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Sugita S, Kawai R, Ujihara Y, Nakamura M. Stress fiber strain is zero in normal aortic smooth muscle, elevated in hypertensive stretch, and minimal in wall thickening rats. Sci Rep 2024; 14:29731. [PMID: 39613822 PMCID: PMC11606938 DOI: 10.1038/s41598-024-81229-w] [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: 07/15/2024] [Accepted: 11/25/2024] [Indexed: 12/01/2024] Open
Abstract
Hypertension causes aortic wall thickening until the original wall stress is restored. We hypothesized that this regulation involves stress fiber (SF) tension transmission to the nucleus in smooth muscle cells (SMCs) and investigated the strain in the SF direction as a condition required for this transmission. Thoracic aortas from Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHRs) were examined. SFs in aortic SMCs were fluorescently labeled and observed under a confocal microscope while stretched along the circumferential (θ) axis. Three conditions were studied: WKY physiological (WKYphys; blood pressure changes from diastolic to systolic for WKY), high-strain state (WKYhigh; diastolic to hypertensive level for WKY simulating initial hypertension), and SHR physiological (SHRphys; diastolic to systolic for SHR simulating after wall-thickening). SF strain and direction were measured. The SF inclination angle from the θ axis was 18° ± 3° in WKYphys, 13° ± 2° in WKYhigh, and 20° ± 1° in SHRphys. SF strain was 0.01 ± 0.02 in WKYphys, 0.20 ± 0.04 in WKYhigh, and 0.02 ± 0.02 SHRphys. SF strain was minimal in WKYphys, significantly increased in WKYhigh, and reduced to approximately zero in SHRphys. These findings support SFs function as mechanosensors in response to hypertension.
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Affiliation(s)
- Shukei Sugita
- Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Gokiso-Cho, Showa-Ku, Nagoya, 466-8555, Japan.
- Center of Biomedical Physics and Information Technology, Nagoya Institute of Technology, Gokiso-Cho, Showa-Ku, Nagoya, Japan.
| | - Rintaro Kawai
- Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Gokiso-Cho, Showa-Ku, Nagoya, 466-8555, Japan
| | - Yoshihiro Ujihara
- Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Gokiso-Cho, Showa-Ku, Nagoya, 466-8555, Japan
| | - Masanori Nakamura
- Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Gokiso-Cho, Showa-Ku, Nagoya, 466-8555, Japan
- Center of Biomedical Physics and Information Technology, Nagoya Institute of Technology, Gokiso-Cho, Showa-Ku, Nagoya, Japan
- Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology, Gokiso-Cho, Showa-Ku, Nagoya, Japan
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2
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Saini K, Cho S, Tewari M, Jalil AR, Wang M, Kasznel AJ, Yamamoto K, Chenoweth DM, Discher DE. Pan-tissue scaling of stiffness versus fibrillar collagen reflects contractility-driven strain that inhibits fibril degradation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.27.559759. [PMID: 37808742 PMCID: PMC10557712 DOI: 10.1101/2023.09.27.559759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Polymer network properties such as stiffness often exhibit characteristic power laws in polymer density and other parameters. However, it remains unclear whether diverse animal tissues, composed of many distinct polymers, exhibit such scaling. Here, we examined many diverse tissues from adult mouse and embryonic chick to determine if stiffness ( E tissue ) follows a power law in relation to the most abundant animal protein, Collagen-I, even with molecular perturbations. We quantified fibrillar collagen in intact tissue by second harmonic generation (SHG) imaging and from tissue extracts by mass spectrometry (MS), and collagenase-mediated decreases were also tracked. Pan-tissue power laws for tissue stiffness versus Collagen-I levels measured by SHG or MS exhibit sub-linear scaling that aligns with results from cellularized gels of Collagen-I but not acellular gels. Inhibition of cellular myosin-II based contraction fits the scaling, and combination with inhibitors of matrix metalloproteinases (MMPs) show collagenase activity is strain - not stress- suppressed in tissues, consistent with past studies of gels and fibrils. Beating embryonic hearts and tendons, which differ in both collagen levels and stiffness by >1000-fold, similarly suppressed collagenases at physiological strains of ∼5%, with fiber-orientation regulating degradation. Scaling of E tissue based on 'use-it-or-lose-it' kinetics provides insight into scaling of organ size, microgravity effects, and regeneration processes while suggesting contractility-driven therapeutics.
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3
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Sherlock B, Chen J, Mansfield J, Green E, Winlove C. Biophotonic tools for probing extracellular matrix mechanics. Matrix Biol Plus 2021; 12:100093. [PMID: 34934939 PMCID: PMC8661043 DOI: 10.1016/j.mbplus.2021.100093] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 11/07/2021] [Accepted: 11/11/2021] [Indexed: 12/11/2022] Open
Abstract
The complex, hierarchical and heterogeneous biomechanics of the extracellular matrix (ECM) are central to the health of multicellular organisms. Characterising the distribution, dynamics and above all else origins of ECM biomechanics are challenges that have captivated researchers for decades. Recently, a suite of biophotonics techniques have emerged as powerful new tools to investigate ECM biomechanics. In this mini-review, we discuss how the non-destructive, sub-micron resolution imaging capabilities of Raman spectroscopy and nonlinear microscopy are being used to interrogate the biomechanics of thick, living tissues. These high speed, label-free techniques are implemented during mechanical testing, providing unprecedented insight into the compositional and structural response of the ECM to changes in the mechanical environment.
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Affiliation(s)
- B.E. Sherlock
- College of Medicine and Health, University of Exeter, Exeter EX1 2LU, United Kingdom
| | - J. Chen
- College of Engineering, Mathematical and Physical Sciences, University of Exeter, Exeter EX4 4QF, United Kingdom
| | - J.C. Mansfield
- College of Engineering, Mathematical and Physical Sciences, University of Exeter, Exeter EX4 4QF, United Kingdom
| | - E. Green
- College of Engineering, Mathematical and Physical Sciences, University of Exeter, Exeter EX4 4QF, United Kingdom
| | - C.P. Winlove
- College of Engineering, Mathematical and Physical Sciences, University of Exeter, Exeter EX4 4QF, United Kingdom
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4
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Sugita S, Mizuno N, Ujihara Y, Nakamura M. Stress fibers of the aortic smooth muscle cells in tissues do not align with the principal strain direction during intraluminal pressurization. Biomech Model Mechanobiol 2021; 20:1003-1011. [PMID: 33515313 PMCID: PMC8154808 DOI: 10.1007/s10237-021-01427-7] [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] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 01/19/2021] [Indexed: 11/13/2022]
Abstract
Stress fibers (SFs) in cells transmit external forces to cell nuclei, altering the DNA structure, gene expression, and cell activity. To determine whether SFs are involved in mechanosignal transduction upon intraluminal pressure, this study investigated the SF direction in smooth muscle cells (SMCs) in aortic tissue and strain in the SF direction. Aortic tissues were fixed under physiological pressure of 120 mmHg. First, we observed fluorescently labeled SFs using two-photon microscopy. It was revealed that SFs in the same smooth muscle layers were aligned in almost the same direction, and the absolute value of the alignment angle from the circumferential direction was 16.8° ± 5.2° (n = 96, mean ± SD). Second, we quantified the strain field in the aortic tissue in reference to photo-bleached markers. It was found in the radial-circumferential plane that the largest strain direction was − 21.3° ± 11.1°, and the zero normal strain direction was 28.1° ± 10.2°. Thus, the SFs in aortic SMCs were not in line with neither the largest strain direction nor the zero strain direction, although their orientation was relatively close to the zero strain direction. These results suggest that SFs in aortic SMCs undergo stretch, but not maximal and transmit the force to nuclei under intraluminal pressure.
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Affiliation(s)
- Shukei Sugita
- Biomechanics Laboratory, Department of Electrical and Mechanical Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan. .,Center of Biomedical Physics and Information Technology, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Japan.
| | - Naoto Mizuno
- Biomechanics Laboratory, Department of Electrical and Mechanical Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan
| | - Yoshihiro Ujihara
- Biomechanics Laboratory, Department of Electrical and Mechanical Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan
| | - Masanori Nakamura
- Biomechanics Laboratory, Department of Electrical and Mechanical Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan.,Center of Biomedical Physics and Information Technology, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Japan.,Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Japan
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5
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Sednieva Y, Viste A, Naaim A, Bruyère-Garnier K, Gras LL. Strain Assessment of Deep Fascia of the Thigh During Leg Movement: An in situ Study. Front Bioeng Biotechnol 2020; 8:750. [PMID: 32850692 PMCID: PMC7403494 DOI: 10.3389/fbioe.2020.00750] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 06/11/2020] [Indexed: 11/30/2022] Open
Abstract
Fascia is a fibrous connective tissue present all over the body. At the lower limb level, the deep fascia that is overlying muscles of the outer thigh and sheathing them (fascia lata) is involved in various pathologies. However, the understanding and quantification of the mechanisms involved in these sheathing effects are still unclear. The aim of this study is to observe and quantify the strain field of the fascia lata, including the iliotibial tract (ITT), during a passive movement of the knee. Three fresh postmortem human subjects were studied. To measure hip and knee angles during knee flexion-extension, passive movements from 0° to around 120° were recorded with a motion analysis system and strain fields of the fascia were acquired using digital image correlation. Strains were computed for three areas of the fascia lata: anterior fascia, lateral fascia, and ITT. Mean principal strains showed different strain mechanisms depending on location on the fascia and knee angle. For the ITT, two strain mechanisms were observed depending on knee movement: compression is observed when the knee is extended relative to the reference position of 47°, however, tension and pure shear can be observed when the knee is flexed. For the anterior and lateral fascia, in most cases, minor strain is higher than major strain in absolute value, suggesting high tissue compression probably due to microstructural fiber rearrangements. This in situ study is the first attempt to quantify the superficial strain field of fascia lata during passive leg movement. The study presents some limitations but provides a step in understanding strain mechanism of the fascia lata during passive knee movement.
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Affiliation(s)
- Yuliia Sednieva
- Univ Lyon, Université Claude Bernard Lyon 1, Univ Gustave Eiffel, IFSTTAR, LBMC UMR_T9406, Lyon, France
| | - Anthony Viste
- Univ Lyon, Université Claude Bernard Lyon 1, Univ Gustave Eiffel, IFSTTAR, LBMC UMR_T9406, Lyon, France
- Hospices Civils de Lyon, Hôpital Lyon Sud, Chirurgie Orthopédique, Pierre-Bénite, France
| | - Alexandre Naaim
- Univ Lyon, Université Claude Bernard Lyon 1, Univ Gustave Eiffel, IFSTTAR, LBMC UMR_T9406, Lyon, France
| | - Karine Bruyère-Garnier
- Univ Lyon, Université Claude Bernard Lyon 1, Univ Gustave Eiffel, IFSTTAR, LBMC UMR_T9406, Lyon, France
| | - Laure-Lise Gras
- Univ Lyon, Université Claude Bernard Lyon 1, Univ Gustave Eiffel, IFSTTAR, LBMC UMR_T9406, Lyon, France
- *Correspondence: Laure-Lise Gras,
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6
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Sugita S, Kato M, Wataru F, Nakamura M. Three-dimensional analysis of the thoracic aorta microscopic deformation during intraluminal pressurization. Biomech Model Mechanobiol 2019; 19:147-157. [PMID: 31297645 PMCID: PMC7005079 DOI: 10.1007/s10237-019-01201-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 07/06/2019] [Indexed: 12/16/2022]
Abstract
The aorta is composed of various constituents with different mechanical properties. This heterogeneous structure implies non-uniform deformation in the aorta, which could affect local cell functions. The present study investigates 3D strains of the aorta at a cell scale induced by intraluminal pressurization. After resected mouse, thoracic aortas were stretched to their in vivo length, and the aortas were pressurized at 15, 40, 80, 120, and 160 mmHg. Images of autofluorescent light of elastin were captured under a two-photon microscope. From the movement of markers in elastic laminas (ELs) created by photo-bleaching, 3D strains (εθθ, εzz, εrr, εrθ, εrz, εθz) between two neighboring ELs in the circumferential (θ), longitudinal (z), and radial (r) directions with reference to the dimensions at 15 mmHg were calculated. The results demonstrated that the average of shear strain εrθ was almost 0 in a physiological pressure range (from 80 to 120 mmHg) with an absolute value |εrθ| changing approximately by 5%. This indicates that ELs experience radial–circumferential shear at the cell scale, but not at the whole tissue scale. The normal strains in the circumferential εθθ and longitudinal direction εzz were positive but that in the radial direction εrr was almost 0, which demonstrates that aortic tissue is not an incompressible material. The first principal direction in the radial–circumferential plane was 29° ± 13° from the circumferential direction. We show that the aorta is not simply stretched in the circumferential direction during pressurization and that cells in the aorta undergo complex deformations by nature.
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Affiliation(s)
- Shukei Sugita
- Biomechanics Laboratory, Department of Electrical and Mechanical Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan.
| | - Masaya Kato
- Biomechanics Laboratory, Department of Electrical and Mechanical Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan
| | - Fukui Wataru
- Biomechanics Laboratory, Department of Electrical and Mechanical Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan
| | - Masanori Nakamura
- Biomechanics Laboratory, Department of Electrical and Mechanical Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan
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7
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Zündel M, Ehret AE, Mazza E. The multiscale stiffness of electrospun substrates and aspects of their mechanical biocompatibility. Acta Biomater 2019; 84:146-158. [PMID: 30447336 DOI: 10.1016/j.actbio.2018.11.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 10/10/2018] [Accepted: 11/07/2018] [Indexed: 02/04/2023]
Abstract
In contrast to homogeneous materials, the mechanical properties of fibrous substrates depend on the probing lengthscale. This suggests that cells feel very different mechanical cues than expected from the macroscale characterisation of the substrate materials. By means of multiscale computational analyses we study here the mechanical environment of cells adhering to typical electrospun networks used in biomedical applications, with comparable macroscopic stiffness but different fibre diameters. The stiffness evaluated at the level of focal adhesions varies significantly, and the overall magnitude is strongly affected by the fibre diameter. The microscopic stiffness evaluated at cell scale depends substantially on the network topology and is about one order of magnitude lower than the macroscopic stiffness of the substrate, and two to three orders of magnitude below the fibres' elastic modulus. Moreover, the translation of stiffness over the scales is modulated by global deformations of the scaffold. In particular, uniaxial or biaxial stretching of the substrate induces nonlinear microscopic stiffening. Finally, although electrospun networks allow long-range transmission of cell-induced deformations, the comparison between the range of forces measured in cell traction force microscopy and those required to markedly deform typical electrospun networks reveals an order of magnitude difference, suggesting that these scaffolds provide a rather rigid environment for cells. All these results underline that the achievement of mechanical biocompatibility at all relevant lengthscales, and over the whole range of physiological loading states is extremely challenging. At the same time, the study shows that the diameter, length and curvature of fibre segments might be tunable towards achieving this goal. STATEMENT OF SIGNIFICANCE: Electrospun fabrics have growing use as substrates and scaffolds in tissue engineering and other biomedical applications. Based on multiscale computational analyses, this study shows that substrates of comparable macroscopic stiffness can provide tremendously different mechanical micro-environments, and that cells adhering to fibrous substrates may thus experience by orders of magnitude different mechanical cues than it would be expected from macroscale material characterisation. The simulations further reveal that the transfer of stiffness over the length scales changes with macroscopic deformation, and identify some key parameters that govern the transfer ratio. We believe that such refined understanding of the multiscale aspects of mechanical biocompatibility is key to the development of successful scaffold materials.
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Affiliation(s)
- Manuel Zündel
- ETH Zürich, Institute for Mechanical Systems, 8092 Zürich, Switzerland
| | - Alexander E Ehret
- ETH Zürich, Institute for Mechanical Systems, 8092 Zürich, Switzerland; Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland
| | - Edoardo Mazza
- ETH Zürich, Institute for Mechanical Systems, 8092 Zürich, Switzerland; Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland.
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8
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Croce AC, Ferrigno A, Bottiroli G, Vairetti M. Autofluorescence-based optical biopsy: An effective diagnostic tool in hepatology. Liver Int 2018; 38:1160-1174. [PMID: 29624848 DOI: 10.1111/liv.13753] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/27/2018] [Indexed: 12/15/2022]
Abstract
Autofluorescence emission of liver tissue depends on the presence of endogenous biomolecules able to fluoresce under suitable light excitation. Overall autofluorescence emission contains much information of diagnostic value because it is the sum of individual autofluorescence contributions from fluorophores involved in metabolism, for example, NAD(P)H, flavins, lipofuscins, retinoids, porphyrins, bilirubin and lipids, or in structural architecture, for example, fibrous proteins, in close relationship with normal, altered or diseased conditions of the liver. Since the 1950s, hepatocytes and liver have been historical models to study NAD(P)H and flavins as in situ, real-time autofluorescence biomarkers of energy metabolism and redox state. Later investigations designed to monitor organ responses to ischaemia/reperfusion were able to predict the risk of dysfunction in surgery and transplantation or support the development of procedures to ameliorate the liver outcome. Subsequently, fluorescent fatty acids, lipofuscin-like lipopigments and collagen were characterized as optical biomarkers of liver steatosis, oxidative stress damage, fibrosis and disease progression. Currently, serum AF is being investigated to improve non-invasive optical diagnosis of liver disease. Validation of endogenous fluorophores and in situ discrimination of cancerous from non-cancerous tissue belong to the few studies on liver in human subjects. These reports along with other optical techniques and the huge work performed on animal models suggest many optically based applications in hepatology. Optical diagnosis is currently offering beneficial outcomes in clinical fields ranging from the respiratory and gastrointestinal tracts, to dermatology and ophthalmology. Accordingly, this review aims to promote an effective bench to bedside transfer in hepatology.
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Affiliation(s)
- Anna Cleta Croce
- Institute of Molecular Genetics, Italian National Research Council (CNR), Pavia, Italy.,Department of Biology & Biotechnology, University of Pavia, Pavia, Italy
| | - Andrea Ferrigno
- Internal Medicine and Therapy Department, University of Pavia, Pavia, Italy
| | - Giovanni Bottiroli
- Institute of Molecular Genetics, Italian National Research Council (CNR), Pavia, Italy.,Department of Biology & Biotechnology, University of Pavia, Pavia, Italy
| | - Mariapia Vairetti
- Internal Medicine and Therapy Department, University of Pavia, Pavia, Italy
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9
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Bircher K, Ehret AE, Mazza E. Microstructure based prediction of the deformation behavior of soft collagenous membranes. SOFT MATTER 2017; 13:5107-5116. [PMID: 28492654 DOI: 10.1039/c7sm00101k] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The response of human amnion (HA) and bovine Glisson's capsule (GC) to uniaxial and biaxial tensile loading is analyzed on tissue (∼mm) and collagen fiber (∼μm) length scales. The mechanical behavior of the membranes is rationalized based on a discrete fiber network model that relates model parameters with microstructural features of the tissues. Parameters were first determined for GC based on the quantity and organization of collagen fibers in the tissue. Next, parameters for HA were defined by comparing the microstructures of the two membranes, which differ in fiber organization in that collagen forms μm-thick fiber bundles in GC while 50 nm-thin fibrils constitute the network in HA. The flexural behavior of these structures is phenomenologically represented in the model, indicating that shear forces are transmitted through fibrils within GC bundles, but to a much lesser extent than in a corresponding solid cross section. The model provides excellent predictions of the uniaxial and biaxial mechanical response, as well as of the progressive reorientation of fibers associated with uniaxial loading. The results are particularly relevant since model parameters were not obtained through a fitting procedure of the tissue's tension-stretch curve. Furthermore, simulations of representative in vivo deformation states indicated that a large part of the fibers are expected to be un-crimped under physiological loading conditions. Thus, the crimped shape of collagen fibers in the initial test configuration, and typically observed in histological analyses, might be a consequence of the contraction occurring when membranes are extracted from their environment in the body.
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Affiliation(s)
- Kevin Bircher
- Institute for Mechanical Systems, ETH Zurich, 8092 Zurich, Switzerland.
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10
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Jayyosi C, Affagard JS, Ducourthial G, Bonod-Bidaud C, Lynch B, Bancelin S, Ruggiero F, Schanne-Klein MC, Allain JM, Bruyère-Garnier K, Coret M. Affine kinematics in planar fibrous connective tissues: an experimental investigation. Biomech Model Mechanobiol 2017; 16:1459-1473. [DOI: 10.1007/s10237-017-0899-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 03/15/2017] [Indexed: 02/07/2023]
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11
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Wang H, Liang X, Gravot G, Thorling CA, Crawford DHG, Xu ZP, Liu X, Roberts MS. Visualizing liver anatomy, physiology and pharmacology using multiphoton microscopy. JOURNAL OF BIOPHOTONICS 2017; 10:46-60. [PMID: 27312349 DOI: 10.1002/jbio.201600083] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 05/18/2016] [Indexed: 05/09/2023]
Abstract
Multiphoton microscopy (MPM) has become increasingly popular and widely used in both basic and clinical liver studies over the past few years. This technology provides insights into deep live tissues with less photobleaching and phototoxicity, which helps us to better understand the cellular morphology, microenvironment, immune responses and spatiotemporal dynamics of drugs and therapeutic cells in the healthy and diseased liver. This review summarizes the principles, opportunities, applications and limitations of MPM in hepatology. A key emphasis is on the use of fluorescence lifetime imaging (FLIM) to add additional quantification and specificity to the detection of endogenous fluorescent species in the liver as well as exogenous molecules and nanoparticles that are applied to the liver in vivo. We anticipate that in the near future MPM-FLIM will advance our understanding of the cellular and molecular mechanisms of liver diseases, and will be evaluated from bench to bedside, leading to real-time histology of human liver diseases.
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Affiliation(s)
- Haolu Wang
- Therapeutics Research Centre, School of Medicine, The University of Queensland, Princess Alexandra Hospital, Woolloongabba, QLD 4102, Australia
| | - Xiaowen Liang
- Therapeutics Research Centre, School of Medicine, The University of Queensland, Princess Alexandra Hospital, Woolloongabba, QLD 4102, Australia
| | - Germain Gravot
- Department of Pharmacy, University of Rennes 1, Ille-et-Vilaine, Rennes, 35043, France
| | - Camilla A Thorling
- Therapeutics Research Centre, School of Medicine, The University of Queensland, Princess Alexandra Hospital, Woolloongabba, QLD 4102, Australia
| | - Darrell H G Crawford
- School of Medicine, The University of Queensland, Gallipoli Medical Research Foundation, Greenslopes Private Hospital, Greenslopes, QLD 4120, Australia
| | - Zhi Ping Xu
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Xin Liu
- Therapeutics Research Centre, School of Medicine, The University of Queensland, Princess Alexandra Hospital, Woolloongabba, QLD 4102, Australia
| | - Michael S Roberts
- Therapeutics Research Centre, School of Medicine, The University of Queensland, Princess Alexandra Hospital, Woolloongabba, QLD 4102, Australia
- School of Pharmacy and Medical Science, University of South Australia, Adelaide, SA 5001, Australia
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12
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Bircher K, Ehret AE, Mazza E. Mechanical Characteristics of Bovine Glisson's Capsule as a Model Tissue for Soft Collagenous Membranes. J Biomech Eng 2016; 138:2530163. [DOI: 10.1115/1.4033917] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Indexed: 01/19/2023]
Abstract
An extensive multiaxial experimental campaign on the monotonic, time- and history-dependent mechanical response of bovine Glisson's capsule (GC) is presented. Reproducible characteristics were observed such as J-shaped curves in uniaxial and biaxial configurations, large lateral contraction, cyclic tension softening, large tension relaxation, and moderate creep strain accumulation. The substantial influence of the reference state selection on the kinematic response and the tension versus stretch curves is demonstrated and discussed. The parameters of a large-strain viscoelastic constitutive model were determined based on the data of uniaxial tension relaxation experiments. The model is shown to well predict the uniaxial and biaxial viscoelastic responses in all other configurations. GC, the corresponding model, and the experimental protocols are proposed as a useful basis for future studies on the relation between microstructure and tissue functionality and on the factors influencing the mechanical response of soft collagenous membranes.
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Affiliation(s)
- Kevin Bircher
- Institute for Mechanical Systems, ETH Zurich, Zurich 8092, Switzerland e-mail:
| | - Alexander E. Ehret
- Institute for Mechanical Systems, ETH Zurich, Zurich 8092, Switzerland; Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland e-mail:
| | - Edoardo Mazza
- Institute for Mechanical Systems, ETH Zurich, Zurich 8092, Switzerland; Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland e-mail:
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13
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Jayyosi C, Coret M, Bruyère-Garnier K. Characterizing liver capsule microstructure via in situ bulge test coupled with multiphoton imaging. J Mech Behav Biomed Mater 2016; 54:229-43. [DOI: 10.1016/j.jmbbm.2015.09.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 09/23/2015] [Accepted: 09/24/2015] [Indexed: 10/22/2022]
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14
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Mauri A, Ehret AE, Perrini M, Maake C, Ochsenbein-Kölble N, Ehrbar M, Oyen ML, Mazza E. Deformation mechanisms of human amnion: Quantitative studies based on second harmonic generation microscopy. J Biomech 2015; 48:1606-13. [PMID: 25805698 DOI: 10.1016/j.jbiomech.2015.01.045] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 01/31/2015] [Indexed: 11/15/2022]
Abstract
Multiphoton microscopy has proven to be a versatile tool to analyze the three-dimensional microstructure of the fetal membrane and the mechanisms of deformation on the length scale of cells and the collagen network. In the present contribution, dedicated microscopic tools for in situ mechanical characterization of tissue under applied mechanical loads and the related methods for data interpretation are presented with emphasis on new stepwise monotonic uniaxial experiments. The resulting microscopic parameters are consistent with previous ones quantified for cyclic and relaxation tests, underlining the reliability of these techniques. The thickness reduction and the substantial alignment of collagen fiber bundles in the compact and fibroblast layer starting at very small loads are highlighted, which challenges the definition of a reference configuration in terms of a force threshold. The findings presented in this paper intend to inform the development of models towards a better understanding of fetal membrane deformation and failure, and thus of related problems in obstetrics and other clinical conditions.
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Affiliation(s)
- Arabella Mauri
- Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland.
| | - Alexander E Ehret
- Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Michela Perrini
- Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland; Department of Obstetrics, University Hospital Zürich, 8091 Zurich, Switzerland
| | - Caroline Maake
- Institute of Anatomy, University of Zurich, 8057 Zurich, Switzerland
| | | | - Martin Ehrbar
- Department of Obstetrics, University Hospital Zürich, 8091 Zurich, Switzerland
| | - Michelle L Oyen
- Cambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ, UK
| | - Edoardo Mazza
- Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland; Swiss Federal Laboratories for Materials Science and Technology, EMPA, 8600 Dübendorf, Switzerland
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15
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Lihachev A, Derjabo A, Ferulova I, Lange M, Lihacova I, Spigulis J. Autofluorescence imaging of basal cell carcinoma by smartphone RGB camera. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:120502. [PMID: 26662298 DOI: 10.1117/1.jbo.20.12.120502] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 11/12/2015] [Indexed: 05/16/2023]
Abstract
The feasibility of smartphones for in vivo skin autofluorescence imaging has been investigated. Filtered autofluorescence images from the same tissue area were periodically captured by a smartphone RGB camera with subsequent detection of fluorescence intensity decreasing at each image pixel for further imaging the planar distribution of those values. The proposed methodology was tested clinically with 13 basal cell carcinoma and 1 atypical nevus. Several clinical cases and potential future applications of the smartphone-based technique are discussed.
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Affiliation(s)
- Alexey Lihachev
- University of Latvia, Institute of Atomic Physics and Spectroscopy, Biophotonics Laboratory, Raina Boulevard 19, Riga LV-1586, Latvia
| | - Alexander Derjabo
- Riga East University Hospital, Oncology Centre of Latvia, Hipokrata Street 4, Riga LV-1079, Latvia
| | - Inesa Ferulova
- University of Latvia, Institute of Atomic Physics and Spectroscopy, Biophotonics Laboratory, Raina Boulevard 19, Riga LV-1586, Latvia
| | - Marta Lange
- University of Latvia, Institute of Atomic Physics and Spectroscopy, Biophotonics Laboratory, Raina Boulevard 19, Riga LV-1586, Latvia
| | - Ilze Lihacova
- University of Latvia, Institute of Atomic Physics and Spectroscopy, Biophotonics Laboratory, Raina Boulevard 19, Riga LV-1586, Latvia
| | - Janis Spigulis
- University of Latvia, Institute of Atomic Physics and Spectroscopy, Biophotonics Laboratory, Raina Boulevard 19, Riga LV-1586, Latvia
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16
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Szczesny SE, Edelstein RS, Elliott DM. DTAF dye concentrations commonly used to measure microscale deformations in biological tissues alter tissue mechanics. PLoS One 2014; 9:e99588. [PMID: 24915570 PMCID: PMC4051763 DOI: 10.1371/journal.pone.0099588] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 05/16/2014] [Indexed: 11/18/2022] Open
Abstract
Identification of the deformation mechanisms and specific components underlying the mechanical function of biological tissues requires mechanical testing at multiple levels within the tissue hierarchical structure. Dichlorotriazinylaminofluorescein (DTAF) is a fluorescent dye that is used to visualize microscale deformations of the extracellular matrix in soft collagenous tissues. However, the DTAF concentrations commonly employed in previous multiscale experiments (≥2000 µg/ml) may alter tissue mechanics. The objective of this study was to determine whether DTAF affects tendon fascicle mechanics and if a concentration threshold exists below which any observed effects are negligible. This information is valuable for guiding the continued use of this fluorescent dye in future experiments and for interpreting the results of previous work. Incremental strain testing demonstrated that high DTAF concentrations (≥100 µg/ml) increase the quasi-static modulus and yield strength of rat tail tendon fascicles while reducing their viscoelastic behavior. Subsequent multiscale testing and modeling suggests that these effects are due to a stiffening of the collagen fibrils and strengthening of the interfibrillar matrix. Despite these changes in tissue behavior, the fundamental deformation mechanisms underlying fascicle mechanics appear to remain intact, which suggests that conclusions from previous multiscale investigations of strain transfer are still valid. The effects of lower DTAF concentrations (≤10 µg/ml) on tendon mechanics were substantially smaller and potentially negligible; nevertheless, no concentration was found that did not at least slightly alter the tissue behavior. Therefore, future studies should either reduce DTAF concentrations as much as possible or use other dyes/techniques for measuring microscale deformations.
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Affiliation(s)
- Spencer E. Szczesny
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Rachel S. Edelstein
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware, United States of America
| | - Dawn M. Elliott
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware, United States of America
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