1
|
Kim B, Kelly TAN, Jung HJ, Beane OS, Bhumiratana S, Bouklas N, Cohen I, Bonassar LJ. Microscale strain concentrations in tissue-engineered osteochondral implants are dictated by local compositional thresholds and architecture. J Biomech 2024; 162:111882. [PMID: 38070296 DOI: 10.1016/j.jbiomech.2023.111882] [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: 05/25/2023] [Revised: 10/16/2023] [Accepted: 11/20/2023] [Indexed: 01/16/2024]
Abstract
Tissue-engineered osteochondral implants manufactured from condensed mesenchymal stem cell bodies have shown promise for treating focal cartilage defects. Notably, such manufacturing techniques have shown to successfully recapture the bulk mechanical properties of native cartilage. However, the relationships among the architectural features, local composition, and micromechanical environment within tissue-engineered cartilage from cell-based aggregates remain unclear. Understanding such relationships is crucial for identifying critical parameters that can predict in vivo performance. Therefore, this study investigated the relationship among architectural features, composition, and micromechanical behavior of tissue-engineered osteochondral implants. We utilized fast-confocal microscopy combined with a strain mapping technique to analyze the micromechanical behavior under quasi-static loading, as well as Fourier Transform Infrared Spectroscopy to analyze the local compositions. More specifically, we investigated the architectural features and compositional distributions generated from tissue maturation, along with macro- and micro-level strain distributions. Our results showed that under compression, cell-based aggregates underwent deformation followed by body movement, generating high local strain around the boundaries, where local aggrecan concentration was low and local collagen concentration was high. By analyzing the micromechanics and composition at the single aggregate length scale, we identified a strong threshold relationship between local strain and compositions. Namely at the aggrecan concentration below 0.015 arbitrary unit (A.U.) and the collagen concentration above 0.15 A.U., the constructs experienced greater than threefold increase in compressive strain. Overall, this study suggests that local compositional features are the primary driver of the local mechanical environment in tissue-engineered cartilage constructs, providing insight into potential quality control parameters for manufacturing tissue-engineered constructs.
Collapse
Affiliation(s)
- Byumsu Kim
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, United States
| | | | | | | | | | - Nikolaos Bouklas
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, United States
| | - Itai Cohen
- Department of Physics, Cornell University, Ithaca, NY, United States
| | - Lawrence J Bonassar
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, United States; Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States.
| |
Collapse
|
2
|
Ebrahimi M, Turkiewicz A, Finnilä MAJ, Saarakkala S, Englund M, Korhonen RK, Tanska P. Associations of human femoral condyle cartilage structure and composition with viscoelastic and constituent-specific material properties at different stages of osteoarthritis. J Biomech 2022; 145:111390. [PMID: 36442429 DOI: 10.1016/j.jbiomech.2022.111390] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 11/02/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022]
Abstract
The relationships between structure and function in human knee femoral cartilage are not well-known at different stages of osteoarthritis. Thus, our aim was to characterize the depth-dependent composition and structure (proteoglycan content, collagen network organization and collagen content) of normal and osteoarthritic human femoral condyle cartilage (n = 47) and relate them to their viscoelastic and constituent-specific mechanical properties that are obtained through dynamic sinusoidal testing and fibril-reinforced poroelastic material modeling of stress-relaxation testing, respectively. We characterized the proteoglycan content using digital densitometry, collagen network organization (orientation angle and anisotropy) using polarized light microscopy and collagen content using Fourier transform infrared spectroscopy. In the superficial cartilage (0-10 % of thickness), the collagen network disorganization and proteoglycan loss were associated with the smaller initial fibril network modulus - a parameter representing the pretension of the collagen network. Furthermore, the proteoglycan loss was associated with the greater strain-dependent fibril network modulus - a measure of nonlinear mechanical behavior. The proteoglycan loss was also associated with greater cartilage viscosity at a low loading frequency (0.005 Hz), while the collagen network disorganization was associated with greater cartilage viscosity at a high loading frequency (1 Hz). Our results suggest that proteoglycan loss and collagen network disorganization reduce the pretension of the collagen network while proteoglycan degradation also increases the nonlinear mechanical behavior of the collagen network. Further, the results also highlight that proteoglycan loss and collagen disorganization increase the viscosity of femoral cartilage, but their contribution to increased viscosity occurs in completely different loading frequencies.
Collapse
Affiliation(s)
- Mohammadhossein Ebrahimi
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland; Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland.
| | - Aleksandra Turkiewicz
- Faculty of Medicine, Department of Clinical Sciences Lund, Orthopaedics, Clinical Epidemiology Unit, Lund University, Lund, Sweden
| | - Mikko A J Finnilä
- Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Simo Saarakkala
- Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland; Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
| | - Martin Englund
- Faculty of Medicine, Department of Clinical Sciences Lund, Orthopaedics, Clinical Epidemiology Unit, Lund University, Lund, Sweden
| | - Rami K Korhonen
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland
| | - Petri Tanska
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland.
| |
Collapse
|
3
|
Warren MR, Vedadghavami A, Bhagavatula S, Bajpayee AG. Effects of polycationic drug carriers on the electromechanical and swelling properties of cartilage. Biophys J 2022; 121:3542-3561. [PMID: 35765244 PMCID: PMC9515003 DOI: 10.1016/j.bpj.2022.06.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 06/07/2022] [Accepted: 06/23/2022] [Indexed: 11/15/2022] Open
Abstract
Cationic nanocarriers offer a promising solution to challenges in delivering drugs to negatively charged connective tissues, such as to articular cartilage for the treatment of osteoarthritis (OA). However, little is known about the effects that cationic macromolecules may have on the mechanical properties of cartilage at high interstitial concentrations. We utilized arginine-rich cationic peptide carriers (CPCs) with varying net charge (from +8 to +20) to investigate the biophysical mechanisms of nanocarrier-induced alterations to cartilage biomechanical properties. We observed that CPCs increased the compressive modulus of healthy bovine cartilage explants by up to 70% and decreased the stiffness of glycosaminoglycan-depleted tissues (modeling OA) by 69%; in both cases, the magnitude of the change in stiffness correlated with the uptake of CPC charge variants. Next, we directly measured CPC-induced osmotic deswelling in cartilage tissue due to shielding of charge repulsions between anionic extracellular matrix constituents, with magnitudes of reductions between 36 and 64 kPa. We then demonstrated that electrostatic interactions were required for CPC-induced stiffening to occur, evidenced by no observed increase in tissue stiffness when measured in hypertonic bathing salinity. We applied a non-ideal Donnan osmotic model (under triphasic theory) to separate bulk modulus measurements into Donnan and non-Donnan components, which further demonstrated the conflicting charge-shielding and matrix-stiffening effects of CPCs. These results show that cationic drug carriers can alter tissue mechanical properties via multiple mechanisms, including the expected charge shielding as well as a novel stiffening phenomenon mediated by physical linkages. We introduce a model for how the magnitudes of these mechanical changes depend on tunable physical properties of the drug carrier, including net charge, size, and spatial charge distribution. We envision that the results and theory presented herein will inform the design of future cationic drug-delivery systems intended to treat diseases in a wide range of connective tissues.
Collapse
Affiliation(s)
- Matthew R Warren
- Department of Bioengineering, Northeastern University, Boston, Massachusetts
| | - Armin Vedadghavami
- Department of Bioengineering, Northeastern University, Boston, Massachusetts
| | - Sanjana Bhagavatula
- Department of Bioengineering, Northeastern University, Boston, Massachusetts
| | - Ambika G Bajpayee
- Department of Bioengineering, Northeastern University, Boston, Massachusetts; Department of Mechanical Engineering, Northeastern University, Boston, Massachusetts.
| |
Collapse
|
4
|
Wyse Jackson T, Michel J, Lwin P, Fortier LA, Das M, Bonassar LJ, Cohen I. Structural origins of cartilage shear mechanics. SCIENCE ADVANCES 2022; 8:eabk2805. [PMID: 35148179 PMCID: PMC8836800 DOI: 10.1126/sciadv.abk2805] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Articular cartilage is a remarkable material able to sustain millions of loading cycles over decades of use outperforming any synthetic substitute. Crucially, how extracellular matrix constituents alter mechanical performance, particularly in shear, remains poorly understood. Here, we present experiments and theory in support of a rigidity percolation framework that quantitatively describes the structural origins of cartilage's shear properties and how they arise from the mechanical interdependence of the collagen and aggrecan networks making up its extracellular matrix. This framework explains that near the cartilage surface, where the collagen network is sparse and close to the rigidity threshold, slight changes in either collagen or aggrecan concentrations, common in early stages of cartilage disease, create a marked weakening in modulus that can lead to tissue collapse. More broadly, this framework provides a map for understanding how changes in composition throughout the tissue alter its shear properties and ultimate in vivo function.
Collapse
Affiliation(s)
- Thomas Wyse Jackson
- Department of Physics, Cornell University, Ithaca, NY, USA
- Corresponding author. (T.W.J.); (I.C.)
| | - Jonathan Michel
- School of Mathematical Sciences, Rochester Institute of Technology, Rochester, NY, USA
| | - Pancy Lwin
- School of Mathematical Sciences, Rochester Institute of Technology, Rochester, NY, USA
| | - Lisa A. Fortier
- Department of Clinical Sciences, Cornell University, Ithaca, NY, USA
| | - Moumita Das
- School of Mathematical Sciences, Rochester Institute of Technology, Rochester, NY, USA
| | - Lawrence J. Bonassar
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA
| | - Itai Cohen
- Department of Physics, Cornell University, Ithaca, NY, USA
- Corresponding author. (T.W.J.); (I.C.)
| |
Collapse
|
5
|
Gologorsky CJ, Middendorf JM, Cohen I, Bonassar LJ. Depth-dependent patterns in shear modulus of temporomandibular joint cartilage correspond to tissue structure and anatomic location. J Biomech 2021; 129:110815. [PMID: 34706301 DOI: 10.1016/j.jbiomech.2021.110815] [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: 04/20/2021] [Revised: 10/07/2021] [Accepted: 10/08/2021] [Indexed: 11/17/2022]
Abstract
To fully understand TMJ cartilage degeneration and appropriate repair mechanisms, it is critical to understand the native structure-mechanics relationships of TMJ cartilage and any local variation that may occur in the tissue. Here, we used confocal elastography and digital image correlation to measure the depth-dependent shear properties as well as the structural properties of TMJ cartilage at different anatomic locations on the condyle to identify depth-dependent changes in shear mechanics and structure. We found that samples at every anatomic location showed qualitatively similar shear modulus profiles as a function of depth. In every sample, four distinct zones of mechanical behavior were observed, with shear modulus values spanning 3-5 orders of magnitude across zones. However, quantitative characteristics of shear modulus profiles varied by anatomic location, particularly zone size and location, with the most significant variation in zonal width occurring in the fibrocartilage surface layer (zone 1). This anatomic variation suggests that different locations on the TMJ condyle may play unique mechanical roles in TMJ function. Furthermore, zones identified in the mechanical data corresponded on a sample-by-sample basis to zones identified in the structural data, indicating the known structural zones of TMJ cartilage may also play unique mechanical roles in TMJ function.
Collapse
Affiliation(s)
| | - Jill M Middendorf
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA
| | - Itai Cohen
- Department of Physics, Cornell University, Clark Hall C7, Ithaca, NY 14853, USA
| | - Lawrence J Bonassar
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA; Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA.
| |
Collapse
|
6
|
Gao T, Boys AJ, Zhao C, Chan K, Estroff LA, Bonassar LJ. Non-Destructive Spatial Mapping of Glycosaminoglycan Loss in Native and Degraded Articular Cartilage Using Confocal Raman Microspectroscopy. Front Bioeng Biotechnol 2021; 9:744197. [PMID: 34778225 PMCID: PMC8581176 DOI: 10.3389/fbioe.2021.744197] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 09/24/2021] [Indexed: 12/02/2022] Open
Abstract
Articular cartilage is a collagen-rich tissue that provides a smooth, lubricated surface for joints and is also responsible for load bearing during movements. The major components of cartilage are water, collagen, and proteoglycans. Osteoarthritis is a degenerative disease of articular cartilage, in which an early-stage indicator is the loss of proteoglycans from the collagen matrix. In this study, confocal Raman microspectroscopy was applied to study the degradation of articular cartilage, specifically focused on spatially mapping the loss of glycosaminoglycans (GAGs). Trypsin digestion was used as a model for cartilage degradation. Two different scanning geometries for confocal Raman mapping, cross-sectional and depth scans, were applied. The chondroitin sulfate coefficient maps derived from Raman spectra provide spatial distributions similar to histological staining for glycosaminoglycans. The depth scans, during which subsurface data were collected without sectioning the samples, can also generate spectra and GAG distributions consistent with Raman scans of the surface-to-bone cross sections. In native tissue, both scanning geometries demonstrated higher GAG content at the deeper zone beneath the articular surface and negligible GAG content after trypsin degradation. On partially digested samples, both scanning geometries detected an ∼100 μm layer of GAG depletion. Overall, this research provides a technique with high spatial resolution (25 μm pixel size) to measure cartilage degradation without tissue sections using confocal Raman microspectroscopy, laying a foundation for potential in vivo measurements and osteoarthritis diagnosis.
Collapse
Affiliation(s)
- Tianyu Gao
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, United States
| | - Alexander J Boys
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, United States
| | - Crystal Zhao
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, United States
| | - Kiara Chan
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, United States
| | - Lara A Estroff
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, United States.,Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, United States
| | - Lawrence J Bonassar
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, United States.,Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States
| |
Collapse
|
7
|
Querido W, Kandel S, Pleshko N. Applications of Vibrational Spectroscopy for Analysis of Connective Tissues. Molecules 2021; 26:922. [PMID: 33572384 PMCID: PMC7916244 DOI: 10.3390/molecules26040922] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/30/2021] [Accepted: 02/04/2021] [Indexed: 02/07/2023] Open
Abstract
Advances in vibrational spectroscopy have propelled new insights into the molecular composition and structure of biological tissues. In this review, we discuss common modalities and techniques of vibrational spectroscopy, and present key examples to illustrate how they have been applied to enrich the assessment of connective tissues. In particular, we focus on applications of Fourier transform infrared (FTIR), near infrared (NIR) and Raman spectroscopy to assess cartilage and bone properties. We present strengths and limitations of each approach and discuss how the combination of spectrometers with microscopes (hyperspectral imaging) and fiber optic probes have greatly advanced their biomedical applications. We show how these modalities may be used to evaluate virtually any type of sample (ex vivo, in situ or in vivo) and how "spectral fingerprints" can be interpreted to quantify outcomes related to tissue composition and quality. We highlight the unparalleled advantage of vibrational spectroscopy as a label-free and often nondestructive approach to assess properties of the extracellular matrix (ECM) associated with normal, developing, aging, pathological and treated tissues. We believe this review will assist readers not only in better understanding applications of FTIR, NIR and Raman spectroscopy, but also in implementing these approaches for their own research projects.
Collapse
Affiliation(s)
| | | | - Nancy Pleshko
- Department of Bioengineering, Temple University, Philadelphia, PA 19122, USA; (W.Q.); (S.K.)
| |
Collapse
|
8
|
Irwin RM, Gao T, Boys AJ, Ortved K, Cohen I, Bonassar LJ. Microscale strain mapping demonstrates the importance of interface slope in the mechanics of cartilage repair. J Biomech 2020; 114:110159. [PMID: 33310276 DOI: 10.1016/j.jbiomech.2020.110159] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 11/10/2020] [Accepted: 11/25/2020] [Indexed: 01/20/2023]
Abstract
Achieving lateral integration of articular cartilage repair tissue with surrounding native cartilage remains a clinical challenge. Histological and bulk mechanical studies have identified extracellular matrix components that correlate with superior failure strength, but it is unclear how local changes in geometry and composition at the repair interface affect tissue strains under physiologic loading. Here, we investigated the effects of local compositional and interface geometry on lateral cartilage repair integration by coupling microscale Raman spectroscopy and confocal elastography to measure tissue strains under compressive and shear loading. Histological integration assessments did not have significant relationships with interface strains under compressive loading (p > 0.083) and only the perimeter attachment score was trending towards statistical significance with the |Exy| strain tensor under shear loading (p = 0.050). Interface slope had a stronger correlation with local tissue strains under compressive and shear loading compared to compositional measures of GAG, collagen, or proteins (compressive loading |Eyy| tensor: R2 = 0.400 (interface slope), 0.005 (GAG), 0.024 (collagen), and 0.012 (protein); shear loading |Exy| tensor: R2 = 0.457 (interface slope), 0.003 (GAG), 0.006 (collagen), and 0.000 (total protein)). These data support surgical publications detailing the need for vertical walls when debriding chondral defects. Current histological integration assessments and local compositional measures were insufficient for identifying the variation in interface strains under compressive and shear loading. Thus, our data points to the importance of controlling interface geometry at the time of surgery, which has implications for cartilage repair integration and long-term healing.
Collapse
Affiliation(s)
- Rebecca M Irwin
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States
| | - Tianyu Gao
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, United States
| | - Alexander J Boys
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, United States
| | - Kyla Ortved
- Comparative Orthopaedics Laboratory, Cornell University, Ithaca, NY, United States(1)
| | - Itai Cohen
- Department of Physics, Cornell University, Ithaca, NY, United States
| | - Lawrence J Bonassar
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States; Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, United States.
| |
Collapse
|
9
|
Sloan SR, Wipplinger C, Kirnaz S, Delgado R, Huang S, Shvets G, Härtl R, Bonassar LJ. Imaging the local biochemical content of native and injured intervertebral disc using Fourier transform infrared microscopy. JOR Spine 2020; 3:e1121. [PMID: 33392456 PMCID: PMC7770196 DOI: 10.1002/jsp2.1121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 07/20/2020] [Accepted: 08/03/2020] [Indexed: 12/12/2022] Open
Abstract
Alterations to the biochemical composition of the intervertebral disc (IVD) are hallmarks of aging and degeneration. Methods to assess biochemical content, such as histology, immunohistochemistry, and spectrophotometric assays, are limited in their ability to quantitatively analyze the spatial distribution of biochemical components. Fourier transform infrared (FTIR) microscopy is a biochemical analysis method that can yield both quantitative and high-resolution data about the spatial distribution of biochemical components. This technique has been largely unexplored for use with the IVD, and existing methods use complex analytical techniques that make results difficult to interpret. The objective of the present study is to describe an FTIR microscopy method that has been optimized for imaging the collagen and proteoglycan content of the IVD. The method was performed on intact and discectomized IVDs from the sheep lumbar spine after 6 weeks in vivo in order to validate FTIR microscopy in healthy and degenerated IVDs. FTIR microscopy quantified collagen and proteoglycan content across the entire IVD and showed local changes in biochemical content after discectomy that were not observed with traditional histological methods. Changes in collagen and proteoglycans content were found to have strong correlations with Pfirrmann grades of degeneration. This study demonstrates how FTIR microscopy is a valuable research tool that can be used to quantitatively assess the local biochemical composition of IVDs in development, degeneration, and repair.
Collapse
Affiliation(s)
- Stephen R. Sloan
- Meinig School of Biomedical EngineeringCornell UniversityIthacaNew YorkUSA
| | - Christoph Wipplinger
- Department of Neurological SurgeryWeill Cornell Medical CollegeNew YorkNew YorkUSA
| | - Sertaç Kirnaz
- Department of Neurological SurgeryWeill Cornell Medical CollegeNew YorkNew YorkUSA
| | - Robert Delgado
- Applied Engineering and PhysicsCornell UniversityIthacaNew YorkUSA
| | - Steven Huang
- Applied Engineering and PhysicsCornell UniversityIthacaNew YorkUSA
| | - Gennady Shvets
- Applied Engineering and PhysicsCornell UniversityIthacaNew YorkUSA
| | - Roger Härtl
- Department of Neurological SurgeryWeill Cornell Medical CollegeNew YorkNew YorkUSA
| | - Lawrence J. Bonassar
- Meinig School of Biomedical EngineeringCornell UniversityIthacaNew YorkUSA
- Sibley School of Mechanical and Aerospace EngineeringCornell UniversityIthacaNew YorkUSA
| |
Collapse
|
10
|
Lubbers R, van Schaarenburg RA, Kwekkeboom JC, Levarht EWN, Bakker AM, Mahdad R, Monteagudo S, Cherifi C, Lories RJ, Toes REM, Ioan-Facsinay A, Trouw LA. Complement component C1q is produced by isolated articular chondrocytes. Osteoarthritis Cartilage 2020; 28:675-684. [PMID: 31634584 DOI: 10.1016/j.joca.2019.09.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 09/10/2019] [Accepted: 09/21/2019] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Inflammation and innate immune responses may contribute to development and progression of Osteoarthritis (OA). Chondrocytes are the sole cell type of the articular cartilage and produce extracellular-matrix molecules. How inflammatory mediators reach chondrocytes is incompletely understood. Previous studies have shown that chondrocytes express mRNA encoding complement proteins such as C1q, suggesting local protein production, which has not been demonstrated conclusively. The aim of this study is to explore C1q production at the protein level by chondrocytes. DESIGN We analysed protein expression of C1q in freshly isolated and cultured human articular chondrocytes using Western blot, ELISA and flow cytometry. We examined changes in mRNA expression of collagen, MMP-1 and various complement genes upon stimulation with pro-inflammatory cytokines or C1q. mRNA expression of C1 genes was determined in articular mouse chondrocytes. RESULTS Primary human articular chondrocytes express genes encoding C1q, C1QA, C1QB, C1QC, and secrete C1q to the extracellular medium. Stimulation of chondrocytes with pro-inflammatory cytokines upregulated C1QA, C1QB, C1QC mRNA expression, although this was not confirmed at the protein level. Extracellular C1q bound to the chondrocyte surface dose dependently. In a pilot study, binding of C1q to chondrocytes resulted in changes in the expression of collagens with a decrease in collagen type 2 and an increase in type 10. Mouse articular chondrocytes also expressed C1QA, C1QB, C1QC, C1R and C1S at the mRNA level. CONCLUSIONS C1q protein can be expressed and secreted by human articular chondrocytes and is able to bind to chondrocytes influencing the relative collagen expression.
Collapse
Affiliation(s)
- R Lubbers
- Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands.
| | - R A van Schaarenburg
- Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands; Charles River, Leiden, the Netherlands
| | - J C Kwekkeboom
- Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands
| | - E W N Levarht
- Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands
| | - A M Bakker
- Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands
| | - R Mahdad
- Department of Orthopedic Surgery, Alrijne Hospital, Leiderdorp, the Netherlands
| | - S Monteagudo
- Laboratory of Tissue Homeostasis and Disease, Skeletal Biology and Engineering Research Center, KU Leuven, Leuven, Belgium
| | - C Cherifi
- Laboratory of Tissue Homeostasis and Disease, Skeletal Biology and Engineering Research Center, KU Leuven, Leuven, Belgium
| | - R J Lories
- Laboratory of Tissue Homeostasis and Disease, Skeletal Biology and Engineering Research Center, KU Leuven, Leuven, Belgium; Division of Rheumatology, University Hospitals Leuven, Belgium
| | - R E M Toes
- Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands
| | - A Ioan-Facsinay
- Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands
| | - L A Trouw
- Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands; Department of Immunohematology and Blood Transfusion, Leiden University Medical, Center, Leiden, the Netherlands.
| |
Collapse
|
11
|
Middendorf JM, Dugopolski C, Kennedy S, Blahut E, Cohen I, Bonassar LJ. Heterogeneous matrix deposition in human tissue engineered cartilage changes the local shear modulus and resistance to local construct buckling. J Biomech 2020; 105:109760. [PMID: 32276782 DOI: 10.1016/j.jbiomech.2020.109760] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 02/05/2020] [Accepted: 03/20/2020] [Indexed: 12/11/2022]
Abstract
Human tissue engineered cartilage is a promising solution for focal cartilage defects, but these constructs do not have the same local mechanical properties as native tissue. Most clinically relevant engineered cartilage constructs seed human chondrocytes onto a collagen scaffold, which buckles at low loads and strains. This buckling creates local regions of high strain that could cause cell death and damage the engineered tissue. Since human tissue engineered cartilage is commonly grown in-vivo prior to implantation, new matrix deposition could improve the local implant mechanics and prevent local tissue buckling. However, the relationship between local biochemical composition and the local mechanics or local buckling probability has never been quantified. Therefore, this study correlated the local biochemical composition of human tissue engineered cartilage constructs using Fourier transform infrared spectroscopy (FTIR) with the local shear modulus and local buckling probability. The local shear modulus and local buckling probability were obtained using a confocal elastography technique. The local shear modulus increased with increases in local aggrecan content in the interior region (inside the scaffold). A minimum amount of aggrecan was required to prevent local construct buckling at physiologic strains. Since the original scaffold was primarily composed of collagen, increases in collagen content due to new matrix deposition was minimal and had little effect on the mechanical properties. Thus, we concluded that aggrecan deposition inside the scaffold pores is the most effective way to improve the mechanical function and prevent local tissue damage in human tissue engineered cartilage constructs.
Collapse
Affiliation(s)
- Jill M Middendorf
- Sibley School of Mechanical Engineering, Cornell University, Ithaca, NY, USA
| | | | | | | | - Itai Cohen
- Physics, Cornell University, Ithaca, NY, USA
| | - Lawrence J Bonassar
- Sibley School of Mechanical Engineering, Cornell University, Ithaca, NY, USA; Meinig School of Biomedical Engineering Cornell University, Ithaca, NY, USA.
| |
Collapse
|