan Technological University, Houghton, MI, 49931, USA.
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Wittig NK, Birkedal H. Bone hierarchical structure: spatial variation across length scales. ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2022; 78:305-311. [PMID: 35695104 DOI: 10.1107/s2052520622001524] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 02/08/2022] [Indexed: 06/15/2023]
Abstract
Bone is a complex hierarchical biomineralized material, which is special amongst biominerals because it is replete with cells, namely, osteocytes. While bone has been scrutinized for centuries, many questions remain open and new research hints that the ultrastructure of bone, encompassing both the bone matrix itself and the embedded cell network, is much more heterogeneous than hitherto realized. A number of these new findings have been made thanks to the enormous developments in X-ray imaging that have occurred in recent decades, and there is promise that they will also allow many of the remaining open questions to be addressed. X-ray absorption or phase imaging affords high three-dimensional (3D) resolution and allows traversing the length scales of bone all the way down to the fine details of the lacuno-canalicular network housing the osteocytes. Multimodal X-ray imaging provides combined information covering both the length scales defined by the size of the measured volume and tomographic resolution, as well as those probed by the signal that is measured. In X-ray diffraction computed tomography (XRD-CT), for example, diffraction signals can be reconstructed tomographically, which offers detailed information about the spatial variations in the crystallographic properties of the bone biomineral. Orientational information can be obtained by tensor tomography. The combination of both small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) tensor tomography gives information on the orientation of bone nanostructure and crystals, respectively. These new technical developments promise that great strides towards understanding bone structure can be expected in the near future. In this review, recent findings that have resulted from X-ray imaging are highlighted and speculation is given on what can be expected to follow.
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Affiliation(s)
- Nina K Wittig
- Department of Chemistry and iNANO, Aarhus University, 14 Gustav Wieds Vej, Aarhus 8000, Denmark
| | - Henrik Birkedal
- Department of Chemistry and iNANO, Aarhus University, 14 Gustav Wieds Vej, Aarhus 8000, Denmark
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31
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Thies M, Wagner F, Huang Y, Gu M, Kling L, Pechmann S, Aust O, Grüneboom A, Schett G, Christiansen S, Maier A. Calibration by differentiation - Self-supervised calibration for X-ray microscopy using a differentiable cone-beam reconstruction operator. J Microsc 2022; 287:81-92. [PMID: 35638174 DOI: 10.1111/jmi.13125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 04/20/2022] [Accepted: 05/22/2022] [Indexed: 11/28/2022]
Abstract
High-resolution X-ray microscopy (XRM) is gaining interest for biological investigations of extremely small-scale structures. XRM imaging of bones in living mice could provide new insights into the emergence and treatment of osteoporosis by observing osteocyte lacunae, which are holes in the bone of few micrometers in size. Imaging living animals at that resolution, however, is extremely challenging and requires very sophisticated data processing converting the raw XRM detector output into reconstructed images. This paper presents an open-source, differentiable reconstruction pipeline for XRM data which analytically computes the final image from the raw measurements. In contrast to most proprietary reconstruction software, it offers the user full control over each processing step and, additionally, makes the entire pipeline deep learning compatible by ensuring differentiability. This allows fitting trainable modules both before and after the actual reconstruction step in a purely data-driven way using the gradient-based optimizers of common deep learning frameworks. The value of such differentiability is demonstrated by calibrating the parameters of a simple cupping correction module operating on the raw projection images using only a self-supervisory quality metric based on the reconstructed volume and no further calibration measurements. The retrospective calibration directly improves image quality as it avoids cupping artifacts and decreases the difference in gray values between outer and inner bone by 68% to 94%. Furthermore, it makes the reconstruction process entirely independent of the XRM manufacturer and paves the way to explore modern deep learning reconstruction methods for arbitrary XRM and, potentially, other flat-panel CT systems. This exemplifies how differentiable reconstruction can be leveraged in the context of XRM and, hence, is an important step toward the goal of reducing the resolution limit of in-vivo bone imaging to the single micrometer domain. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Mareike Thies
- Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Fabian Wagner
- Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Yixing Huang
- Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Mingxuan Gu
- Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Lasse Kling
- Institute for Nanotechnology and Correlative Microscopy e.V. INAM, Forchheim, Germany
| | - Sabrina Pechmann
- Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Forchheim, Germany
| | - Oliver Aust
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-Universität Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany
| | - Anika Grüneboom
- Leibniz Institute for Analytical Sciences ISAS, Dortmund, Germany
| | - Georg Schett
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-Universität Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany.,Deutsches Zentrum für Immuntherapie, Friedrich-Alexander-Universität Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany
| | - Silke Christiansen
- Institute for Nanotechnology and Correlative Microscopy e.V. INAM, Forchheim, Germany.,Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Forchheim, Germany.,Physics Department, Freie Universität Berlin, Berlin, Germany
| | - Andreas Maier
- Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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32
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Barisano G, Lynch KM, Sibilia F, Lan H, Shih NC, Sepehrband F, Choupan J. Imaging perivascular space structure and function using brain MRI. Neuroimage 2022; 257:119329. [PMID: 35609770 PMCID: PMC9233116 DOI: 10.1016/j.neuroimage.2022.119329] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/04/2022] [Accepted: 05/19/2022] [Indexed: 12/03/2022] Open
Abstract
In this article, we provide an overview of current neuroimaging methods for studying perivascular spaces (PVS) in humans using brain MRI. In recent years, an increasing number of studies highlighted the role of PVS in cerebrospinal/interstial fluid circulation and clearance of cerebral waste products and their association with neurological diseases. Novel strategies and techniques have been introduced to improve the quantification of PVS and to investigate their function and morphological features in physiological and pathological conditions. After a brief introduction on the anatomy and physiology of PVS, we examine the latest technological developments to quantitatively analyze the structure and function of PVS in humans with MRI. We describe the applications, advantages, and limitations of these methods, providing guidance and suggestions on the acquisition protocols and analysis techniques that can be applied to study PVS in vivo. Finally, we review the human neuroimaging studies on PVS across the normative lifespan and in the context of neurological disorders.
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Affiliation(s)
- Giuseppe Barisano
- Laboratory of Neuro Imaging, USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, USA; Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA..
| | - Kirsten M Lynch
- Laboratory of Neuro Imaging, USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, USA
| | - Francesca Sibilia
- Laboratory of Neuro Imaging, USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, USA
| | - Haoyou Lan
- Laboratory of Neuro Imaging, USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, USA; Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA
| | - Nien-Chu Shih
- Laboratory of Neuro Imaging, USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, USA
| | - Farshid Sepehrband
- Laboratory of Neuro Imaging, USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, USA
| | - Jeiran Choupan
- Laboratory of Neuro Imaging, USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, USA
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33
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Wang H, Du T, Li R, Main RP, Yang H. Interactive effects of various loading parameters on the fluid dynamics within the lacunar-canalicular system for a single osteocyte. Bone 2022; 158:116367. [PMID: 35181573 DOI: 10.1016/j.bone.2022.116367] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 02/11/2022] [Accepted: 02/11/2022] [Indexed: 12/26/2022]
Abstract
The osteocyte lacunar-canalicular system (LCS) serves as a mechanotransductive core where external loading applied to the skeleton is transduced into mechanical signals (e.g., fluid shear) that can be sensed by mechanosensors (osteocytes). The fluid velocity and shear stress within the LCS are affected by various loading parameters. However, the interactive effect of distinct loading parameters on the velocity and shear stress in the LCS remains unclear. To address this issue, we developed a multiscale modeling approach, combining a poroelastic finite element (FE) model with a single osteocytic LCS unit model to calculate the flow velocity and shear stress within the LCS. Next, a sensitivity analysis was performed to investigate individual and interactive effects of strain magnitude, strain rate, number of cycles, and intervening short rests between loading cycles on the velocity and shear stress around the osteocyte. Lastly, we developed a relatively simple regression model to predict those outcomes. Our results demonstrated that the strain magnitude or rate alone were the main factors affecting the velocity and shear stress; however, the combination of these two was not directly additive, and addition of a short rest between cycles could enhance the combination of these two related factors. These results show highly interactive effects of distinct loading parameters on fluid velocity and shear stress in the LCS. Specifically, our results suggest that an enhanced fluid dynamics environment in the LCS can be achieved with a brief number of load cycles combined with short rest insertion and high strain magnitude and rate.
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Affiliation(s)
- Huiru Wang
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Tianming Du
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Rui Li
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Russell P Main
- Musculoskeletal Biology and Mechanics Lab, Department of Basic Medical Sciences, Purdue University, IN, USA; Weldon School of Biomedical Engineering, Purdue University, IN, USA
| | - Haisheng Yang
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
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Wang X, Liu M, Wang Y, Fan J, Meijering E. A 3D Tubular Flux Model for Centerline Extraction in Neuron Volumetric Images. IEEE TRANSACTIONS ON MEDICAL IMAGING 2022; 41:1069-1079. [PMID: 34826295 DOI: 10.1109/tmi.2021.3130987] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Digital morphology reconstruction from neuron volumetric images is essential for computational neuroscience. The centerline of the axonal and dendritic tree provides an effective shape representation and serves as a basis for further neuron reconstruction. However, it is still a challenge to directly extract the accurate centerline from the complex neuron structure with poor image quality. In this paper, we propose a neuron centerline extraction method based on a 3D tubular flux model via a two-stage CNN framework. In the first stage, a 3D CNN is used to learn the latent neuron structure features, namely flux features, from neuron images. In the second stage, a light-weight U-Net takes the learned flux features as input to extract the centerline with a spatial weighted average strategy to constrain the multi-voxel width response. Specifically, the labels of flux features in the first stage are generated by the 3D tubular model which calculates the geometric representations of the flux between each voxel in the tubular region and the nearest point on the centerline ground truth. Compared with self-learned features by networks, flux features, as a kind of prior knowledge, explicitly take advantage of the contextual distance and direction distribution information around the centerline, which is beneficial for the precise centerline extraction. Experiments on two challenging datasets demonstrate that the proposed method outperforms other state-of-the-art methods by 18% and 35.1% in F1-measurement and average distance scores at the most, and the extracted centerline is helpful to improve the neuron reconstruction performance.
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35
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Rux CJ, Vahidi G, Darabi A, Cox LM, Heveran CM. Perilacunar bone tissue exhibits sub-micrometer modulus gradation which depends on the recency of osteocyte bone formation in both young adult and early-old-age female C57Bl/6 mice. Bone 2022; 157:116327. [PMID: 35026452 PMCID: PMC8858864 DOI: 10.1016/j.bone.2022.116327] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/19/2021] [Accepted: 01/07/2022] [Indexed: 11/18/2022]
Abstract
Osteocytes resorb and replace bone local to the lacunar-canalicular system (LCS). However, whether osteocyte remodeling impacts bone quality adjacent to the LCS is not understood. Further, while aging is well-established to decrease osteocyte viability and truncate LCS geometry, it is unclear if aging also decreases perilacunar bone quality. To address these questions, we employed atomic force microscopy (AFM) to generate nanoscale-resolution modulus maps for cortical femur osteocyte lacunae from young (5-month) and early-old-age (22-month) female C57Bl/6 mice. AFM-mapped lacunae were also imaged with confocal laser scanning microscopy to determine which osteocytes recently deposited bone as determined by the presence of fluorochrome labels administered 2d and 8d before euthanasia. Modulus gradation with distance from the lacunar wall was compared for labeled (i.e., bone forming) and non-labeled lacunae in both young and aged mice. All mapped lacunae showed sub-microscale modulus gradation, with peak modulus values 200-400 nm from the lacunar wall. Perilacunar modulus gradations depended on the recency of osteocyte bone formation (i.e., the presence of labels). For both ages, 2d-labeled perilacunar bone had lower peak and bulk modulus compared to non-labeled perilacunar bone. Lacunar length reduced with age, but lacunar shape and size were not strong predictors of modulus gradation. Our findings demonstrate for the first time that osteocyte perilacunar remodeling impacts bone tissue modulus, one contributor to bone quality. Given the immense scale of the LCS, differences in perilacunar modulus resulting from osteocyte remodeling activity may affect the quality of a substantial amount of bone tissue.
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Affiliation(s)
- Caleb J Rux
- Department of Mechanical & Industrial Engineering, Montana State University, United States of America; UC Berkeley-UCSF Graduate Program in Bioengineering, United States of America
| | - Ghazal Vahidi
- Department of Mechanical & Industrial Engineering, Montana State University, United States of America
| | - Amir Darabi
- Department of Mechanical & Industrial Engineering, Montana State University, United States of America
| | - Lewis M Cox
- Department of Mechanical & Industrial Engineering, Montana State University, United States of America
| | - Chelsea M Heveran
- Department of Mechanical & Industrial Engineering, Montana State University, United States of America.
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36
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von Kroge S, Stürznickel J, Bechler U, Stockhausen KE, Eissele J, Hubert J, Amling M, Beil FT, Busse B, Rolvien T. Impaired bone quality in the superolateral femoral neck occurs independent of hip geometry and bone mineral density. Acta Biomater 2022; 141:233-243. [PMID: 34999261 DOI: 10.1016/j.actbio.2022.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 12/30/2021] [Accepted: 01/03/2022] [Indexed: 11/01/2022]
Abstract
Skeletal adaptation is substantially influenced by mechanical loads. Osteocytes and their lacuno-canalicular network have been identified as a key player in load sensation and bone quality regulation. In the femoral neck, one of the most common fracture sites, a complex loading pattern with lower habitual loading in the superolateral neck and higher compressive stresses in the inferomedial neck is present. Variations in the femoral neck-shaft angle (NSA), i.e., coxa vara or coxa valga, provide the opportunity to examine the influence of loading patterns on bone quality. We obtained femoral neck specimens of 28 osteoarthritic human subjects with coxa vara, coxa norma and coxa valga during total hip arthroplasty. Bone mineral density (BMD) was assessed preoperatively by dual energy X-ray absorptiometry (DXA). Cortical and trabecular microstructure and three-dimensional osteocyte lacunar characteristics were assessed in the superolateral and inferomedial neck using ex vivo high resolution micro-computed tomography. Additionally, BMD distribution and osteocyte lacunar characteristics were analyzed by quantitative backscattered electron imaging (qBEI). All groups presented thicker inferomedial than superolateral cortices. Furthermore, the superolateral site exhibited a lower osteocyte lacunar density along with lower lacunar sphericity than the inferomedial site, independent of NSA. Importantly, BMD and corresponding T-scores correlated with microstructural parameters at the inferomedial but not superolateral neck. In conclusion, we provide micromorphological evidence for fracture vulnerability of the superolateral neck, which is independent of NSA and BMD. The presented bone qualitative data provide an explanation why DXA may be insufficient to predict a substantial proportion of femoral neck fractures. STATEMENT OF SIGNIFICANCE: The femoral neck, one of the most common fracture sites, is subject to a complex loading pattern. Site-specific differences (i.e., superolateral vs. inferomedial) in bone quality influence fracture risk, but it is unclear how this relates to hip geometry and bone mineral density (BMD) measurements in vivo. Here, we examine femoral neck specimens using a variety of high-resolution imaging techniques and demonstrate impaired bone quality in the superolateral compared to the inferomedial neck. Specifically, we found impaired cortical and trabecular microarchitecture, mineralization, and osteocyte properties, regardless of neck-shaft angle. Since BMD correlated with bone quality of the inferomedial but not the superolateral neck, our results illustrate why bone densitometry may not predict a substantial proportion of femoral neck fractures.
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37
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Networks behind the morphology and structural design of living systems. Phys Life Rev 2022; 41:1-21. [DOI: 10.1016/j.plrev.2022.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 03/04/2022] [Indexed: 01/06/2023]
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38
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Kao PK, Solomon MJ, Ganesan M. Microstructure and elasticity of dilute gels of colloidal discoids. SOFT MATTER 2022; 18:1350-1363. [PMID: 34932058 DOI: 10.1039/d1sm01605a] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The linear elasticity of dilute colloidal gels formed from discoidal latex particles is quantified as a function of aspect ratio and modeled by confocal microscopy characterization of their fractal cluster microstructure. Colloidal gels are of fundamental interest because of their widespread use to stabilize complex fluids in industry. Technological interest in producing gels of desired moduli using the least number of particles drives formulators to produce gels at dilute concentrations. However, dilute gels self-assembled from isotropic spheres offer limited scope for rheological tunability due to the universal characteristics of their fractal microstructure. Our results show that changing the building block shape from sphere to discoid yields very large shifts in gel elasticity relative to the universal behavior reported for spheres. This shift - tunable through aspect ratio - yields up to a 100-fold increase in elastic modulus at a fixed volume fraction. From modeling the results using the theory for fractal cluster gel rheology, which is applicable at the dilute conditions of this study, we reveal that the efficient generation of elasticity by the colloidal discoids is the consequence of the combined effects of shape anisotropy on the fractal microstructure of the gel network, the anisotropy of the attractive interparticle pair potentials, and the volumetric compactness of the fractal cluster. These results extend prior characterizations of the rheology of non-spherical particulate gels by providing quantitative estimates of how the specific mechanisms of fractality, pair potential, and clustering mediate the profound effects of particle shape anisotropy on the elastic rheology of colloidal gels.
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Affiliation(s)
- Peng-Kai Kao
- Department of Chemical Engineering, University of Michigan, North Campus Research Complex, Building 10 - A151, 2800 Plymouth Road, Ann Arbor, Michigan 48109, USA.
| | - Michael J Solomon
- Department of Chemical Engineering, University of Michigan, North Campus Research Complex, Building 10 - A151, 2800 Plymouth Road, Ann Arbor, Michigan 48109, USA.
| | - Mahesh Ganesan
- Department of Chemical Engineering, University of Michigan, North Campus Research Complex, Building 10 - A151, 2800 Plymouth Road, Ann Arbor, Michigan 48109, USA.
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39
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Li M, Matouš K, Nerenberg R. Data-driven modeling of heterogeneous viscoelastic biofilms. Biotechnol Bioeng 2022; 119:1301-1313. [PMID: 35129209 DOI: 10.1002/bit.28056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/21/2022] [Accepted: 01/30/2022] [Indexed: 11/06/2022]
Abstract
Biofilms are typically heterogeneous in morphology, structure, and composition, resulting in non-uniform mechanical properties. The distribution of mechanical properties, in turn, determines the biofilm behavior, such as deformation and detachment. Most biofilm models neglect biofilm heterogeneity, especially at the microscale. In this study, an image-based modeling approach was developed to transform two-dimensional optical coherence tomography (OCT) biofilm images to a pixel-scale non-Newtonian viscosity map of the biofilm. The map was calibrated using the bulk viscosity data from rheometer tests, based on assumed maximum and minimum viscosities and a relationship between OCT image intensity signals and non-Newtonian viscosity. While not quantitatively measuring biofilm viscosity for each pixel, it allows a rational spatial allocation of viscosities within the biofilm: areas with lower cell density, e.g., voids, are assigned lower viscosities, and areas with high cell densities are assigned higher viscosities. The spatial distribution of non-Newtonian viscosity was applied in an established Oldroyd-B constitutive model and implemented using the phase-field continuum approach for the deformation and stress analysis. The heterogeneous model was able to predict deformations more accurately than a homogenous one. Stress distribution in the heterogeneous biofilm displayed better characteristics than that in the homogeneous one, because it is highly dependent on the viscosity distribution. This work, using a pixel-scale, image-based approach to map the mechanical heterogeneity of biofilms for computational deformation and stress analysis, provides a novel modeling approach that allows the consideration of biofilm structural and mechanical heterogeneity. Future research should better characterize the relationship between OCT signal and viscosity, and consider other constitutive models for biofilm mechanical behavior. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Mengfei Li
- University of Notre Dame, Department of Civil and Environmental Engineering and Earth Sciences, 156 Fitzpatrick Hall, Notre Dame, IN, 46556, USA
| | - Karel Matouš
- University of Notre Dame, Department of Aerospace and Mechanical Engineering, Notre Dame, IN, 46556, USA
| | - Robert Nerenberg
- University of Notre Dame, Department of Civil and Environmental Engineering and Earth Sciences, 156 Fitzpatrick Hall, Notre Dame, IN, 46556, USA
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40
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Bortel E, Grover LM, Eisenstein N, Seim C, Suhonen H, Pacureanu A, Westenberger P, Raum K, Langer M, Peyrin F, Addison O, Hesse B. Interconnectivity Explains High Canalicular Network Robustness between Neighboring Osteocyte Lacunae in Human Bone. ADVANCED NANOBIOMED RESEARCH 2021. [DOI: 10.1002/anbr.202100090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Emely Bortel
- Xploraytion GmbH Bismarckstrasse 10-12 10625 Berlin Germany
| | - Liam M Grover
- School of Chemical Engineering University of Birmingham B15 2TT Birmingham UK
| | - Neil Eisenstein
- School of Chemical Engineering University of Birmingham B15 2TT Birmingham UK
| | - Christian Seim
- Xploraytion GmbH Bismarckstrasse 10-12 10625 Berlin Germany
- Technical University of Berlin: Institute of Optics and Atomic Physics 10623 Berlin Germany
| | - Heikki Suhonen
- University of Helsinki: Department of Physics 00560 Helsinki Finland
| | | | | | - Kay Raum
- Charité—Universitätsmedizin Berlin Corporate Member of Freie Universität Berlin Humboldt-Universität zu Berlinand Berlin Institute of Health BCRT—Berlin Institute of Health Center for Regenerative Therapies 13353 Berlin Germany
| | - Max Langer
- Univ Lyon CNRS 5220Inserm U1294INSA Lyon 69621 Creatis Villeurbanne Cedex France
- Université Grenoble Alpes CNRSUMR 5525 VetAgro SupGrenoble INPTIMC F-38000 Grenoble France
| | - Francoise Peyrin
- ESRF: Experiment Division 38000 Grenoble France
- Univ Lyon CNRS 5220Inserm U1294INSA Lyon 69621 Creatis Villeurbanne Cedex France
| | - Owen Addison
- Faculty of Dentistry Oral and Craniofacial Sciences Kings College SE1 9RT London UK
| | - Bernhard Hesse
- Xploraytion GmbH Bismarckstrasse 10-12 10625 Berlin Germany
- ESRF: Experiment Division 38000 Grenoble France
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Abstract
PURPOSE OF REVIEW While the function of osteocytes under physiologic conditions is well defined, their role and involvement in cancer disease remains relatively unexplored, especially in a context of non-bone metastatic cancer. This review will focus on describing the more advanced knowledge regarding the interactions between osteocytes and cancer. RECENT FINDINGS We will discuss the involvement of osteocytes in the onset and progression of osteosarcoma, with the common bone cancers, as well as the interaction that is established between osteocytes and multiple myeloma. Mechanisms responsible for cancer dissemination to bone, as frequently occur with advanced breast and prostate cancers, will be reviewed. While a role for osteocytes in the stimulation and proliferation of cancer cells has been reported, protective effects of osteocytes against bone colonization have been described as well, thus increasing ambiguity regarding the role of osteocytes in cancer progression and dissemination. Lastly, supporting the idea that skeletal defects can occur also in the absence of direct cancer dissemination or osteolytic lesions directly adjacent to the bone, our recent findings will be presented showing that in the absence of bone metastases, the bone microenvironment and, particularly, osteocytes, can manifest a clear and dramatic response to the distant, non-metastatic tumor. Our observations support new studies to clarify whether treatments designed to preserve the osteocytes can be combined with traditional anticancer therapies, even when bone is not directly affected by tumor growth.
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Affiliation(s)
- Fabrizio Pin
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Matt Prideaux
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Lynda F Bonewald
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
- Simon Comprehensive Cancer Center, Indiana University School of Medicine, Indianapolis, IN, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Andrea Bonetto
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Otolaryngology-Head & Neck Surgery, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Surgery, Indiana University School of Medicine, 980 W Walnut Street, R3-C522, Indianapolis, IN, 46202, USA.
- Simon Comprehensive Cancer Center, Indiana University School of Medicine, Indianapolis, IN, USA.
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA.
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42
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Liu H, Zhang C, Xu J, Jin J, Cheng L, Miao X, Wu Q, Wei Z, Liu P, Lu H, van Zijl PCM, Ross CA, Hua J, Duan W. Huntingtin silencing delays onset and slows progression of Huntington's disease: a biomarker study. Brain 2021; 144:3101-3113. [PMID: 34043007 PMCID: PMC8634120 DOI: 10.1093/brain/awab190] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 04/19/2021] [Accepted: 04/29/2021] [Indexed: 01/29/2023] Open
Abstract
Huntington's disease is a dominantly inherited, fatal neurodegenerative disorder caused by a CAG expansion in the huntingtin (HTT) gene, coding for pathological mutant HTT protein (mHTT). Because of its gain-of-function mechanism and monogenic aetiology, strategies to lower HTT are being actively investigated as disease-modifying therapies. Most approaches are currently targeted at the manifest stage, where clinical outcomes are used to evaluate the effectiveness of therapy. However, as almost 50% of striatal volume has been lost at the time of onset of clinical manifest, it would be preferable to begin therapy in the premanifest period. An unmet challenge is how to evaluate therapeutic efficacy before the presence of clinical symptoms as outcome measures. To address this, we aim to develop non-invasive sensitive biomarkers that provide insight into therapeutic efficacy in the premanifest stage of Huntington's disease. In this study, we mapped the temporal trajectories of arteriolar cerebral blood volumes (CBVa) using inflow-based vascular-space-occupancy (iVASO) MRI in the heterozygous zQ175 mice, a full-length mHTT expressing and slowly progressing model with a premanifest period as in human Huntington's disease. Significantly elevated CBVa was evident in premanifest zQ175 mice prior to motor deficits and striatal atrophy, recapitulating altered CBVa in human premanifest Huntington's disease. CRISPR/Cas9-mediated non-allele-specific HTT silencing in striatal neurons restored altered CBVa in premanifest zQ175 mice, delayed onset of striatal atrophy, and slowed the progression of motor phenotype and brain pathology. This study-for the first time-shows that a non-invasive functional MRI measure detects therapeutic efficacy in the premanifest stage and demonstrates long-term benefits of a non-allele-selective HTT silencing treatment introduced in the premanifest Huntington's disease.
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Affiliation(s)
- Hongshuai Liu
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Chuangchuang Zhang
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jiadi Xu
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- The Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jing Jin
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Liam Cheng
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Xinyuan Miao
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- The Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Qian Wu
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Zhiliang Wei
- The Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Peiying Liu
- The Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Hanzhang Lu
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- The Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Peter C M van Zijl
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- The Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Christopher A Ross
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jun Hua
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- The Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Wenzhen Duan
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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43
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Mäkitie RE, Blouin S, Välimäki VV, Pihlström S, Määttä K, Pekkinen M, Fratzl-Zelman N, Mäkitie O, Hartmann MA. Abnormal Bone Tissue Organization and Osteocyte Lacunocanalicular Network in Early-Onset Osteoporosis Due to SGMS2 Mutations. JBMR Plus 2021; 5:e10537. [PMID: 34761145 PMCID: PMC8567487 DOI: 10.1002/jbm4.10537] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 08/05/2021] [Indexed: 11/08/2022] Open
Abstract
Pathological variants in SGMS2, encoding sphingomyelin synthase 2 (SMS2), result in a rare autosomal dominant skeletal disorder with cranial doughnut lesions. The disease manifests as early-onset osteoporosis or a more severe skeletal dysplasia with low bone mineral density, frequent fractures, long-bone deformities, and multiple sclerotic cranial lesions. The exact underlying molecular features and skeletal consequences, however, remain elusive. This study investigated bone tissue characteristics in two adult males with a heterozygous SGMS2 mutation p.Arg50* and significant bone fragility. Transiliac bone biopsy samples from both (patient 1: 61 years; patient 2: 29 years) were analyzed by bone histomorphometry, confocal laser scanning microscopy, and quantitative backscattered electron imaging (qBEI). Bone histomorphometry portrayed largely normal values for structural and turnover parameters, but in both patient 1 and patient 2, respectively, osteoid thickness (-1.80 SD, -1.37 SD) and mineralizing surface (-1.03 SD, -2.73 SD) were reduced and osteoid surface increased (+9.03 SD, +0.98 SD), leading to elevated mineralization lag time (+8.16 SD, +4.10 SD). qBEI showed low and heterogeneous matrix mineralization (CaPeak -2.41 SD, -3.72 SD; CaWidth +7.47 SD, +4.41 SD) with a chaotic arrangement of collagenous fibrils under polarized light. Last, osteocyte lacunae appeared abnormally large and round in shape and the canalicular network severely disturbed with short-spanned canaliculi lacking any orderliness or continuity. Taken together, these data underline a central role for functional SMS2 in bone matrix organization and mineralization, lacunocanalicular network, and in maintaining skeletal strength and integrity. These data bring new knowledge on changes in bone histology resulting from abnormal sphingomyelin metabolism and aid en route to better understanding of sphingolipid-related skeletal disorders. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Riikka E Mäkitie
- Folkhälsan Institute of Genetics Helsinki Finland.,Research Program for Clinical and Molecular Metabolism, Faculty of Medicine University of Helsinki Helsinki Finland.,Department of Otorhinolaryngology-Head and Neck Surgery Helsinki University Hospital and University of Helsinki Helsinki Finland
| | - Stéphane Blouin
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital Vienna Austria.,Vienna Bone and Growth Center Vienna Austria
| | | | - Sandra Pihlström
- Folkhälsan Institute of Genetics Helsinki Finland.,Research Program for Clinical and Molecular Metabolism, Faculty of Medicine University of Helsinki Helsinki Finland
| | - Kirsi Määttä
- Folkhälsan Institute of Genetics Helsinki Finland.,Research Program for Clinical and Molecular Metabolism, Faculty of Medicine University of Helsinki Helsinki Finland
| | - Minna Pekkinen
- Folkhälsan Institute of Genetics Helsinki Finland.,Research Program for Clinical and Molecular Metabolism, Faculty of Medicine University of Helsinki Helsinki Finland.,Children's Hospital, University of Helsinki and Helsinki University Hospital Helsinki Finland
| | - Nadja Fratzl-Zelman
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital Vienna Austria.,Vienna Bone and Growth Center Vienna Austria
| | - Outi Mäkitie
- Folkhälsan Institute of Genetics Helsinki Finland.,Research Program for Clinical and Molecular Metabolism, Faculty of Medicine University of Helsinki Helsinki Finland.,Children's Hospital, University of Helsinki and Helsinki University Hospital Helsinki Finland.,Department of Molecular Medicine and Surgery and Center for Molecular Medicine Karolinska Institutet Stockholm Sweden
| | - Markus A Hartmann
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital Vienna Austria.,Vienna Bone and Growth Center Vienna Austria
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44
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Al Kaissi A, Misof BM, Laccone F, Blouin S, Roschger P, Kircher SG, Shboul M, Mindler GT, Girsch W, Ganger R. Clinical Phenotype and Bone Biopsy Characteristics in a Child with Proteus Syndrome. Calcif Tissue Int 2021; 109:586-595. [PMID: 34003338 DOI: 10.1007/s00223-021-00862-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/29/2021] [Indexed: 10/21/2022]
Abstract
Proteus syndrome is a rare genetic disorder, which is characterized by progressive, segmental, or patchy overgrowth of diverse tissues of all germ layers, including the skeleton. Here, we present a 9-year-old girl with a somatic-activating mutation (c.49G > A; p.Glu17Lys) in AKT1 gene in a mosaic status typical for Proteus syndrome. She presented with hemihypertrophy of the right lower limb and a "moccasin" lesion among others. A transiliac bone biopsy was analyzed for bone histology/histomorphometry as well as bone mineralization density distribution (BMDD) and osteocyte lacunae sections (OLS) characteristics based on quantitative backscattered electron imaging. Bone histomorphometry revealed highly increased mineralizing surface (Z-score + 2.3) and mineral apposition rate (Z-score + 19.3), no osteoclasts (Z-score - 2.1), and an increased amount of primary bone in the external cortex. BMDD abnormalities included a decreased mode calcium concentration in cancellous bone (Z-score - 1.7) and an increased percentage of highly mineralized cortical bone area (Z-score + 2.4) compared to reference. OLS characteristics showed several differences compared to reference data; among them, there were the highly increased OLS-porosity, OLS-area, and OLS-perimeter on the external cortex (Z-scores + 6.8, + 4.4 and 5.4, respectively). Our findings suggest that increased bone formation reduced matrix mineralization in cancellous bone while the enhanced amount of primary bone in the external cortex increased the portion of highly mineralized cortical bone and caused OLS-characteristics abnormalities. Our results indicate further that remodeling of primary bone might be disturbed or delayed in agreement with the decreased number of osteoclasts observed in this child with Proteus syndrome.
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Affiliation(s)
- Ali Al Kaissi
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, First Medical Department, Hanusch Hospital, Heinrich Collin Str. 30, 1140, Vienna, Austria
- Department of Pediatric Orthopaedics, Orthopaedic Hospital Speising, Vienna, Austria
| | - Barbara M Misof
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, First Medical Department, Hanusch Hospital, Heinrich Collin Str. 30, 1140, Vienna, Austria.
| | - Franco Laccone
- Center of Pathobiochemistry and Genetics, Institute of Medical Genetics, Medical University of Vienna, Vienna, Austria
| | - Stéphane Blouin
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, First Medical Department, Hanusch Hospital, Heinrich Collin Str. 30, 1140, Vienna, Austria
| | - Paul Roschger
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, First Medical Department, Hanusch Hospital, Heinrich Collin Str. 30, 1140, Vienna, Austria
| | - Susanne G Kircher
- Center of Pathobiochemistry and Genetics, Institute of Medical Chemistry, Medical University of Vienna, Vienna, Austria
| | - Mohammad Shboul
- Department of Medical Laboratory Sciences, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Gabriel T Mindler
- Department of Pediatric Orthopaedics, Orthopaedic Hospital Speising, Vienna, Austria
| | - Werner Girsch
- Department of Plastic and Reconstructive Surgery, Medical University Graz, Graz, Austria
| | - Rudolf Ganger
- Department of Pediatric Orthopaedics, Orthopaedic Hospital Speising, Vienna, Austria
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45
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Medeiros Savi F, Mieszczanek P, Revert S, Wille ML, Bray LJ. A New Automated Histomorphometric MATLAB Algorithm for Immunohistochemistry Analysis Using Whole Slide Imaging. Tissue Eng Part C Methods 2021; 26:462-474. [PMID: 32729382 DOI: 10.1089/ten.tec.2020.0153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
The use of animal models along with the employment of advanced and sophisticated stereological methods for assessing bone quality combined with the use of statistical methods to evaluate the effectiveness of bone therapies has made it possible to investigate the pathways that regulate bone responses to medical devices. Image analysis of histomorphometric measurements remains a time-consuming task, as the image analysis software currently available does not allow for automated image segmentation. Such a feature is usually obtained by machine learning and with software platforms that provide image-processing tools such as MATLAB. In this study, we introduce a new MATLAB algorithm to quantify immunohistochemically stained critical-sized bone defect samples and compare the results with the commonly available Aperio Image Scope Positive Pixel Count (PPC) algorithm. Bland and Altman analysis and Pearson correlation showed that the measurements acquired with the new MATLAB algorithm were in excellent agreement with the measurements obtained with the Aperio PPC algorithm, and no significant differences were found within the histomorphometric measurements. The ability to segment whole slide images, as well as defining the size and the number of regions of interest to be quantified, makes this MATLAB algorithm a potential histomorphometric tool for obtaining more objective, precise, and reproducible quantitative assessments of entire critical-sized bone defect image data sets in an efficient and manageable workflow.
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Affiliation(s)
- Flavia Medeiros Savi
- Centre in Regenerative Medicine, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia.,School of Mechanical, Medical and Process Engineering, Science and Engineering Faculty, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Pawel Mieszczanek
- Centre in Regenerative Medicine, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Sophia Revert
- Centre in Regenerative Medicine, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Marie-Luise Wille
- Centre in Regenerative Medicine, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia.,School of Mechanical, Medical and Process Engineering, Science and Engineering Faculty, Queensland University of Technology, Brisbane, Queensland, Australia.,ARC ITTC for Multiscale 3D Imaging, Modelling, and Manufacturing, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Laura Jane Bray
- Centre in Regenerative Medicine, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia.,School of Mechanical, Medical and Process Engineering, Science and Engineering Faculty, Queensland University of Technology, Brisbane, Queensland, Australia
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46
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Casanova M, Schindeler A, Peacock L, Lee L, Schneider P, Little DG, Müller R. Characterization of the Developing Lacunocanalicular Network During Fracture Repair. JBMR Plus 2021; 5:e10525. [PMID: 34532613 PMCID: PMC8441443 DOI: 10.1002/jbm4.10525] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/23/2021] [Accepted: 06/06/2021] [Indexed: 11/09/2022] Open
Abstract
Fracture repair is a normal physiological response to bone injury. During the process of bony callus formation, a lacunocanalicular network (LCN) is formed de novo that evolves with callus remodeling. Our aim was the longitudinal assessment of the development and evolution of the LCN during fracture repair. To this end, 45 adult wild‐type C57BL/6 mice underwent closed tibial fracture surgery. Fractured and intact contralateral tibias were harvested after 2, 3, and 6 weeks of bone healing (n = 15/group). High‐resolution micro–computed tomography (μCT) and deconvolution microscopy (DV) approaches were applied to quantify lacunar number density from the calluses and intact bone. On histological sections, Goldner's trichrome staining was used to assess lacunar occupancy, fluorescein isothiocyanate staining to visualize the canalicular network, and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate‐biotin nick end labeling (TUNEL) staining to examine osteocyte apoptosis. Analysis of μCT scans showed progressive decreases in mean lacuna volume over time (−27% 2–3 weeks; −13% 3–6 weeks). Lacunar number density increased considerably between 2 and 3 weeks (+156%). Correlation analysis was performed, showing a positive linear relationship between canalicular number density and trabecular thickness (R2 = 0.56, p < 0.001) and an inverse relationship between mean lacuna volume and trabecular thickness (R2 = 0.57, p < 0.001). Histology showed increases in canalicular number density over time (+22% 2–3 weeks, +51% 3–6 weeks). Lacunar occupancy in new bone of the callus was high (>90%), but the old cortical bone within the fracture site appeared necrotic as it underwent resorption. In conclusion, our data shows a progressive increase in the complexity of the LCN over time during fracture healing and demonstrates that this network is initiated during the early stages of repair. Further studies are needed to address the functional importance of osteocytes in bone healing, particularly in detecting and translating the effects of micromotion in the fracture. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
| | - Aaron Schindeler
- Orthopaedic Research & Biotechnology The Children's Hospital at Westmead Westmead Australia.,Discipline of Child and Adolescent Health University of Sydney Camperdown Australia
| | - Lauren Peacock
- Orthopaedic Research & Biotechnology The Children's Hospital at Westmead Westmead Australia
| | - Lucinda Lee
- Orthopaedic Research & Biotechnology The Children's Hospital at Westmead Westmead Australia.,Discipline of Child and Adolescent Health University of Sydney Camperdown Australia
| | - Philipp Schneider
- Institute for Biomechanics ETH Zurich Zurich Switzerland.,Bioengineering Science Research Group, Faculty of Engineering and Physical Sciences University of Southampton Southampton UK.,High-Performance Vision Systems, Center for Vision, Automation & Control Austrian Institute of Technology (AIT) Vienna Austria
| | - David G Little
- Orthopaedic Research & Biotechnology The Children's Hospital at Westmead Westmead Australia.,Discipline of Child and Adolescent Health University of Sydney Camperdown Australia
| | - Ralph Müller
- Institute for Biomechanics ETH Zurich Zurich Switzerland
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47
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Mahr C, Dworzak A, Schowalter M, Oezaslan M, Rosenauer A. Quantitative 3D Characterization of Nanoporous Gold Nanoparticles by Transmission Electron Microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2021; 27:678-686. [PMID: 34085625 DOI: 10.1017/s1431927621000519] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Quantitative structural characterization of nanomaterials is important to tailor their functional properties. Corrosion of AgAu-alloy nanoparticles (NPs) results in porous structures, making them interesting for applications especially in the fields of catalysis and surface-enhanced Raman spectroscopy. For the present report, structures of dealloyed NPs were reconstructed three-dimensionally using scanning transmission electron microscopy tomography. These reconstructions were evaluated quantitatively, revealing structural information such as pore size, porosity, specific surface area, and tortuosity. Results show significant differences compared to the structure of dealloyed bulk samples and can be used as input for simulations of diffusion or mass transport processes, for example, in catalytic applications.
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Affiliation(s)
- Christoph Mahr
- Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359Bremen, Germany
- MAPEX Center for Materials and Processes, University of Bremen, Bibliothekstr. 1, 28359Bremen, Germany
| | - Alexandra Dworzak
- Technical Electrocatalysis Laboratory, Institute of Technical Chemistry, Technical University of Braunschweig, Franz-Liszt-Str. 35a, 38106Braunschweig, Germany
- Institute of Chemistry, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26129Oldenburg, Germany
| | - Marco Schowalter
- Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359Bremen, Germany
- MAPEX Center for Materials and Processes, University of Bremen, Bibliothekstr. 1, 28359Bremen, Germany
| | - Mehtap Oezaslan
- Technical Electrocatalysis Laboratory, Institute of Technical Chemistry, Technical University of Braunschweig, Franz-Liszt-Str. 35a, 38106Braunschweig, Germany
- Institute of Chemistry, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26129Oldenburg, Germany
| | - Andreas Rosenauer
- Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359Bremen, Germany
- MAPEX Center for Materials and Processes, University of Bremen, Bibliothekstr. 1, 28359Bremen, Germany
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48
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Li S, Pan R, Gupta A, Xu S, Fang Y, Huang H. Predicting the risk of rupture for vertebral aneurysm based on geometric features of blood vessels. ROYAL SOCIETY OPEN SCIENCE 2021; 8:210392. [PMID: 34430044 PMCID: PMC8355691 DOI: 10.1098/rsos.210392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
A significant proportion of the adult population worldwide suffers from cerebral aneurysms. If left untreated, aneurysms may rupture and lead to fatal massive internal bleeding. On the other hand, treatment of aneurysms also involve significant risks. It is desirable, therefore, to have an objective tool that can be used to predict the risk of rupture and assist in surgical decision for operating on the aneurysms. Currently, such decisions are made mostly based on medical expertise of the healthcare team. In this paper, we investigate the possibility of using machine learning algorithms to predict rupture risk of vertebral artery fusiform aneurysms based on geometric features of the blood vessels surrounding but excluding the aneurysm. For each of the aneurysm images (12 ruptured and 25 unruptured), the vessel is segmented into distal and proximal parts by cross-sectional area and 382 non-aneurysm-related geometric features extracted. The decision tree model using two of the features (standard deviation of eccentricity of proximal vessel, and diameter at the distal endpoint) achieved 83.8% classification accuracy. Additionally, with support vector machine and logistic regression, we also achieved 83.8% accuracy with another set of two features (ratio of mean curvature between distal and proximal parts, and diameter at the distal endpoint). Combining the aforementioned three features with integration of curvature of proximal vessel and also ratio of mean cross-sectional area between distal and proximal parts, these models achieve an impressive 94.6% accuracy. These results strongly suggest the usefulness of geometric features in predicting the risk of rupture.
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Affiliation(s)
- Shixuan Li
- Department of Computer Science, University of Toronto, Toronto, Ontario, Canada
| | - Ruiqi Pan
- Department of Computer Science, McCormick School of Engineering, Northwestern University, Evanston, IL, USA
| | - Arvind Gupta
- Department of Computer Science, University of Toronto, Toronto, Ontario, Canada
| | - Shixin Xu
- Data Science Research Center, Zu Chongzhi Center for Mathematics and Computational Sciences, Duke Kunshan University, Kunshan, Jiangsu, People’s Republic of China
| | - Yibin Fang
- Department of Neurosurgery, Changhai Hospital, Shanghai, China
| | - Huaxiong Huang
- Research Centre for Mathematics, Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai, People’s Republic of China
- BNU-HKBU United International College, Zhuhai, People’s Republic of China
- Department of Mathematics and Statistics, York University, Toronto, Ontario, Canada
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49
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Lehder EF, Ashcroft IA, Wildman RD, Ruiz-Cantu LA, Maskery I. A multiscale optimisation method for bone growth scaffolds based on triply periodic minimal surfaces. Biomech Model Mechanobiol 2021; 20:2085-2096. [PMID: 34318358 PMCID: PMC8595174 DOI: 10.1007/s10237-021-01496-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 07/10/2021] [Indexed: 11/09/2022]
Abstract
Tissue engineered bone scaffolds are potential alternatives to bone allografts and autografts. Porous scaffolds based on triply periodic minimal surfaces (TPMS) are good candidates for tissue growth because they offer high surface-to-volume ratio, have tailorable stiffness, and can be easily fabricated by additive manufacturing. However, the range of TPMS scaffold types is extensive, and it is not yet clear which type provides the fastest cell or tissue growth while being sufficiently stiff to act as a bone graft. Nor is there currently an established methodology for TPMS bone scaffold design which can be quickly adopted by medical designers or biologists designing implants. In this study, we examine six TPMS scaffold types for use as tissue growth scaffolds and propose a general methodology to optimise their geometry. At the macro-scale, the optimisation routine ensures a scaffold stiffness within suitable limits for bone, while at the micro-scale it maximises the cell growth rate. The optimisation procedure also ensures the scaffold pores are of sufficient diameter to allow oxygen and nutrient delivery via capillaries. Of the examined TPMS structures, the Lidinoid and Split P cell types provide the greatest cell growth rates and are therefore the best candidates for bone scaffolds.
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Affiliation(s)
- E F Lehder
- Centre for Additive Manufacturing, Faculty of Engineering, The University of Nottingham, Nottingham, NG7 2RD, UK
| | - I A Ashcroft
- Centre for Additive Manufacturing, Faculty of Engineering, The University of Nottingham, Nottingham, NG7 2RD, UK
| | - R D Wildman
- Centre for Additive Manufacturing, Faculty of Engineering, The University of Nottingham, Nottingham, NG7 2RD, UK
| | - L A Ruiz-Cantu
- Centre for Additive Manufacturing, Faculty of Engineering, The University of Nottingham, Nottingham, NG7 2RD, UK
| | - I Maskery
- Centre for Additive Manufacturing, Faculty of Engineering, The University of Nottingham, Nottingham, NG7 2RD, UK.
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50
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Automated three-dimensional vessel reconstruction based on deep segmentation and bi-plane angiographic projections. Comput Med Imaging Graph 2021; 92:101956. [PMID: 34315034 DOI: 10.1016/j.compmedimag.2021.101956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 08/18/2020] [Accepted: 07/16/2021] [Indexed: 11/23/2022]
Abstract
Automated three-dimensional (3D) blood vessel reconstruction to improve vascular diagnosis and therapeutics is a challenging task in which the real-time implementation of automatic segmentation and specific vessel tracking for matching artery sequences is essential. Recently, a deep learning-based segmentation technique has been proposed; however, existing state-of-the-art deep architectures exhibit reduced performance when they are employed using real in-vivo imaging because of serious issues such as low contrast and noise contamination of the X-ray images. To overcome these limitations, we propose a novel methodology composed of the de-haze image enhancement technique as pre-processing and multi-level thresholding as post-processing to be applied to the lightweight multi-resolution U-shaped architecture. Specifically, (1) bi-plane two-dimensional (2D) vessel images were extracted simultaneously using the deep architecture, (2) skeletons of the vessels were computed via a morphology operation, (3) the corresponding skeleton structure between image sequences was matched using the shape-context technique, and (4) the 3D centerline was reconstructed using stereo geometry. The method was validated using both in-vivo and in-vitro models. The results show that the proposed technique could improve the segmentation quality, reduce computation time, and reconstruct the 3D skeleton automatically. The algorithm accurately reconstructed the phantom model and the real mouse vessel in 3D in 2 s. Our proposed technique has the potential to allow therapeutic micro-agent navigation in clinical practice, thereby providing the 3D position and orientation of the vessel.
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