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Alizadeh Sardroud H, Wanlin T, Chen X, Eames BF. Cartilage Tissue Engineering Approaches Need to Assess Fibrocartilage When Hydrogel Constructs Are Mechanically Loaded. Front Bioeng Biotechnol 2022; 9:787538. [PMID: 35096790 PMCID: PMC8790514 DOI: 10.3389/fbioe.2021.787538] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/10/2021] [Indexed: 12/19/2022] Open
Abstract
Chondrocytes that are impregnated within hydrogel constructs sense applied mechanical force and can respond by expressing collagens, which are deposited into the extracellular matrix (ECM). The intention of most cartilage tissue engineering is to form hyaline cartilage, but if mechanical stimulation pushes the ratio of collagen type I (Col1) to collagen type II (Col2) in the ECM too high, then fibrocartilage can form instead. With a focus on Col1 and Col2 expression, the first part of this article reviews the latest studies on hyaline cartilage regeneration within hydrogel constructs that are subjected to compression forces (one of the major types of the forces within joints) in vitro. Since the mechanical loading conditions involving compression and other forces in joints are difficult to reproduce in vitro, implantation of hydrogel constructs in vivo is also reviewed, again with a focus on Col1 and Col2 production within the newly formed cartilage. Furthermore, mechanotransduction pathways that may be related to the expression of Col1 and Col2 within chondrocytes are reviewed and examined. Also, two recently-emerged, novel approaches of load-shielding and synchrotron radiation (SR)–based imaging techniques are discussed and highlighted for future applications to the regeneration of hyaline cartilage. Going forward, all cartilage tissue engineering experiments should assess thoroughly whether fibrocartilage or hyaline cartilage is formed.
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Affiliation(s)
- Hamed Alizadeh Sardroud
- Division of Biomedical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, SK, Canada
- *Correspondence: Hamed Alizadeh Sardroud,
| | - Tasker Wanlin
- Department of Anatomy, Physiology, and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Xiongbiao Chen
- Division of Biomedical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Mechanical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, SK, Canada
| | - B. Frank Eames
- Division of Biomedical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Anatomy, Physiology, and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
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Atelocollagen-Embedded Chondrocyte Precursors as a Treatment for Grade-4 Cartilage Defects of the Femoral Condyle: A Case Series with up to 9-Year Follow-Up. Biomolecules 2021; 11:biom11070942. [PMID: 34202002 PMCID: PMC8301975 DOI: 10.3390/biom11070942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/17/2021] [Accepted: 06/22/2021] [Indexed: 12/22/2022] Open
Abstract
We demonstrated the safety and efficacy of autologous chondrocyte precursor (CP) cell therapy in repairing Grade 4 cartilage defects of medial femoral condyles. The autologous bone marrow mesenchymal stem cells of each participant were isolated, amplified, and then differentiated into CPs in atelocollagen. Neotissues made of CPs were implanted into cartilage defects with an average cell density of 4.9 ± 2.1 × 106 cells/cm2 through arthrotomy. The knee function was evaluated with the International Knee Documentation Committee (IKDC) subjective knee form. Patients' knee functions significantly improved by the 28th week (IKDC score = 68.3 ± 12.1), relative to the initial functionality before the CP therapy (IKDC score = 46.1 ± 16.4, p-value = 0.0014). Nine of these twelve patients maintained good knee functions for 9 years post-implantation (IKDC score = 69.8 ± 12.3) at levels higher than the pre-implantation values (p-value = 0.0018). Patients were evaluated with MRI and arthroscopy, and the defective sites exhibited a smooth surface without a gap between the implant and host tissue. This study demonstrates that autologous CPs successfully engraft into the host tissue and result in the re-formation of hyaline-like cartilage, thereby improving the impaired knee functions. Most importantly, no adverse event was reported during this long-term follow-up period.
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Bartolotti I, Roseti L, Petretta M, Grigolo B, Desando G. A Roadmap of In Vitro Models in Osteoarthritis: A Focus on Their Biological Relevance in Regenerative Medicine. J Clin Med 2021; 10:1920. [PMID: 33925222 PMCID: PMC8124812 DOI: 10.3390/jcm10091920] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/20/2021] [Accepted: 04/26/2021] [Indexed: 01/15/2023] Open
Abstract
Osteoarthritis (OA) is a multifaceted musculoskeletal disorder, with a high prevalence worldwide. Articular cartilage and synovial membrane are among the main biological targets in the OA microenvironment. Gaining more knowledge on the accuracy of preclinical in vitro OA models could open innovative avenues in regenerative medicine to bridge major gaps, especially in translation from animals to humans. Our methodological approach entailed searches on Scopus, the Web of Science Core Collection, and EMBASE databases to select the most relevant preclinical in vitro models for studying OA. Predicting the biological response of regenerative strategies requires developing relevant preclinical models able to mimic the OA milieu influencing tissue responses and organ complexity. In this light, standard 2D culture models lack critical properties beyond cell biology, while animal models suffer from several limitations due to species differences. In the literature, most of the in vitro models only recapitulate a tissue compartment, by providing fragmented results. Biotechnological advances may enable scientists to generate new in vitro models that combine easy manipulation and organ complexity. Here, we review the state-of-the-art of preclinical in vitro models in OA and outline how the different preclinical systems (inflammatory/biomechanical/microfluidic models) may be valid tools in regenerative medicine, describing their pros and cons. We then discuss the prospects of specific and combinatorial models to predict biological responses following regenerative approaches focusing on mesenchymal stromal cells (MSCs)-based therapies to reduce animal testing.
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Affiliation(s)
- Isabella Bartolotti
- Laboratorio RAMSES, IRCCS Istituto Ortopedico Rizzoli, via di Barbiano 1/10, 40136 Bologna, Italy; (I.B.); (M.P.); (B.G.)
| | - Livia Roseti
- Laboratorio RAMSES, IRCCS Istituto Ortopedico Rizzoli, via di Barbiano 1/10, 40136 Bologna, Italy; (I.B.); (M.P.); (B.G.)
| | - Mauro Petretta
- Laboratorio RAMSES, IRCCS Istituto Ortopedico Rizzoli, via di Barbiano 1/10, 40136 Bologna, Italy; (I.B.); (M.P.); (B.G.)
- RegenHu Company, Z.I Du Vivier 22, 1690 Villaz-St-Pierre, Switzerland
| | - Brunella Grigolo
- Laboratorio RAMSES, IRCCS Istituto Ortopedico Rizzoli, via di Barbiano 1/10, 40136 Bologna, Italy; (I.B.); (M.P.); (B.G.)
| | - Giovanna Desando
- Laboratorio RAMSES, IRCCS Istituto Ortopedico Rizzoli, via di Barbiano 1/10, 40136 Bologna, Italy; (I.B.); (M.P.); (B.G.)
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Schneider MC, Lalitha Sridhar S, Vernerey FJ, Bryant SJ. Spatiotemporal neocartilage growth in matrix-metalloproteinase-sensitive poly(ethylene glycol) hydrogels under dynamic compressive loading: an experimental and computational approach. J Mater Chem B 2020; 8:2775-2791. [PMID: 32155233 PMCID: PMC7695218 DOI: 10.1039/c9tb02963j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Enzyme-sensitive hydrogels containing encapsulated chondrocytes are a promising platform for cartilage tissue engineering. However, the growth of neotissue is closely coupled to the degradation of the hydrogel and is further complicated due to the encapsulated cells serving as the enzyme source for hydrogel degradation. To better understand these coupled processes, this study combined experimental and computational methods to analyze the transition from hydrogel to neotissue in a biomimetic MMP-sensitive poly(ethylene glycol) (PEG) hydrogel with encapsulated chondrocytes. A physics-based computational model that describes spatial heterogeneities in cell distribution was used. Experimentally, cell-laden hydrogels were cultured for six weeks under free swelling or subjected daily to one-hour of dynamic compressive loading. Extracellular matrix (ECM) synthesis rates were used as model inputs, and the model was fit to the experimentally determined construct modulus over time for the free swelling condition. Experimentally, ECM accumulation comprising collagen II and aggrecan increased over time concomitant with hydrogel degradation observed by a loss in PEG. Simulations demonstrated rapid degradation in regions of high cell density (i.e., cell clusters) reaching complete degradation by day 13, which facilitated localized ECM growth. Regions of low cell density degraded more slowly, had limited ECM, and led to the decrease in construct modulus during the first two weeks. The primary difference between the two culture environments was greater ECM accumulation in the clusters under free swelling, which facilitated a faster recovery in construct modulus. By 6 weeks the compressive modulus increased 2.5-fold to 107 kPa under free swelling, but dropped 1.6-fold to 26 kPa under loading. In summary, this biomimetic MMP-sensitive hydrogel supports neocartilage growth by facilitating rapid ECM growth within cell clusters, which was followed by slower growth in the rest of the hydrogel. Subtle temporal differences in hydrogel degradation and ECM accumulation, however, had a significant impact on the evolving mechanical properties.
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Affiliation(s)
- Margaret C Schneider
- Department of Chemical and Biological Engineering, University of Colorado, 3415 Colorado Ave., Boulder, Colorado 80309-0596, USA.
| | - Shankar Lalitha Sridhar
- Department of Mechanical Engineering, University of Colorado, 1111 Engineering Dr., Boulder, Colorado 80309-0596, USA.
| | - Franck J Vernerey
- Department of Mechanical Engineering, University of Colorado, 1111 Engineering Dr., Boulder, Colorado 80309-0596, USA. and Materials Science and Engineering Program, University of Colorado, 3415 Colorado Ave., Boulder, Colorado 80309-0596, USA
| | - Stephanie J Bryant
- Department of Chemical and Biological Engineering, University of Colorado, 3415 Colorado Ave., Boulder, Colorado 80309-0596, USA. and Materials Science and Engineering Program, University of Colorado, 3415 Colorado Ave., Boulder, Colorado 80309-0596, USA and Biofrontiers Institute, University of Colorado, 3415 Colorado Ave., Boulder, Colorado 80309-0596, USA
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Primary human chondrocytes respond to compression with phosphoproteomic signatures that include microtubule activation. J Biomech 2019; 97:109367. [PMID: 31607375 DOI: 10.1016/j.jbiomech.2019.109367] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 09/14/2019] [Accepted: 09/22/2019] [Indexed: 12/20/2022]
Abstract
Chondrocytes are responsible for maintaining the cartilage that helps joints bear load and move smoothly. These cells typically respond to physiological compression with pathways consistent with matrix synthesis, and chondrocyte mechanotransduction is essential for homeostasis. In osteoarthritis (OA), chondrocyte mechanotransduction appears to be dysregulated, yet the mechanisms remain poorly understood. The objective of this study is to document the phosphoproteomic responses of primary osteoarthritic chondrocytes to physiological sinusoidal compression. We show that OA chondrocytes respond to physiological compression by first activating proteins consistent with cytoskeletal remodeling and decreased transcription, and then later activating proteins for transcription. These results show that several microtubule-related proteins respond to compression. Our results demonstrate that compression is a relevant physiological stimulus for osteoarthritic chondrocytes. Future analyses may build on these results to find differences in compression-induced phosphoproteins between normal and OA cells that lead to druggable targets to restore homeostasis to diseased joints.
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Vaca-González JJ, Guevara JM, Moncayo MA, Castro-Abril H, Hata Y, Garzón-Alvarado DA. Biophysical Stimuli: A Review of Electrical and Mechanical Stimulation in Hyaline Cartilage. Cartilage 2019; 10:157-172. [PMID: 28933195 PMCID: PMC6425540 DOI: 10.1177/1947603517730637] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE Hyaline cartilage degenerative pathologies induce morphologic and biomechanical changes resulting in cartilage tissue damage. In pursuit of therapeutic options, electrical and mechanical stimulation have been proposed for improving tissue engineering approaches for cartilage repair. The purpose of this review was to highlight the effect of electrical stimulation and mechanical stimuli in chondrocyte behavior. DESIGN Different information sources and the MEDLINE database were systematically revised to summarize the different contributions for the past 40 years. RESULTS It has been shown that electric stimulation may increase cell proliferation and stimulate the synthesis of molecules associated with the extracellular matrix of the articular cartilage, such as collagen type II, aggrecan and glycosaminoglycans, while mechanical loads trigger anabolic and catabolic responses in chondrocytes. CONCLUSION The biophysical stimuli can increase cell proliferation and stimulate molecules associated with hyaline cartilage extracellular matrix maintenance.
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Affiliation(s)
- Juan J. Vaca-González
- Biomimetics Laboratory, Instituto de Biotecnología, Universidad Nacional de Colombia, Bogota, Colombia
- Numerical Methods and Modeling Research Group (GNUM), Universidad Nacional de Colombia, Bogota, Colombia
| | - Johana M. Guevara
- Institute for the Study of Inborn Errors of Metabolism, Pontificia Universidad Javeriana, Bogota, Colombia
| | - Miguel A. Moncayo
- Biomimetics Laboratory, Instituto de Biotecnología, Universidad Nacional de Colombia, Bogota, Colombia
- Numerical Methods and Modeling Research Group (GNUM), Universidad Nacional de Colombia, Bogota, Colombia
| | - Hector Castro-Abril
- Biomimetics Laboratory, Instituto de Biotecnología, Universidad Nacional de Colombia, Bogota, Colombia
- Numerical Methods and Modeling Research Group (GNUM), Universidad Nacional de Colombia, Bogota, Colombia
| | - Yoshie Hata
- Biomimetics Laboratory, Instituto de Biotecnología, Universidad Nacional de Colombia, Bogota, Colombia
| | - Diego A. Garzón-Alvarado
- Biomimetics Laboratory, Instituto de Biotecnología, Universidad Nacional de Colombia, Bogota, Colombia
- Numerical Methods and Modeling Research Group (GNUM), Universidad Nacional de Colombia, Bogota, Colombia
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Stochastic Resonance with Dynamic Compression Improves the Growth of Adult Chondrocytes in Agarose Gel Constructs. Ann Biomed Eng 2018; 47:243-256. [PMID: 30187237 DOI: 10.1007/s10439-018-02123-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 08/25/2018] [Indexed: 02/06/2023]
Abstract
Dynamic mechanical stimulation has been an effective method to improve the growth of tissue engineering cartilage constructs derived from immature cells. However, when more mature cell populations are used, results are often variable due to the differing responses of these cells to external stimuli. This can be especially detrimental in the case of mechanical loading. In previous studies, multi-modal mechanical stimulation in the form of stochastic resonance was shown to be effective at improving the growth of young bovine chondrocytes. Thus, the aim of this study was to investigate the short-term and long-term effects of stochastic resonance on two groups of bovine chondrocytes, adult (> 30 month) and juvenile (~ 18 months). While the juvenile cells outperformed the adult cells in terms of their anabolic response to loading, combined mechanical loading for both age groups resulted in greater matrix synthesis compared to compressive loading alone. In the adult cells, potential pathological tissue formation was evident with the presence of cell clustering. However, the presence of broad-band mechanical vibrations (alone or with compressive loading) appeared to mitigate this response and allow these cells to attain a growth response similar to the juvenile, unstimulated cells. Therefore, the use of stochastic resonance appears to show promise as a method to improve the formation and properties of tissue engineered cartilage constructs, irrespective of cell age.
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Anderson DE, Johnstone B. Dynamic Mechanical Compression of Chondrocytes for Tissue Engineering: A Critical Review. Front Bioeng Biotechnol 2017; 5:76. [PMID: 29322043 PMCID: PMC5732133 DOI: 10.3389/fbioe.2017.00076] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 11/23/2017] [Indexed: 01/19/2023] Open
Abstract
Articular cartilage functions to transmit and translate loads. In a classical structure-function relationship, the tissue resides in a dynamic mechanical environment that drives the formation of a highly organized tissue architecture suited to its biomechanical role. The dynamic mechanical environment includes multiaxial compressive and shear strains as well as hydrostatic and osmotic pressures. As the mechanical environment is known to modulate cell fate and influence tissue development toward a defined architecture in situ, dynamic mechanical loading has been hypothesized to induce the structure-function relationship during attempts at in vitro regeneration of articular cartilage. Researchers have designed increasingly sophisticated bioreactors with dynamic mechanical regimes, but the response of chondrocytes to dynamic compression and shear loading remains poorly characterized due to wide variation in study design, system variables, and outcome measurements. We assessed the literature pertaining to the use of dynamic compressive bioreactors for in vitro generation of cartilaginous tissue from primary and expanded chondrocytes. We used specific search terms to identify relevant publications from the PubMed database and manually sorted the data. It was very challenging to find consensus between studies because of species, age, cell source, and culture differences, coupled with the many loading regimes and the types of analyses used. Early studies that evaluated the response of primary bovine chondrocytes within hydrogels, and that employed dynamic single-axis compression with physiologic loading parameters, reported consistently favorable responses at the tissue level, with upregulation of biochemical synthesis and biomechanical properties. However, they rarely assessed the cellular response with gene expression or mechanotransduction pathway analyses. Later studies that employed increasingly sophisticated biomaterial-based systems, cells derived from different species, and complex loading regimes, did not necessarily corroborate prior positive results. These studies report positive results with respect to very specific conditions for cellular responses to dynamic load but fail to consistently achieve significant positive changes in relevant tissue engineering parameters, particularly collagen content and stiffness. There is a need for standardized methods and analyses of dynamic mechanical loading systems to guide the field of tissue engineering toward building cartilaginous implants that meet the goal of regenerating articular cartilage.
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Affiliation(s)
- Devon E Anderson
- Department of Orthopaedics and Rehabilitation, Oregon Health & Science University, Portland, OR, United States
| | - Brian Johnstone
- Department of Orthopaedics and Rehabilitation, Oregon Health & Science University, Portland, OR, United States
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Szychlinska MA, Stoddart MJ, D'Amora U, Ambrosio L, Alini M, Musumeci G. Mesenchymal Stem Cell-Based Cartilage Regeneration Approach and Cell Senescence: Can We Manipulate Cell Aging and Function? TISSUE ENGINEERING PART B-REVIEWS 2017; 23:529-539. [PMID: 28514935 DOI: 10.1089/ten.teb.2017.0083] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Aging is the most prominent risk factor triggering several degenerative diseases, such as osteoarthritis (OA). Due to its poor self-healing capacity, once injured cartilage needs to be reestablished. This process might be approached through resorting to cell-based therapies and/or tissue engineering. Human mesenchymal stem cells (MSCs) represent a promising approach due to their chondrogenic differentiation potential. Presently, in vitro chondrogenic differentiation of MSCs is limited by two main reasons as follows: aging of MSCs, which determines the loss of cell proliferative and differentiation capacity and MSC-derived chondrocyte hypertrophic differentiation, which limits the use of these cells in cartilage tissue regeneration approach. The effect of aging on MSCs is fundamental for stem cell-based therapy development, especially in older subjects. In the present review we focus on homeostasis alterations occurring in MSC-derived chondrocytes during in vitro aging. Moreover, we deal with potential cell aging regulation approaches, such as cell stimulation through telomerase activators, mechanical strain, and epigenetic regulation. Future investigations in this field might provide new insights into innovative strategies for cartilage regeneration and potentially inspire novel therapeutic approaches for OA treatment.
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Affiliation(s)
- Marta A Szychlinska
- 1 Human Anatomy and Histology Section, Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania , Catania, Italy
| | - Martin J Stoddart
- 2 Musculoskeletal Regeneration, AO Research Institute Davos , Davos Platz, Switzerland
| | - Ugo D'Amora
- 3 Institute of Polymers , Composites and Biomaterials, National Research Council of Italy, Naples, Italy
| | - Luigi Ambrosio
- 3 Institute of Polymers , Composites and Biomaterials, National Research Council of Italy, Naples, Italy .,4 Department of Chemical Science and Materials Technology, National Research Council of Italy , Rome, Italy
| | - Mauro Alini
- 2 Musculoskeletal Regeneration, AO Research Institute Davos , Davos Platz, Switzerland
| | - Giuseppe Musumeci
- 1 Human Anatomy and Histology Section, Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania , Catania, Italy .,5 Department of Health, Institut des Etudes Universitaries , UniPoliSI, Veyras, Switzerland
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10
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Chu S, Sridhar SL, Akalp U, Skaalure SC, Vernerey FJ, Bryant SJ. * Understanding the Spatiotemporal Degradation Behavior of Aggrecanase-Sensitive Poly(ethylene glycol) Hydrogels for Use in Cartilage Tissue Engineering. Tissue Eng Part A 2017; 23:795-810. [PMID: 28351221 DOI: 10.1089/ten.tea.2016.0490] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Enzyme-sensitive hydrogels are promising cell delivery vehicles for cartilage tissue engineering. However, a better understanding of their spatiotemporal degradation behavior and its impact on tissue growth is needed. The goal of this study was to combine experimental and computational approaches to provide new insights into spatiotemporal changes in hydrogel crosslink density and extracellular matrix (ECM) growth and how these changes influence the evolving macroscopic properties as a function of time. Hydrogels were designed from aggrecanase-sensitive peptide crosslinks using a simple and robust thiol-norbornene photoclick reaction. To study the influence of variations in cellular activity of different donors, chondrocytes were isolated from either juvenile or adult bovine donors. Initial studies were performed to validate and calibrate the model against experiments. Through this process, two key features were identified. These included spatial variations in the hydrogel crosslink density in the immediate vicinity of the cell and the presence of cell clustering within the construct. When these spatial heterogeneities were incorporated into the computational model along with model inputs of initial hydrogel properties and cellular activity (i.e., enzyme and ECM production rates), the model was able to capture the spatial and temporal evolution of ECM growth that was observed experimentally for both donors. In this study, the juvenile chondrocytes produced an interconnected matrix within the cell clusters leading to overall improved ECM growth, while the adult chondrocytes resulted in poor ECM growth. Overall, the computational model was able to capture the spatiotemporal ECM growth of two different donors and provided new insights into the importance of spatial heterogeneities in facilitating ECM growth. Our long-term goal is to use this model to predict optimal hydrogel designs for a wide range of donors and improve cartilage tissue engineering.
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Affiliation(s)
- Stanley Chu
- 1 Department of Chemical and Biological Engineering, University of Colorado , Boulder, Colorado
| | | | - Umut Akalp
- 2 Department of Mechanical Engineering, University of Colorado , Boulder, Colorado
| | - Stacey C Skaalure
- 1 Department of Chemical and Biological Engineering, University of Colorado , Boulder, Colorado
| | - Franck J Vernerey
- 2 Department of Mechanical Engineering, University of Colorado , Boulder, Colorado.,4 Material Science and Engineering Program, University of Colorado , Boulder, Colorado
| | - Stephanie J Bryant
- 1 Department of Chemical and Biological Engineering, University of Colorado , Boulder, Colorado.,3 BioFrontiers Institute, University of Colorado , Boulder, Colorado.,4 Material Science and Engineering Program, University of Colorado , Boulder, Colorado
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Schneider MC, Barnes CA, Bryant SJ. Characterization of the chondrocyte secretome in photoclickable poly(ethylene glycol) hydrogels. Biotechnol Bioeng 2017; 114:2096-2108. [PMID: 28436002 DOI: 10.1002/bit.26320] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 12/28/2016] [Accepted: 04/17/2017] [Indexed: 12/30/2022]
Abstract
Poly(ethylene glycol) (PEG) hydrogels are highly tunable platforms that are promising cell delivery vehicles for chondrocytes and cartilage tissue engineering. In addition to characterizing the type of extracellular matrix (ECM) that forms, understanding the types of proteins that are secreted by encapsulated cells may be important. Thus, the objectives for this study were to characterize the secretome of chondrocytes encapsulated in PEG hydrogels and determine whether the secretome varies as a function of hydrogel stiffness and culture condition. Bovine chondrocytes were encapsulated in photoclickable PEG hydrogels with a compressive modulus of 8 and 46 kPa and cultured under free swelling or dynamic compressive loading conditions. Cartilage ECM deposition was assessed by biochemical assays and immunohistochemistry. The conditioned medium was analyzed by liquid chromatography-tandem mass spectrometry. Chondrocytes maintained their phenotype within the hydrogels and deposited cartilage-specific ECM that increased over time and included aggrecan and collagens II and VI. Analysis of the secretome revealed a total of 64 proteins, which were largely similar among all experimental conditions. The identified proteins have diverse functions such as biological regulation, response to stress, and collagen fibril organization. Notably, many of the proteins important to the assembly of a collagen-rich cartilage ECM were identified and included collagen types II(α1), VI (α1, α2, and α3), IX (α1), XI (α1 and α2), and biglycan. In addition, many of the other identified proteins have been reported to be present within cell-secreted exosomes. In summary, chondrocytes encapsulated within photoclickable PEG hydrogels secrete many types of proteins that diffuse out of the hydrogel and which have diverse functions, but which are largely preserved across different hydrogel culture environments. Biotechnol. Bioeng. 2017;114: 2096-2108. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Margaret C Schneider
- Department of Chemical and Biological Engineering, University of Colorado, 3415 Colorado Ave, Campus Box 596, Boulder 80309, Colorado.,Biofrontiers Institute, University of Colorado, Boulder, Colorado
| | | | - Stephanie J Bryant
- Department of Chemical and Biological Engineering, University of Colorado, 3415 Colorado Ave, Campus Box 596, Boulder 80309, Colorado.,Biofrontiers Institute, University of Colorado, Boulder, Colorado.,Material Science and Engineering Program, University of Colorado, Boulder, Colorado
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12
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GUEVARA JOHANAMARIA, GOMEZ MARIALUCIAGUTIERREZ, BARRERA LA LUISALEJANDRO, GARZÓN-ALVARADO DIEGOALEXANDER. DEVELOPMENTAL SCENARIOS OF THE EPIPHYSIS AND GROWTH PLATE UPON MECHANICAL LOADING: A COMPUTATIONAL MODEL. J MECH MED BIOL 2016. [DOI: 10.1142/s0219519416500986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Long bone growth relies on the continuous bone formation from cartilaginous tissue (endochondral ossification). This process starts in the central region (diaphysis) of the forming bone and short before birth, ossification starts in bone extremes (epiphysis). A cartilaginous region known as the growth plate is maintained until adolescence between epiphysis and diaphysis to further contribute to longitudinal growth. Even though there are several biochemical factors controlling this process, there is evidence revealing an important regulatory role of mechanical stimuli. Up to now approaches to understand mechanical effects on ossification have been limited to epiphysis. In this work, based on Carter's mathematical model for epiphyseal ossification, we explored human growth plate response to mechanical loads. We analyzed growth plate stress distribution using finite element method for a generic bone considering different stages of bone development in order to shed light on mechanical contribution to growth plate function. Results obtained revealed that mechanical environment within the growth plate change as epiphyseal ossification progresses. Furthermore, results were compared with physiological behavior, as reported in literature, to analyze the role of mechanical stimulus over development. Our results suggest that mechanical stimuli may play different regulation roles on growth plate behavior through normal long bone development. However, as this approach only took into account mechanical aspects, failed to accurately predict biological behavior in some stages. In order to derive biologically relevant information from computational models it is necessary to consider biological contribution and possible mechanical–biochemical interactions affecting human growth plate physiology. Along these lines, we propose the dilatatorial parameter k used by Carter et al. should assume different values corresponding to the developmental stage in question. Thus, reflecting biochemical contribution changes over time.
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Affiliation(s)
- JOHANA MARIA GUEVARA
- Institute for the Study of Inborn Errors of Metabolism, Pontificia Universidad Javeriana, Bogotá, Colombia
| | | | - LUIS ALEJANDRO BARRERA LA
- Institute for the Study of Inborn Errors of Metabolism, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - DIEGO ALEXANDER GARZÓN-ALVARADO
- Numerical Methods and Modeling Research Group (GNUM), Universidad Nacional de Colombia, Biomimetics Laboratory, Institute of Biotechnology, Universidad Nacional de Colombia, Bogotá, Colombia
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13
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Neumann AJ, Quinn T, Bryant SJ. Nondestructive evaluation of a new hydrolytically degradable and photo-clickable PEG hydrogel for cartilage tissue engineering. Acta Biomater 2016; 39:1-11. [PMID: 27180026 DOI: 10.1016/j.actbio.2016.05.015] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 05/02/2016] [Accepted: 05/11/2016] [Indexed: 11/30/2022]
Abstract
UNLABELLED Photopolymerizable and hydrolytically labile poly(ethylene glycol) (PEG) hydrogels formed from photo-clickable reactions were investigated as cell delivery platforms for cartilage tissue engineering (TE). PEG hydrogels were formed from thiol-norbornene PEG macromers whereby the crosslinks contained caprolactone segments with hydrolytically labile ester linkages. Juvenile bovine chondrocytes encapsulated in the hydrogels were cultured for up to four weeks and assessed biochemically and histologically, using standard destructive assays, and for mechanical and ultrasound properties, as nondestructive assays. Bulk degradation of acellular hydrogels was confirmed by a decrease in compressive modulus and an increase in mass swelling ratio over time. Chondrocytes deposited increasing amounts of sulfated glycosaminoglycans and collagens in the hydrogels with time. Spatially, collagen type II and aggrecan were present in the neotissue with formation of a territorial matrix beginning at day 21. Nondestructive measurements revealed an 8-fold increase in compressive modulus from days 7 to 28, which correlated with total collagen content. Ultrasound measurements revealed changes in the constructs over time, which differed from the mechanical properties, and appeared to correlate with ECM structure and organization shown by immunohistochemical analysis. Overall, non-destructive and destructive measurements show that this new hydrolytically degradable PEG hydrogel is promising for cartilage TE. STATEMENT OF SIGNIFICANCE Designing synthetic hydrogels whose degradation matches tissue growth is critical to maintaining mechanical integrity as the hydrogel degrades and new tissue forms, but is challenging due to the nature of the hydrogel crosslinks that inhibit diffusion of tissue matrix molecules. This study details a promising, new, photo-clickable and synthetic hydrogel whose degradation supports cartilaginous tissue matrix growth leading to the formation of a territorial matrix, concomitant with an increase in mechanical properties. Nondestructive assays based on mechanical and ultrasonic properties were also investigated using a novel instrument and found to correlate with matrix deposition and evolution. In sum, this study presents a new hydrogel platform combined with nondestructive assessments, which together have potential for in vitro cartilage tissue engineering.
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Affiliation(s)
- Alexander J Neumann
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, USA
| | - Timothy Quinn
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - Stephanie J Bryant
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, USA; BioFrontiers Institute, University of Colorado, Boulder, CO 80309, USA; Materials Science and Engineering Program, University of Colorado, Boulder, CO 80309, USA.
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Weber JF, Waldman SD. Stochastic resonance is a method to improve the biosynthetic response of chondrocytes to mechanical stimulation. J Orthop Res 2016; 34:231-9. [PMID: 26234431 DOI: 10.1002/jor.23000] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 07/23/2015] [Indexed: 02/04/2023]
Abstract
Cellular mechanosensitivity is an important factor during the mechanical stimulation of tissue engineered cartilage. While the application of mechanical stimuli improves tissue growth and properties, chondrocytes also rapidly desensitize under prolonged loading thereby limiting its effectiveness. One potential method to mitigate load-induced desensitization is by superimposing noise on the loading waveforms ("stochastic resonance"). Thus, the purpose of this study was to investigate the effects of stochastic resonance on chondrocyte matrix metabolism. Chondrocyte-seeded agarose gels were subjected to dynamic compressive loading, with or without, superimposed vibrations of different amplitudes and frequency bandwidths. Changes in matrix biosynthesis were determined by radioisotope incorporation and subsequent effects on intracellular calcium signaling were evaluated by confocal microscopy. Although dependent on the duration of loading, superimposed vibrations improved cellular sensitivity to mechanical loading by further increasing matrix synthesis between 20-60%. Stochastic resonance also appeared to limit load-induced desensitization by maintaining sensitivity under desensitized loading conditions. While superimposed vibrations had little effect on the magnitude of intracellular calcium signaling, recovery of mechanosensitivity after stimulation was achieved at a faster rate suggesting that less time may be required between successive loading applications. Thus, stochastic resonance appears to be a valuable tool during the mechanical stimulation of cartilage constructs, even when suboptimal stimulation conditions are used.
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Affiliation(s)
- Joanna F Weber
- Department of Mechanical and Materials Engineering, Queen's University, Kingston, Ontario, Canada.,Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Stephen D Waldman
- Department of Mechanical and Materials Engineering, Queen's University, Kingston, Ontario, Canada.,Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.,Department of Chemical Engineering, Ryerson University, Toronto, Ontario, Canada
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Zignego DL, Hilmer JK, June RK. Mechanotransduction in primary human osteoarthritic chondrocytes is mediated by metabolism of energy, lipids, and amino acids. J Biomech 2015; 48:4253-61. [PMID: 26573901 DOI: 10.1016/j.jbiomech.2015.10.038] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 10/23/2015] [Accepted: 10/23/2015] [Indexed: 12/11/2022]
Abstract
Chondrocytes are the sole cell type found in articular cartilage and are repeatedly subjected to mechanical loading in vivo. We hypothesized that physiological dynamic compression results in changes in energy metabolism to produce proteins for maintenance of the pericellular and extracellular matrices. The objective of this study was to develop an in-depth understanding for the short term (<30min) chondrocyte response to sub-injurious, physiological compression by analyzing metabolomic profiles for human chondrocytes harvested from femoral heads of osteoarthritic donors. Cell-seeded agarose constructs were randomly assigned to experimental groups, and dynamic compression was applied for 0, 15, or 30min. Following dynamic compression, metabolites were extracted and detected by HPLC-MS. Untargeted analyzes examined changes in global metabolomics profiles and targeted analysis examined the expression of specific metabolites related to central energy metabolism. We identified hundreds of metabolites that were regulated by applied compression, and we report the detection of 16 molecules not found in existing metabolite databases. We observed patient-specific mechanotransduction with aging dependence. Targeted studies found a transient increase in the ratio of NADP+ to NADPH and an initial decrease in the ratio of GDP to GTP, suggesting a flux of energy into the TCA cycle. By characterizing metabolomics profiles of primary chondrocytes in response to applied dynamic compression, this study provides insight into how OA chondrocytes respond to mechanical load. These results are consistent with increases in glycolytic energy utilization by mechanically induced signaling, and add substantial new data to a complex picture of how chondrocytes transduce mechanical loads.
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Affiliation(s)
- Donald L Zignego
- Department of Mechanical and Industrial Engineering, Montana State University, United States
| | - Jonathan K Hilmer
- Department of Chemistry and Biochemistry, Montana State University, United States
| | - Ronald K June
- Department of Mechanical and Industrial Engineering, Montana State University, United States; Department of Cell Biology and Neurosciences, Montana State University, United States; Department of Orthopaedics and Sports Medicine, University of Washington, United States.
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Farnsworth NL, Mead BE, Antunez LR, Palmer AE, Bryant SJ. Ionic osmolytes and intracellular calcium regulate tissue production in chondrocytes cultured in a 3D charged hydrogel. Matrix Biol 2014; 40:17-26. [DOI: 10.1016/j.matbio.2014.08.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Revised: 08/03/2014] [Accepted: 08/06/2014] [Indexed: 01/18/2023]
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Skaalure SC, Dimson SO, Pennington AM, Bryant SJ. Semi-interpenetrating networks of hyaluronic acid in degradable PEG hydrogels for cartilage tissue engineering. Acta Biomater 2014; 10:3409-20. [PMID: 24769116 DOI: 10.1016/j.actbio.2014.04.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 03/26/2014] [Accepted: 04/14/2014] [Indexed: 12/11/2022]
Abstract
Hydrolytically biodegradable poly(ethylene glycol) (PEG) hydrogels offer a promising platform for chondrocyte encapsulation and tuning degradation for cartilage tissue engineering, but offer no bioactive cues to encapsulated cells. This study tests the hypothesis that a semi-interpenetrating network of entrapped hyaluronic acid (HA), a bioactive molecule that binds cell surface receptors on chondrocytes, and crosslinked degradable PEG improves matrix synthesis by encapsulated chondrocytes. Degradation was achieved by incorporating oligo (lactic acid) segments into the crosslinks. The effects of HA molecular weight (MW) (2.9×10(4) and 2×10(6)Da) and concentration (0.5 and 5mgg(-1)) were investigated. Bovine chondrocytes were encapsulated in semi-interpenetrating networks and cultured for 4weeks. A steady release of HA was observed over the course of the study with 90% released by 4weeks. Incorporation of HA led to significantly higher cell numbers throughout the culture period. After 8days, HA increased collagen content per cell, increased aggrecan-positive cells, while decreasing the deposition of hypertrophic collagen X, but these effects were not sustained long term. Measuring total sulfated glycosaminoglycan (sGAG) and collagen content within the constructs and released to the culture medium after 4weeks revealed that total matrix synthesis was elevated by high concentrations of HA, indicating that HA stimulated matrix production although this matrix was not retained within the hydrogels. Matrix-degrading enzymes were elevated in the low-, but not the high-MW HA. Overall, incorporating high-MW HA into degrading hydrogels increased chondrocyte number and sGAG and collagen production, warranting further investigations to improve retention of newly synthesized matrix molecules.
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Affiliation(s)
- Stacey C Skaalure
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, USA; BioFrontiers Institute, University of Colorado, Boulder, CO 80309, USA
| | - Shash O Dimson
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, USA
| | - Ashley M Pennington
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, USA
| | - Stephanie J Bryant
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, USA; BioFrontiers Institute, University of Colorado, Boulder, CO 80309, USA; Materials Science and Engineering Program, University of Colorado, Boulder, CO 80309, USA.
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Mechanical loading: potential preventive and therapeutic strategy for osteoarthritis. J Am Acad Orthop Surg 2014; 22:465-6. [PMID: 24966253 PMCID: PMC5007862 DOI: 10.5435/jaaos-22-07-465] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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Jutila AA, Zignego DL, Hwang BK, Hilmer JK, Hamerly T, Minor CA, Walk ST, June RK. Candidate mediators of chondrocyte mechanotransduction via targeted and untargeted metabolomic measurements. Arch Biochem Biophys 2014; 545:116-23. [PMID: 24440608 DOI: 10.1016/j.abb.2014.01.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 01/10/2014] [Accepted: 01/11/2014] [Indexed: 11/30/2022]
Abstract
Chondrocyte mechanotransduction is the process by which cartilage cells transduce mechanical loads into biochemical and biological signals. Previous studies have identified several pathways by which chondrocytes transduce mechanical loads, yet a general understanding of which signals are activated and in what order remains elusive. This study was performed to identify candidate mediators of chondrocyte mechanotransduction using SW1353 chondrocytes embedded in physiologically stiff agarose. Dynamic compression was applied to cell-seeded constructs for 0-30min, followed immediately by whole-cell metabolite extraction. Metabolites were detected via LC-MS, and compounds of interest were identified via database searches. We found several metabolites which were statistically different between the experimental groups, and we report the detection of 5 molecules which are not found in metabolite databases of known compounds indicating potential novel molecules. Targeted studies to quantify the response of central energy metabolites to compression found a transient increase in the ratio of NADP+ to NADPH and a continual decrease in the ratio of GDP to GTP, suggesting a flux of energy into the TCA cycle. These data are consistent with the remodeling of cytoskeletal components by mechanically induced signaling, and add substantial new data to a complex picture of how chondrocytes transduce mechanical loads.
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Affiliation(s)
- Aaron A Jutila
- Department of Mechanical and Industrial Engineering, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States
| | - Donald L Zignego
- Department of Mechanical and Industrial Engineering, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States
| | - Bradley K Hwang
- Department of Mechanical and Industrial Engineering, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States
| | - Jonathan K Hilmer
- Department of Chemistry and Biochemistry, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States
| | - Timothy Hamerly
- Department of Chemistry and Biochemistry, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States
| | - Cody A Minor
- Department of Mechanical and Industrial Engineering, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States
| | - Seth T Walk
- Department of Immunology and Microbiology, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States
| | - Ronald K June
- Department of Cell Biology and Neuroscience, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States.
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Zignego DL, Jutila AA, Gelbke MK, Gannon DM, June RK. The mechanical microenvironment of high concentration agarose for applying deformation to primary chondrocytes. J Biomech 2013; 47:2143-8. [PMID: 24275437 DOI: 10.1016/j.jbiomech.2013.10.051] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 10/25/2013] [Accepted: 10/31/2013] [Indexed: 11/16/2022]
Abstract
Cartilage and chondrocytes experience loading that causes alterations in chondrocyte biological activity. In vivo chondrocytes are surrounded by a pericellular matrix with a stiffness of ~25-200kPa. Understanding the mechanical loading environment of the chondrocyte is of substantial interest for understanding chondrocyte mechanotransduction. The first objective of this study was to analyze the spatial variability of applied mechanical deformations in physiologically stiff agarose on cellular and sub-cellular length scales. Fluorescent microspheres were embedded in physiologically stiff agarose hydrogels. Microsphere positions were measured via confocal microscopy and used to calculate displacement and strain fields as a function of spatial position. The second objective was to assess the feasibility of encapsulating primary human chondrocytes in physiologically stiff agarose. The third objective was to determine if primary human chondrocytes could deform in high-stiffness agarose gels. Primary human chondrocyte viability was assessed using live-dead imaging following 24 and 72h in tissue culture. Chondrocyte shape was measured before and after application of 10% compression. These data indicate that (1) displacement and strain precision are ~1% and 6.5% respectively, (2) high-stiffness agarose gels can maintain primary human chondrocyte viability of >95%, and (3) compression of chondrocytes in 4.5% agarose can induce shape changes indicative of cellular compression. Overall, these results demonstrate the feasibility of using high-concentration agarose for applying in vitro compression to chondrocytes as a model for understanding how chondrocytes respond to in vivo loading.
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Affiliation(s)
- Donald L Zignego
- Department of Mechanical and Industrial Engineering, Montana State University, Bozeman, MT 59718-3800, USA
| | - Aaron A Jutila
- Department of Mechanical and Industrial Engineering, Montana State University, Bozeman, MT 59718-3800, USA
| | - Martin K Gelbke
- Bridger Orthopedic and Sports Medicine, Bozeman, MT 59715, USA
| | - Daniel M Gannon
- Bridger Orthopedic and Sports Medicine, Bozeman, MT 59715, USA
| | - Ronald K June
- Department of Mechanical and Industrial Engineering, Montana State University, Bozeman, MT 59718-3800, USA; Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59718-3800, USA.
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