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Merry K, Napier C, Waugh CM, Scott A. Foundational Principles and Adaptation of the Healthy and Pathological Achilles Tendon in Response to Resistance Exercise: A Narrative Review and Clinical Implications. J Clin Med 2022; 11:4722. [PMID: 36012960 PMCID: PMC9410084 DOI: 10.3390/jcm11164722] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/03/2022] [Accepted: 08/08/2022] [Indexed: 12/03/2022] Open
Abstract
Therapeutic exercise is widely considered a first line fundamental treatment option for managing tendinopathies. As the Achilles tendon is critical for locomotion, chronic Achilles tendinopathy can have a substantial impact on an individual's ability to work and on their participation in physical activity or sport and overall quality of life. The recalcitrant nature of Achilles tendinopathy coupled with substantial variation in clinician-prescribed therapeutic exercises may contribute to suboptimal outcomes. Further, loading the Achilles tendon with sufficiently high loads to elicit positive tendon adaptation (and therefore promote symptom alleviation) is challenging, and few works have explored tissue loading optimization for individuals with tendinopathy. The mechanism of therapeutic benefit that exercise therapy exerts on Achilles tendinopathy is also a subject of ongoing debate. Resultingly, many factors that may contribute to an optimal therapeutic exercise protocol for Achilles tendinopathy are not well described. The aim of this narrative review is to explore the principles of tendon remodeling under resistance-based exercise in both healthy and pathologic tissues, and to review the biomechanical principles of Achilles tendon loading mechanics which may impact an optimized therapeutic exercise prescription for Achilles tendinopathy.
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Affiliation(s)
- Kohle Merry
- Department of Physical Therapy, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
- Centre for Hip Health and Mobility, Vancouver, BC V5Z 1M9, Canada
| | - Christopher Napier
- Department of Physical Therapy, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
- Centre for Hip Health and Mobility, Vancouver, BC V5Z 1M9, Canada
| | - Charlie M. Waugh
- Department of Physical Therapy, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
- Centre for Hip Health and Mobility, Vancouver, BC V5Z 1M9, Canada
| | - Alex Scott
- Department of Physical Therapy, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
- Centre for Hip Health and Mobility, Vancouver, BC V5Z 1M9, Canada
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2
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Eekhoff JD, Abraham JA, Schott HR, Solon LF, Ulloa GE, Zellers JA, Cannon PC, Lake SP. Fascicular elastin within tendon contributes to the magnitude and modulus gradient of the elastic stress response across tendon type and species. Acta Biomater 2022; 163:91-105. [PMID: 35306182 DOI: 10.1016/j.actbio.2022.03.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/07/2022] [Accepted: 03/10/2022] [Indexed: 11/19/2022]
Abstract
Elastin, the main component of elastic fibers, has been demonstrated to significantly influence tendon mechanics using both elastin degradation studies and elastinopathic mouse models. However, it remains unclear how prior results differ between species and functionally distinct tendons and, in particular, how results translate to human tendon. Differences in function between fascicular and interfascicular elastin are also yet to be fully elucidated. Therefore, this study evaluated the quantity, structure, and mechanical contribution of elastin in functionally distinct tendons across species. Tendons with an energy-storing function had slightly more elastin content than tendons with a positional function, and human tendon had at least twice the elastin content of other species. While distinctions in the organization of elastic fibers between fascicles and the interfascicular matrix were observed, differences in structural arrangement of the elastin network between species and tendon type were limited. Mechanical testing paired with enzyme-induced elastin degradation was used to evaluate the contribution of elastin to tendon mechanics. Across all tendons, elastin degradation affected the elastic stress response by decreasing stress values while increasing the modulus gradient of the stress-strain curve. Only the contributions of elastin to viscoelastic properties varied between tendon type and species, with human tendon and energy-storing tendon being more affected. These data suggest that fascicular elastic fibers contribute to the tensile mechanical response of tendon, likely by regulating collagen engagement under load. Results add to prior findings and provide evidence for a more mechanistic understanding of the role of elastic fibers in tendon. STATEMENT OF SIGNIFICANCE: Elastin has previously been shown to influence the mechanical properties of tendon, and degraded or abnormal elastin networks caused by aging or disease may contribute to pain and an increased risk of injury. However, prior work has not fully determined how elastin contributes differently to tendons with varying functional demands, as well as within distinct regions of tendon. This study determined the effects of elastin degradation on the tensile elastic and viscoelastic responses of tendons with varying functional demands, hierarchical structures, and elastin content. Moreover, volumetric imaging and protein quantification were used to thoroughly characterize the elastin network in each distinct tendon. The results presented herein can inform tendon-specific strategies to maintain or restore native properties in elastin-degraded tissue.
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Affiliation(s)
- Jeremy D Eekhoff
- Department of Biomedical Engineering, Washington University in St. Louis, 1 Brookings Drive, MSC: 1185-208-125, St. Louis, MO 63130, United States
| | - James A Abraham
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, United States
| | - Hayden R Schott
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, United States
| | - Lorenzo F Solon
- Department of Biology, Washington University in St. Louis, United States
| | - Gabriella E Ulloa
- Department of Mechanical Engineering, Massachusetts Institute of Technology, United States
| | - Jennifer A Zellers
- Department of Physical Therapy, Washington University in St. Louis School of Medicine, United States
| | - Paul C Cannon
- Department of Mathematics, Brigham Young University - Idaho, United States
| | - Spencer P Lake
- Department of Biomedical Engineering, Washington University in St. Louis, 1 Brookings Drive, MSC: 1185-208-125, St. Louis, MO 63130, United States; Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, United States; Department of Orthopaedic Surgery, Washington University in St. Louis School of Medicine, , United States.
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3
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Lattouf R, Assoumou-Abroh A, Younes R, Lutomski D, Bassil J, Blanchet-Bardon C, Naaman N, Changotade S, Godeau G, Senni K. Inherited connective tissue diseases highlight macromolecular network interdependences in skin extracellular matrix: a histomorphometric study. J Histotechnol 2022; 45:66-76. [PMID: 35135439 DOI: 10.1080/01478885.2021.2024980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Mutation of just a single extracellular matrix protein, a receptor or enzyme involved in connective tissue metabolism is sufficient to cause systemic pathologies and failure of tissues that are subjected to strong mechanical stresses. Skin histological and computerized image analyses can provide a good qualitative and quantitative indication of these inherited connective tissue diseases. In this study, skin biopsies from young (10 to 25 years) and middle-aged patients (26 to 50 years) suffering from Ehlers-Danlos syndromes (EDS), Marfan syndrome (MS) or pseudoxanthoma elasticum (PXE) were studied after specific staining of both the collagen and elastic networks. Findings from the histomorphometric analyses conducted on skin sections of the patients with EDS, MS and PXE were compared to skin sections of healthy subjects from the same age groups. Our results show that both the collagen and the elastic networks were affected in all the studied pathological cases, but that the adverse changes to the elastic network in older patients were distinct from the physiological changes observed during aging process for healthy subjects. This degenerative process may be explained by an added phenomenon involving a general connective tissue proteolysis.
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Affiliation(s)
- Raed Lattouf
- Faculty of Dental Medicine, Saint Joseph University of Beirut, Beirut, Lebanon
| | - Antoine Assoumou-Abroh
- Department of Biology, Faculty of Dental Surgery, Université Félix Houphouët-Boigny, Abidjan, Ivory Coast
| | - Ronald Younes
- Faculty of Dental Medicine, Saint Joseph University of Beirut, Beirut, Lebanon
| | - Didier Lutomski
- Unité de Recherche en Ingénierie Tissulaire-URIT, Université Paris 13 dénommée Université Sorbonne Paris Nord, Bobigny, France
| | - Joseph Bassil
- Faculty of Dental Medicine, Saint Joseph University of Beirut, Beirut, Lebanon
| | | | - Nada Naaman
- Faculty of Dental Medicine, Saint Joseph University of Beirut, Beirut, Lebanon
| | - Sylvie Changotade
- Unité de Recherche en Ingénierie Tissulaire-URIT, Université Paris 13 dénommée Université Sorbonne Paris Nord, Bobigny, France
| | - Gaston Godeau
- Biochemistry Department, Dental School, Paris Descartes University, Montrouge, France
| | - Karim Senni
- Laboratoire EBInnov, Ecole de Biologie Industrielle-EBI, Cergy, France
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4
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Wu JP, Yang X, Wang Y, Swift B, Adamson R, Zheng Y, Zhang R, Zhong W, Chen F. High Resolution and Labeling Free Studying the 3D Microstructure of the Pars Tensa-Annulus Unit of Mice. Front Cell Dev Biol 2021; 9:720383. [PMID: 34692679 PMCID: PMC8532514 DOI: 10.3389/fcell.2021.720383] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/13/2021] [Indexed: 11/21/2022] Open
Abstract
Hearing loss is a serious illness affecting people’s normal life enormously. The acoustic properties of a tympanic membrane play an important role in hearing, and highly depend on its geometry, composition, microstructure and connection to the surrounding annulus. While the conical geometry of the tympanic membrane is critical to the sound propagation in the auditory system, it presents significant challenges to the study of the 3D microstructure of the tympanic membrane using traditional 2D imaging techniques. To date, most of our knowledge about the 3D microstructure and composition of tympanic membranes is built from 2D microscopic studies, which precludes an accurate understanding of the 3D microstructure, acoustic behaviors and biology of the tissue. Although the tympanic membrane has been reported to contain elastic fibers, the morphological characteristic of the elastic fibers and the spatial arrangement of the elastic fibers with the predominant collagen fibers have not been shown in images. We have developed a 3D imaging technique for the three-dimensional examination of the microstructure of the full thickness of the tympanic membranes in mice without requiring tissue dehydration and stain. We have also used this imaging technique to study the 3D arrangement of the collagen and elastic fibrillar network with the capillaries and cells in the pars tensa-annulus unit at a status close to the native. The most striking findings in the study are the discovery of the 3D form of the elastic and collagen network, and the close spatial relationships between the elastic fibers and the elongated fibroblasts in the tympanic membranes. The 3D imaging technique has enabled to show the 3D waveform contour of the collagen and elastic scaffold in the conical tympanic membrane. Given the close relationship among the acoustic properties, composition, 3D microstructure and geometry of tympanic membranes, the findings may advance the understanding of the structure—acoustic functionality of the tympanic membrane. The knowledge will also be very helpful in the development of advanced cellular therapeutic technologies and 3D printing techniques to restore damaged tympanic membranes to a status close to the native.
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Affiliation(s)
- Jian-Ping Wu
- Academy of Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, China.,Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Xiaojie Yang
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Yilin Wang
- Core Research Facilities, Southern University of Science and Technology, Shenzhen, China
| | - Ben Swift
- College of Computing, Australian National University, Canberra, ACT, Australia
| | - Robert Adamson
- School of Biomedical Engineering, Electrical and Computer Engineering, Dalhousie University, Halifax, NS, Canada
| | - Yongchang Zheng
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Rongli Zhang
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Science, School of Medicine, South China University of Technology, Guangzhou, China
| | - Wen Zhong
- School of Mechanical Engineering and Automation, Xihua University, Chengdu, China
| | - Fangyi Chen
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China.,Department of Biology, Brain Research Centre, Southern University of Science and Technology, Shenzhen, China
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5
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Lloyd D. The future of in-field sports biomechanics: wearables plus modelling compute real-time in vivo tissue loading to prevent and repair musculoskeletal injuries. Sports Biomech 2021:1-29. [PMID: 34496728 DOI: 10.1080/14763141.2021.1959947] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 07/20/2021] [Indexed: 01/13/2023]
Abstract
This paper explores the use of biomechanics in identifying the mechanistic causes of musculoskeletal tissue injury and degeneration. It appraises how biomechanics has been used to develop training programmes aiming to maintain or recover tissue health. Tissue health depends on the functional mechanical environment experienced by tissues during daily and rehabilitation activities. These environments are the result of the interactions between tissue motion, loading, biology, and morphology. Maintaining health of and/or repairing musculoskeletal tissues requires targeting the "ideal" in vivo tissue mechanics (i.e., loading and deformation), which may be enabled by appropriate real-time biofeedback. Recent research shows that biofeedback technologies may increase their quality and effectiveness by integrating a personalised neuromusculoskeletal modelling driven by real-time motion capture and medical imaging. Model personalisation is crucial in obtaining physically and physiologically valid predictions of tissue biomechanics. Model real-time execution is crucial and achieved by code optimisation and artificial intelligence methods. Furthermore, recent work has also shown that laboratory-based motion capture biomechanical measurements and modelling can be performed outside the laboratory with wearable sensors and artificial intelligence. The next stage is to combine these technologies into well-designed easy to use products to guide training to maintain or recover tissue health in the real-world.
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Affiliation(s)
- David Lloyd
- School of Health Sciences and Social Work, Griffith Centre of Biomedical and Rehabilitation Engineering (GCORE), in the Menzies Health Institute Queensland and Advanced Design and Prototyping Technologies Institute, Griffith University, Australia
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6
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Abstract
As the extracellular matrix protein, elastin is a crucial component of connective tissue in life. It is responsible for the structural integrity and function of tissues undergoing reversible extensibility or deformability, even though it may make up only a small percentage of a tissue. The structure stability, elastic resilience, bioactivity, and ability of self-assembly make elastin a highly desirable candidate for the fabrication of biomaterials. Elastin's properties mainly depend on their special structure. As elastin can be obtained by the assembly and cross-linking of its soluble precursor, tropoelastin. This chapter centers on introducing the structure of those two materials.
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7
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Yang Y, Wu Y, Zhou K, Wu D, Yao X, Heng BC, Zhou J, Liu H, Ouyang H. Interplay of Forces and the Immune Response for Functional Tendon Regeneration. Front Cell Dev Biol 2021; 9:657621. [PMID: 34150755 PMCID: PMC8213345 DOI: 10.3389/fcell.2021.657621] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 04/26/2021] [Indexed: 01/11/2023] Open
Abstract
Tendon injury commonly occurs during sports activity, which may cause interruption or rapid decline in athletic career. Tensile strength, as one aspect of tendon biomechanical properties, is the main parameter of tendon function. Tendon injury will induce an immune response and cause the loss of tensile strength. Regulation of mechanical forces during tendon healing also changes immune response to improve regeneration. Here, the effects of internal/external forces and immune response on tendon regeneration are reviewed. The interaction between immune response and internal/external forces during tendon regeneration is critically examined and compared, in relation to other tissues. In conclusion, it is essential to maintain a fine balance between internal/external forces and immune response, to optimize tendon functional regeneration.
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Affiliation(s)
- Yuwei Yang
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, and Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Yicong Wu
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, and Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Ke Zhou
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, and Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Dongmei Wu
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, and Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Xudong Yao
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, and Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Boon Chin Heng
- Central Laboratories, School of Stomatology, Peking University, Beijing, China
| | - Jing Zhou
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, and Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Hua Liu
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, and Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Hongwei Ouyang
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, and Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
- Department of Sports Medicine, Zhejiang University School of Medicine, Hangzhou, China
- China Orthopedic Regenerative Medicine Group (CORMed), Hangzhou, China
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8
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Liu J, Xu MY, Wu J, Zhang H, Yang L, Lun DX, Hu YC, Liu B. Picrosirius-Polarization Method for Collagen Fiber Detection in Tendons: A Mini-Review. Orthop Surg 2021; 13:701-707. [PMID: 33689233 PMCID: PMC8126917 DOI: 10.1111/os.12627] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 01/14/2020] [Accepted: 01/14/2020] [Indexed: 12/31/2022] Open
Abstract
Although the structure and composition of collagen have been studied by polarized light microscopy since the early 19th century, many studies and reviews have paid little or no attention to the morphological problems of histopathological diagnosis. The morphology of collagen fibers is critical in guiding mechanical and biological properties in both normal and pathological tendons. Highlighting the organization and spatial distribution of tendon‐containing collagen fibers can be very useful for visualizing a tendon's ultrastructure, biochemical and indirect mechanical properties, which benefits other researchers and clinicians. Picrosirius red (PSR) staining, relying on the birefringence of collagen fibers, is one of the best understood histochemical methods that can highly and specifically underline fibers better than other common staining techniques when combined with polarized light microscopy (PLM). Polarized light microscopy provides complementary information about collagen fibers, such as orientation, type and spatial distribution, which is important for a comprehensive assessment of collagen alteration in a tendon. Here, this brief review serves as a simplistic and important primer to research developments in which differential staining of collagen types by the Picrosirius‐polarization method is increasing in diverse studies of the medical field, mainly in the assessment of the morphology, spatial distribution, and content of collagen in tendons.
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Affiliation(s)
- Jie Liu
- Tianjin Medical University, Tianjin, China
| | | | - Jing Wu
- Center for Medical Device Evaluation NMPA, Beijing, China
| | | | - Li Yang
- Tianjin Hospital, Tianjin, China
| | | | | | - Bin Liu
- Center for Medical Device Evaluation NMPA, Beijing, China
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9
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Eekhoff JD, Steenbock H, Berke IM, Brinckmann J, Yanagisawa H, Wagenseil JE, Lake SP. Dysregulated assembly of elastic fibers in fibulin-5 knockout mice results in a tendon-specific increase in elastic modulus. J Mech Behav Biomed Mater 2021; 113:104134. [PMID: 33045519 PMCID: PMC8146012 DOI: 10.1016/j.jmbbm.2020.104134] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/29/2020] [Accepted: 10/04/2020] [Indexed: 12/15/2022]
Abstract
Elastic fiber assembly is coordinated in part by fibulin-5, a matricellular protein. When fibulin-5 is not available to guide elastogenesis, elastin forms into disconnected globules instead of the dense elastic fiber core found in healthy tissues. Despite the growing evidence for a significant role of elastic fibers in tendon mechanics and the clinical relevance to cutis laxa, a human disease which can be caused by a mutation in the gene encoding fibulin-5, it is unknown how malformed elastic fibers affect tendon function. Therefore, this study investigated the effects of dysregulated elastic fiber assembly in tendons from fibulin-5 knockout mice in comparison to wild-type controls. Due to evidence for a more prominent role of elastic fibers in tendons with higher functional demands, both the energy-storing Achilles tendon and the more positional tibialis anterior tendon were evaluated. The linear modulus of knockout Achilles tendons was increased compared to controls, yet there was no discernible change in mechanical properties of the tibialis anterior tendon across genotypes. Transmission electron microscopy confirmed the presence of malformed elastic fibers in knockout tendons while no other changes to tendon composition or structure were found. The mechanism behind the increase in linear modulus in fibulin-5 knockout Achilles tendons may be greater collagen engagement due to decreased regulation of strain-induced structural reorganization. These findings support the theory of a significant, functionally distinct role of elastic fibers in tendon mechanics.
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Affiliation(s)
- Jeremy D Eekhoff
- Department of Biomedical Engineering, Washington University in St. Louis, USA
| | - Heiko Steenbock
- Institute of Virology and Cell Biology, University of Lübeck, Germany
| | - Ian M Berke
- Department of Biomedical Engineering, Washington University in St. Louis, USA
| | - Jürgen Brinckmann
- Institute of Virology and Cell Biology, University of Lübeck, Germany; Department of Dermatology, University of Lübeck, Germany
| | - Hiromi Yanagisawa
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance, University of Tsukuba, Japan
| | - Jessica E Wagenseil
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, USA
| | - Spencer P Lake
- Department of Biomedical Engineering, Washington University in St. Louis, USA; Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, USA; Department of Orthopaedic Surgery, Washington University in St. Louis, USA.
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10
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Xiao S, Shao Y, Li B, Feng XQ. A micromechanical model of tendon and ligament with crimped fibers. J Mech Behav Biomed Mater 2020; 112:104086. [DOI: 10.1016/j.jmbbm.2020.104086] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/22/2020] [Accepted: 09/08/2020] [Indexed: 12/14/2022]
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11
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Hill JR, Eekhoff JD, Brophy RH, Lake SP. Elastic fibers in orthopedics: Form and function in tendons and ligaments, clinical implications, and future directions. J Orthop Res 2020; 38:2305-2317. [PMID: 32293749 PMCID: PMC7572591 DOI: 10.1002/jor.24695] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 03/21/2020] [Accepted: 04/11/2020] [Indexed: 02/04/2023]
Abstract
Elastic fibers are an essential component of the extracellular matrix of connective tissues. The focus of both clinical management and scientific investigation of elastic fiber disorders has centered on the cardiovascular manifestations due to their significant impact on morbidity and mortality. As such, the current understanding of the orthopedic conditions experienced by these patients is limited. The musculoskeletal implications of more subtle elastic fiber abnormalities, whether due to allelic variants or age-related tissue degeneration, are also not well understood. Recent advances have begun to uncover the effects of elastic fiber deficiency on tendon and ligament biomechanics; future research must further elucidate mechanisms governing the role of elastic fibers in these tissues. The identification of population-based genetic variations in elastic fibers will also be essential. Minoxidil administration, modulation of protein expression with micro-RNA molecules, and direct injection of recombinant elastic fiber precursors have demonstrated promise for therapeutic intervention, but further work is required prior to consideration for orthopedic clinical application. This review provides an overview of the role of elastic fibers in musculoskeletal tissue, summarizes current knowledge of the orthopedic manifestations of elastic fiber abnormalities, and identifies opportunities for future investigation and clinical application.
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Affiliation(s)
- J. Ryan Hill
- Department of Orthopaedic Surgery, Washington University in St. Louis, 425 S. Euclid Avenue, Suite 5505, St. Louis, MO 63110
| | - Jeremy D. Eekhoff
- Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130
| | - Robert H. Brophy
- Department of Orthopaedic Surgery, Washington University in St. Louis, 425 S. Euclid Avenue, Suite 5505, St. Louis, MO 63110
| | - Spencer P. Lake
- Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130,Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130
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12
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Tran PHT, Skrba T, Wondimu E, Galatioto G, Svensson RB, Olesen AT, Mackey AL, Magnusson SP, Ramirez F, Kjaer M. The influence of fibrillin-1 and physical activity upon tendon tissue morphology and mechanical properties in mice. Physiol Rep 2020; 7:e14267. [PMID: 31724332 PMCID: PMC6854111 DOI: 10.14814/phy2.14267] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 09/15/2019] [Accepted: 09/17/2019] [Indexed: 01/26/2023] Open
Abstract
Fibrillin‐1 mutations cause pathological changes in connective tissue that constitute the complex phenotype of Marfan syndrome. In this study, we used fibrillin‐1 hypomorphic and haploinsufficient mice (Fbn1mgr/mgR and Fbn1+/− mice, respectively) to investigate the impact of fibrillin‐1 deficiency alone or in combination with regular physical activity on tendon tissue morphology and mechanical properties. Morphological and biomechanical analyses revealed that Fbn1mgr/mgR but not Fbn1+/− mice displayed smaller tendons with physical properties that were unremarkable when normalized to tendon size. Fbn1mgR/mgR mice (n = 43) Fbn1+/−mice (n = 27) and wild‐type mice (WT, n = 25) were randomly assigned to either control cage conditions (n = 54) or to a running on a running wheel for 4 weeks (n = 41). Both fibrillin‐1‐deficient mice ran voluntarily on the running wheel in a manner similar to WT mice (3–4 km/24 h). Regular exercise did not mitigate aneurysm progression in Fbn1mgR/mgR mice (P < 0.05) as evidenced by unmodified median survival. In spite of the smaller size, tendons of fibrillin‐1‐deficient mice subjected to regular exercise showed no evidence of overt histopathological changes or tissue overload. We therefore concluded that lack of optimal fibrillin‐1 synthesis leads to a down regulation of integrated tendon formation, rather than to a loss of tendon quality, which also implies that fibrillin‐1 deficiency in combination with exercise is not a suitable animal model for studying the development of tendon overuse (tendinopathy).
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Affiliation(s)
- Peter H T Tran
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York.,Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark.,Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tanja Skrba
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York.,Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark.,Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Elisabeth Wondimu
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Giuseppina Galatioto
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - René Brüggebusch Svensson
- Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark.,Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Physical and Occupational Therapy, Bispebjerg Hospital, Copenhagen, Denmark
| | - Annesofie T Olesen
- Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark.,Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Abigail L Mackey
- Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark.,Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - S Peter Magnusson
- Department of Physical and Occupational Therapy, Bispebjerg Hospital, Copenhagen, Denmark
| | - Francesco Ramirez
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Michael Kjaer
- Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark.,Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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13
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Wu YT, Wu YT, Huang TC, Su FC, Jou IM, Wu CC. Sequential inflammation model for Achilles tendinopathy by elastin degradation with treadmill exercise. J Orthop Translat 2020; 23:113-121. [PMID: 32642426 PMCID: PMC7322491 DOI: 10.1016/j.jot.2020.03.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 02/28/2020] [Accepted: 03/05/2020] [Indexed: 12/12/2022] Open
Abstract
Background & objective Tendinopathy is a tendon disease with abnormal mechanical loading to induce chronic repetitive injury. However, lack of a comparable animal model to demonstrate clinical progressions has hindered the understanding of anatomical and pathological changes. The major extracellular matrix (ECM) in the tendon consists of abundant type I collagen (COL) and minimal amount of elastin (ELN). Methods To study the ECM breakdown and inflammation, rat Achilles tendon was harvested and ex vivo incubated with specific enzymes of elastase (ELNase) or collagenase (COLase). Results The ELNase broke down ELN, loosened the tendon structure, and increased the COL composition. Increases in cyclooxygenase-2 expression levels in tenocytes were revealed to induce inflammation with either ELNase or COLase. However, incubation of COLase for 12 hours severely digested the tendon. To create a proper ELN degradation in rats, the present study used high-frequency ultrasound to guide the injection of ELNase at the paratendon tissue of the Achilles tendon. The effect of mechanically triggered inflammatory responses was investigated by applying treadmill exercise (15 m/min for 20 min per day). After ELNase injection for 14 and 28 days, a significant loss of ELN was observed, and exercise further facilitated the pathological transition of COL. The dynamics of inflammatory cell recruitments was revealed by specific staining of CD-11b (neutrophils) and CD-68 (macrophage) after in vivo injection of ELNase or COLase for 1, 3, 7, 14, and 28 days. The combination of ELNase and exercise caused early recruitment of neutrophil on day 1 and sequential expression of macrophage on day 7 in peritendinous tissue. Conclusion These results suggested that ELN degradation with repetitive mechanical loading may present a suitable model for the pathogenesis of tendinopathy. The Translational potential of this article This discover the role of elastin degradation in tendinopathy and the interaction of exercise in the histological changes. The established the pathological model mimicking the pathogenesis to the human disease by injecting the elastase using ultrasound guidance and then applying treadmill exercise. The loss of elastin and change of collagen composition in clinical tendinopathy samples were observed in the rats. In addition, the sequential inflammation cascades were observed in the histological outcomes with combination of elastase injection and treadmill exercise. Thus, this model may be used to test the clinical treatment of tendinopathy in different stages.
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Affiliation(s)
- Yi-Ting Wu
- Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Taiwan.,Department of Nursing, Tzu Hui Institute of Technology, Taiwan
| | - Yen-Ting Wu
- Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Taiwan
| | - Tzu-Chieh Huang
- Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Taiwan
| | - Fong-Chin Su
- Department of Biomedical Engineering, National Cheng Kung University, Taiwan
| | - I-Ming Jou
- Department of Orthopedics, National Cheng Kung University Hospital, Taiwan.,Department of Orthopedics, E-Da Hospital, Taiwan
| | - Chia-Ching Wu
- Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Taiwan.,Department of Biomedical Engineering, National Cheng Kung University, Taiwan.,International Center for Wound Repair and Regeneration, National Cheng Kung University, Taiwan
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14
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Hadate S, Takahashi N, Kametani K, Iwasaki T, Hasega Y, Tangkawattana P, Kawasaki T, Ueda H, Hosotani M, Watanabe T. Ultrastructural study of the three-dimensional tenocyte network in newly hatched chick Achilles tendons using serial block face-scanning electron microscopy. J Vet Med Sci 2020; 82:948-954. [PMID: 32418945 PMCID: PMC7399303 DOI: 10.1292/jvms.20-0120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The lateral cytoplasmic processes of tenocytes extend to form three-dimensional network surrounding collagen fibers. It is unknown whether connections between two cytoplasmic
processes involve overlapping of the processes or merely surface contact. In this study, the two-dimensional and three-dimensional structure of tenocytes in the Achilles tendons of
the newly hatched chicks were studied using transmission electron microscopy and serial block face-scanning electron microscopy. Observation of the two-dimensional structures
revealed various forms of cellular connections, including connections between the cytoplasmic processes of adjacent tenocytes and between the cytoplasmic process of tenocytes and
fibroblasts. Three-dimensional observation showed spike-like cytoplasmic processes extending from one tenocyte that interlocked with cytoplasmic processes from other tenocytes.
Cytoplasmic processes from each tenocyte within the chick tendons interlocked to ensure a tight cell-to-cell connection around growing collagen fibers. A cellular network formed by
these cytoplasmic processes surrounds each collagen fiber. Cell-cell junctions, which were suggested to be gap junctions, observed at sites of cytoplasmic process overlap most
likely represent the major route for communication between tenocytes associated with fibroblasts, enabling vital signals important for maintaining the cell and tendon integrity to
be transmitted.
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Affiliation(s)
- Shu Hadate
- Laboratory of Veterinary Anatomy, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
| | - Naoki Takahashi
- Laboratory of Veterinary Anatomy, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
| | - Kiyokazu Kametani
- Laboratory of Veterinary Anatomy, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
| | - Tomohito Iwasaki
- Department of Food Science and Human Wellness, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
| | - Yasuhiro Hasega
- Department of Food Science and Human Wellness, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
| | | | - Takeshi Kawasaki
- Research Office Concerning the Health of Humans and Birds, Abashiri, Hokkaido 099-3119, Japan
| | - Hiromi Ueda
- Laboratory of Veterinary Anatomy, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
| | - Marina Hosotani
- Laboratory of Veterinary Anatomy, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
| | - Takafumi Watanabe
- Laboratory of Veterinary Anatomy, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
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15
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Durgam S, Singh B, Cole SL, Brokken MT, Stewart M. Quantitative Assessment of Tendon Hierarchical Structure by Combined Second Harmonic Generation and Immunofluorescence Microscopy. Tissue Eng Part C Methods 2020; 26:253-262. [PMID: 32228165 DOI: 10.1089/ten.tec.2020.0032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Histological evaluation of healing tendons is primarily focused on monitoring restoration of longitudinal collagen alignment, although the elastic property of energy-storing flexor tendons is largely attributed to interfascicular sliding facilitated by the interfascicular matrix (IFM). The objectives of this study were to explore the utility of second harmonic generation (SHG) imaging to objectively assess cross-sectional tendon fascicle architecture, to combine SHG microscopy with elastin immunofluorescence to assess the ultrastructure of collagen and elastin in longitudinal and transverse sections, and lastly, to quantify changes in IFM elastin and fascicle collagen alignment of normal and collagenase-injured flexor tendons. Paraffin-embedded transverse and longitudinal histological sections (10-μm thickness) derived from normal and collagenase-injured (6- and 16-week time-points) equine superficial digital flexor tendons were de-paraffinized, treated with Tris EDTA at 80°C for epitope retrieval, and incubated with mouse monoclonal anti-elastin antibody (1:100 dilution) overnight. Anti-mouse IgG Alexa Flour 546 secondary antibody was applied, and sections were mounted with ProLong Gold reagent with 4',6-diamidino-2-phenylindole (DAPI). Nuclei (DAPI) and elastin (Alexa Fluor 546) signals were captured by using standard confocal imaging with 405 and 543 nm excitation wavelengths, respectively. The SHG signal was captured by using a tunable Ti:Sapphire laser tuned to 950 nm to visualize type I collagen. Quantitative measurements of fascicle cross-sectional area (CSA), IFM thickness in transverse SHG-DAPI merged z-stacks, fascicle/IFM elastin area fraction (%), and elastin-collagen alignment in longitudinal SHG-elastin merged z-stacks were conducted by using ImageJ software. Using this methodology, fascicle CSA, IFM thickness, and IFM elastin area fraction (%) at 6 weeks (∼2.25-fold; ∼2.8-fold; 60% decrease; p < 0.001) and 16 weeks (∼2-fold; ∼1.5-fold; 70% decrease; p < 0.001) after collagenase injection, respectively, were found to be significantly different from normal tendon. IFM elastin and fascicle collagen alignment characterized via fast Fourier transform (FFT) frequency plots at 16 weeks demonstrated that collagen re-alignment was more advanced than that of elastin. The integration of SHG-derived quantitative measurements in transverse and longitudinal tendon sections supports comprehensive assessment of tendon structure. Our findings demonstrate the importance of including IFM and non-collagenous proteins in tendon histological evaluations, tasks that can be effectively carried out by using SHG and immunofluorescence microscopy. Impact statement This work demonstrated that second harmonic generation microscopy in conjunction with elastin immunofluorescence provided a comprehensive assessment of multiscale structural re-organization in healing tendon than when restricted to longitudinal collagen fiber alignment alone. Utilizing this approach for tendon histomorphometry is ideal not only to improve our understanding of hierarchical structural changes that occur after tendon injury and during remodeling but also to monitor the efficacy of therapeutic approaches.
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Affiliation(s)
- Sushmitha Durgam
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Benjamin Singh
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Sara L Cole
- Campus Microscopy Imaging Facility, The Ohio State University, Columbus, Ohio, USA
| | - Matthew T Brokken
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Matthew Stewart
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, Illinois, USA
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16
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No YJ, Castilho M, Ramaswamy Y, Zreiqat H. Role of Biomaterials and Controlled Architecture on Tendon/Ligament Repair and Regeneration. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1904511. [PMID: 31814177 DOI: 10.1002/adma.201904511] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 11/10/2019] [Indexed: 06/10/2023]
Abstract
Engineering synthetic scaffolds to repair and regenerate ruptured native tendon and ligament (T/L) tissues is a significant engineering challenge due to the need to satisfy both the unique biological and biomechanical properties of these tissues. Long-term clinical outcomes of synthetic scaffolds relying solely on high uniaxial tensile strength are poor with high rates of implant rupture and synovitis. Ideal biomaterials for T/L repair and regeneration need to possess the appropriate biological and biomechanical properties necessary for the successful repair and regeneration of ruptured tendon and ligament tissues.
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Affiliation(s)
- Young Jung No
- Biomaterials and Tissue Engineering Research Unit, School of Biomedical Engineering, University of Sydney, Sydney, NSW, 2006, Australia
- Australian Research Council Training Centre for Innovative BioEngineering, Sydney, NSW, 2006, Australia
| | - Miguel Castilho
- Department of Orthopedics, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
- Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands
| | - Yogambha Ramaswamy
- Biomaterials and Tissue Engineering Research Unit, School of Biomedical Engineering, University of Sydney, Sydney, NSW, 2006, Australia
- Australian Research Council Training Centre for Innovative BioEngineering, Sydney, NSW, 2006, Australia
| | - Hala Zreiqat
- Biomaterials and Tissue Engineering Research Unit, School of Biomedical Engineering, University of Sydney, Sydney, NSW, 2006, Australia
- Australian Research Council Training Centre for Innovative BioEngineering, Sydney, NSW, 2006, Australia
- Radcliffe Institute for Advanced Study, Harvard University, Cambridge, MA, 02138, USA
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17
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Taye N, Karoulias SZ, Hubmacher D. The "other" 15-40%: The Role of Non-Collagenous Extracellular Matrix Proteins and Minor Collagens in Tendon. J Orthop Res 2020; 38:23-35. [PMID: 31410892 PMCID: PMC6917864 DOI: 10.1002/jor.24440] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 08/02/2019] [Indexed: 02/04/2023]
Abstract
Extracellular matrix (ECM) determines the physiological function of all tissues, including musculoskeletal tissues. In tendon, ECM provides overall tissue architecture, which is tailored to match the biomechanical requirements of their physiological function, that is, force transmission from muscle to bone. Tendon ECM also constitutes the microenvironment that allows tendon-resident cells to maintain their phenotype and that transmits biomechanical forces from the macro-level to the micro-level. The structure and function of adult tendons is largely determined by the hierarchical organization of collagen type I fibrils. However, non-collagenous ECM proteins such as small leucine-rich proteoglycans (SLRPs), ADAMTS proteases, and cross-linking enzymes play critical roles in collagen fibrillogenesis and guide the hierarchical bundling of collagen fibrils into tendon fascicles. Other non-collagenous ECM proteins such as the less abundant collagens, fibrillins, or elastin, contribute to tendon formation or determine some of their biomechanical properties. The interfascicular matrix or endotenon and the outer layer of tendons, the epi- and paratenon, includes collagens and non-collagenous ECM proteins, but their function is less well understood. The ECM proteins in the epi- and paratenon may provide the appropriate microenvironment to maintain the identity of distinct tendon cell populations that are thought to play a role during repair processes after injury. The aim of this review is to provide an overview of the role of non-collagenous ECM proteins and less abundant collagens in tendon development and homeostasis. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:23-35, 2020.
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Affiliation(s)
- Nandaraj Taye
- Leni & Peter W. May Department of Orthopaedics, Orthopaedic Research LaboratoriesIcahn School of Medicine at Mt. SinaiNew York New York 10029
| | - Stylianos Z. Karoulias
- Leni & Peter W. May Department of Orthopaedics, Orthopaedic Research LaboratoriesIcahn School of Medicine at Mt. SinaiNew York New York 10029
| | - Dirk Hubmacher
- Leni & Peter W. May Department of Orthopaedics, Orthopaedic Research LaboratoriesIcahn School of Medicine at Mt. SinaiNew York New York 10029
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18
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Vetri V, Dragnevski K, Tkaczyk M, Zingales M, Marchiori G, Lopomo NF, Zaffagnini S, Bondi A, Kennedy JA, Murray DW, Barrera O. Advanced microscopy analysis of the micro-nanoscale architecture of human menisci. Sci Rep 2019; 9:18732. [PMID: 31822796 PMCID: PMC6904744 DOI: 10.1038/s41598-019-55243-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 11/13/2019] [Indexed: 12/05/2022] Open
Abstract
The complex inhomogeneous architecture of the human meniscal tissue at the micro and nano scale in the absence of artefacts introduced by sample treatments has not yet been fully revealed. The knowledge of the internal structure organization is essential to understand the mechanical functionality of the meniscus and its relationship with the tissue’s complex structure. In this work, we investigated human meniscal tissue structure using up-to-date non-invasive imaging techniques, based on multiphoton fluorescence and quantitative second harmonic generation microscopy complemented with Environmental Scanning Electron Microscopy measurements. Observations on 50 meniscal samples extracted from 6 human menisci (3 lateral and 3 medial) revealed fundamental features of structural morphology and allowed us to quantitatively describe the 3D organisation of elastin and collagen fibres bundles. 3D regular waves of collagen bundles are arranged in “honeycomb-like” cells that are comprised of pores surrounded by the collagen and elastin network at the micro-scale. This type of arrangement propagates from macro to the nanoscale.
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Affiliation(s)
- V Vetri
- Università degli Studi di Palermo, Palermo, Italy
| | | | | | - M Zingales
- Università degli Studi di Palermo, Palermo, Italy
| | - G Marchiori
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Biomeccanica e Innovazione Tecnologica, Bologna, Italy
| | - N F Lopomo
- Università degli Studi of Brescia, Brescia, Italy
| | - S Zaffagnini
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Biomeccanica e Innovazione Tecnologica, Bologna, Italy
| | - A Bondi
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Biomeccanica e Innovazione Tecnologica, Bologna, Italy
| | | | | | - O Barrera
- University of Oxford, Oxford, UK. .,University of Luxembourg, Luxembourg, Luxembourg. .,Oxford Brookes University, Oxford, UK.
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19
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BOYANICH R, BECKER T, CHEN F, KIRK TB, ALLISON G, WU J. Application of confocal, SHG and atomic force microscopy for characterizing the structure of the most superficial layer of articular cartilage. J Microsc 2019; 275:159-171. [DOI: 10.1111/jmi.12824] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 06/29/2019] [Accepted: 07/03/2019] [Indexed: 01/19/2023]
Affiliation(s)
- R. BOYANICH
- School of Civil and Mechanical EngineeringCurtin University Perth Western Australia Australia
| | - T. BECKER
- School of Molecular and Life Sciences/Curtin Institute for Functional Molecules and InterfacesCurtin University Perth Western Australia Australia
| | - F. CHEN
- Department of Biomedical EngineeringSouthern University of Science and Technology (SUSTech) Shenzhen China
| | - T. B. KIRK
- School of Civil and Mechanical EngineeringCurtin University Perth Western Australia Australia
| | - G. ALLISON
- Research Office at CurtinCurtin University Perth Western Australia Australia
| | - J.‐P. WU
- Academy of Advanced Interdisciplinary StudiesSouthern University of Science and Technology (SUSTech) Shenzhen China
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20
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Skalec A, Janeczek M, Czerski A. Anatomy and histology of the rabbit common calcanean tendon. Anat Histol Embryol 2019; 48:466-475. [PMID: 31347200 DOI: 10.1111/ahe.12468] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/20/2019] [Accepted: 06/12/2019] [Indexed: 11/28/2022]
Abstract
Despite the great progress in the field of tendon injuries and chronic tendinopathies in recent years, treatment of these conditions is still challenging. Research utilising animal models is crucial for further advancement in tendon research, with the rabbit being a commonly used species in this field. The objective of the present study was to comprehensively describe the macro- and microanatomy of the common calcanean tendon (tendo Achillei), together with associated structures. Eight female New Zealand rabbits were subjected to anatomical dissection and histologic analysis, revealing significant species-specific features. The soleus muscle presented a thin, spindle shape with no tendon of insertion and attached directly to the lateral gastrocnemius muscle. Therefore, it does not contribute to the formation of the common calcanean tendon. The calcaneal tendon of the semitendinosus muscle was identified as a strong tendinous band at the medial side of the medial gastrocnemius muscle and the superficial digital flexor muscle and tendon distally. The saphenous artery was accompanied by the medial saphenous vein and characteristic accessory medial saphenous vein. The complex structure of the paratendinous connective tissue is described, with the paratenon being contiguous with the epitenon of the individual tendons and epimysium of associated muscles. At the level of the calcaneal tuber, the retromalleolar fat pad was identified, adhering to the cranial surface of the conjoint gastrocnemius tendon. Histologic studies confirmed the presence of the subtendinous calcaneal bursa of superficial digital flexor tendon and the bursa of calcaneal tendon.
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Affiliation(s)
- Aleksandra Skalec
- Department of Animal Physiology and Biostructure, Division of Animal Anatomy, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Maciej Janeczek
- Department of Animal Physiology and Biostructure, Division of Animal Anatomy, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Albert Czerski
- Department of Animal Physiology and Biostructure, Division of Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
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21
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Almeida H, Domingues RMA, Mithieux SM, Pires RA, Gonçalves AI, Gómez-Florit M, Reis RL, Weiss AS, Gomes ME. Tropoelastin-Coated Tendon Biomimetic Scaffolds Promote Stem Cell Tenogenic Commitment and Deposition of Elastin-Rich Matrix. ACS APPLIED MATERIALS & INTERFACES 2019; 11:19830-19840. [PMID: 31088069 DOI: 10.1021/acsami.9b04616] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Tendon tissue engineering strategies that recreate the biophysical and biochemical native microenvironment have a greater potential to achieve regeneration. Here, we developed tendon biomimetic scaffolds using mechanically competent yarns of poly-ε-caprolactone, chitosan, and cellulose nanocrystals to recreate the inherent tendon hierarchy from a nano-to-macro scale. These were then coated with tropoelastin (TROPO) through polydopamine (PDA) linking, to mimic the native extracellular matrix (ECM) composition and elasticity. Both PDA and TROPO coatings decreased surface stiffness without masking the underlying substrate. We found that human adipose-derived stem cells (hASCs) seeded onto these TROPO biomimetic scaffolds more rapidly acquired their spindle-shape morphology and high aspect ratio characteristic of tenocytes. Immunocytochemistry shows that the PDA and TROPO-coated surfaces boosted differentiation of hASCs toward the tenogenic lineage, with sustained expression of the tendon-related markers scleraxis and tenomodulin up to 21 days of culture. Furthermore, these surfaces enabled the deposition of a tendon-like ECM, supported by the expression of collagens type I and III, tenascin, and decorin. Gene expression analysis revealed a downregulation of osteogenic and fibrosis markers in the presence of TROPO when compared with the control groups, suggesting proper ECM deposition. Remarkably, differentiated cells exposed to TROPO acquired an elastogenic profile due to the evident elastin synthesis and deposition, contributing to the formation of a more mimetic matrix in comparison with the PDA-coated and uncoated conditions. In summary, our biomimetic substrates combining biophysical and biological cues modulate stem cell behavior potentiating their long-term tenogenic commitment and the production of an elastin-rich ECM.
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Affiliation(s)
- Helena Almeida
- 3B's Research Group, I3Bs-Research Institute on Biomaterials, Biodegradables and Biomimetics , University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine , AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra , Barco, 4805-017 Guimarães , Portugal
- ICVS/3B's-PT Government Associate Laboratory , Braga/Guimarães , Portugal
| | - Rui M A Domingues
- 3B's Research Group, I3Bs-Research Institute on Biomaterials, Biodegradables and Biomimetics , University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine , AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra , Barco, 4805-017 Guimarães , Portugal
- ICVS/3B's-PT Government Associate Laboratory , Braga/Guimarães , Portugal
- The Discoveries Centre for Regenerative and Precision Medicine , Headquarters at University of Minho , Avepark , Barco, 4805-017 Guimarães , Portugal
| | | | - Ricardo A Pires
- 3B's Research Group, I3Bs-Research Institute on Biomaterials, Biodegradables and Biomimetics , University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine , AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra , Barco, 4805-017 Guimarães , Portugal
- ICVS/3B's-PT Government Associate Laboratory , Braga/Guimarães , Portugal
- The Discoveries Centre for Regenerative and Precision Medicine , Headquarters at University of Minho , Avepark , Barco, 4805-017 Guimarães , Portugal
| | - Ana I Gonçalves
- 3B's Research Group, I3Bs-Research Institute on Biomaterials, Biodegradables and Biomimetics , University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine , AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra , Barco, 4805-017 Guimarães , Portugal
- ICVS/3B's-PT Government Associate Laboratory , Braga/Guimarães , Portugal
| | - Manuel Gómez-Florit
- 3B's Research Group, I3Bs-Research Institute on Biomaterials, Biodegradables and Biomimetics , University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine , AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra , Barco, 4805-017 Guimarães , Portugal
- ICVS/3B's-PT Government Associate Laboratory , Braga/Guimarães , Portugal
| | - Rui L Reis
- 3B's Research Group, I3Bs-Research Institute on Biomaterials, Biodegradables and Biomimetics , University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine , AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra , Barco, 4805-017 Guimarães , Portugal
- ICVS/3B's-PT Government Associate Laboratory , Braga/Guimarães , Portugal
- The Discoveries Centre for Regenerative and Precision Medicine , Headquarters at University of Minho , Avepark , Barco, 4805-017 Guimarães , Portugal
| | | | - Manuela E Gomes
- 3B's Research Group, I3Bs-Research Institute on Biomaterials, Biodegradables and Biomimetics , University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine , AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra , Barco, 4805-017 Guimarães , Portugal
- ICVS/3B's-PT Government Associate Laboratory , Braga/Guimarães , Portugal
- The Discoveries Centre for Regenerative and Precision Medicine , Headquarters at University of Minho , Avepark , Barco, 4805-017 Guimarães , Portugal
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22
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Lee AH, Elliott DM. Comparative multi-scale hierarchical structure of the tail, plantaris, and Achilles tendons in the rat. J Anat 2019; 234:252-262. [PMID: 30484871 PMCID: PMC6326909 DOI: 10.1111/joa.12913] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2018] [Indexed: 12/19/2022] Open
Abstract
Rodent tendons are widely used to study human pathologies such as tendinopathy and repair, and to address fundamental physiological questions about development, growth, and remodeling. However, how the gross morphology and multi-scale hierarchical structure of rat tendons, such as the tail, plantaris, and Achilles tendons, compare with that of human tendons are unknown. In addition, there remains disagreement about terminology and definitions. Specifically, the definitions of fascicle and fiber are often dependent on diameter sizes, not their characteristic features, and these definitions impair the ability to compare hierarchical structure across species, where the sizes of the fiber and fascicle may change with animal size and tendon function. Thus, the objective of the study was to select a single species that is commonly used for tendon research (rat) and tendons with varying mechanical functions (tail, plantaris, Achilles) to evaluate the hierarchical structure at multiple length scales using histology, SEM, and confocal imaging. With the exception of the specialized rat tail tendon, we confirmed that in rat tendons there are no fascicles and the fiber is the largest subunit. In addition, we provided a structurally based definition of a fiber as a bundle of collagen fibrils that is surrounded by elongated cells, and this definition was supported by both histologically processed and unprocessed samples. In all rat tendons studied, the fiber diameters were consistently between 10 and 50 μm, and this diameter range appears to be conserved across larger species. Specific recommendations were made highlighting the strengths and limitations of each rat tendon as a research model. Understanding the hierarchical structure of tendon can advance the design and interpretation of experiments and development of tissue-engineered constructs.
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Affiliation(s)
- Andrea H. Lee
- Department of Biomedical EngineeringUniversity of DelawareNewarkUSA
| | - Dawn M. Elliott
- Department of Biomedical EngineeringUniversity of DelawareNewarkUSA
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23
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Guzzoni V, Selistre-de-Araújo HS, Marqueti RDC. Tendon Remodeling in Response to Resistance Training, Anabolic Androgenic Steroids and Aging. Cells 2018; 7:E251. [PMID: 30544536 PMCID: PMC6316563 DOI: 10.3390/cells7120251] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 11/30/2018] [Accepted: 11/30/2018] [Indexed: 12/14/2022] Open
Abstract
Exercise training (ET), anabolic androgenic steroids (AAS), and aging are potential factors that affect tendon homeostasis, particularly extracellular matrix (ECM) remodeling. The goal of this review is to aggregate findings regarding the effects of resistance training (RT), AAS, and aging on tendon homeostasis. Data were gathered from our studies regarding the impact of RT, AAS, and aging on the calcaneal tendon (CT) of rats. We demonstrated a series of detrimental effects of AAS and aging on functional and biomechanical parameters, including the volume density of blood vessel cells, adipose tissue cells, tendon calcification, collagen content, the regulation of the major proteins related to the metabolic/development processes of tendons, and ECM remodeling. Conversely, RT seems to mitigate age-related tendon dysfunction. Our results suggest that AAS combined with high-intensity RT exert harmful effects on ECM remodeling, and also instigate molecular and biomechanical adaptations in the CT. Moreover, we provide further information regarding the harmful effects of AAS on tendons at a transcriptional level, and demonstrate the beneficial effects of RT against the age-induced tendon adaptations of rats. Our studies might contribute in terms of clinical approaches in favor of the benefits of ET against tendinopathy conditions, and provide a warning on the harmful effects of the misuse of AAS on tendon development.
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Affiliation(s)
- Vinicius Guzzoni
- Departamento de Biologia Molecular e Celular, Universidade Federal da Paraíba, João Pessoa 58051-970, Paraíba, Brazil.
| | | | - Rita de Cássia Marqueti
- Graduate Program of Rehabilitation Science, University of Brasilia, Distrito Federal, Brasília 70840-901, Distrito Federal, Brazil.
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24
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Zitnay JL, Weiss JA. Load transfer, damage, and failure in ligaments and tendons. J Orthop Res 2018; 36:3093-3104. [PMID: 30175857 PMCID: PMC6454883 DOI: 10.1002/jor.24134] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 08/14/2018] [Indexed: 02/04/2023]
Abstract
The function of ligaments and tendons is to support and transmit loads applied to the musculoskeletal system. These tissues are often able to perform their function for many decades; however, connective tissue disease and injury can compromise ligament and tendon integrity. A range of protein and non-protein constituents, combined in a complex structural hierarchy from the collagen molecule to the tissue and covering nanometer to centimeter length scales, govern tissue function, and impart characteristic non-linear material behavior. This review summarizes the structure of ligaments and tendons, the roles of their constituent components for load transfer across the hierarchy of structure, and the current understanding of how damage occurs in these tissues. Disease and injury can alter the constituent make-up and structural organization of ligaments and tendons, affecting tissue function, while also providing insight to the role and interactions of individual constituents. The studies and techniques presented here have helped to understand the relationship between tissue constituents and the physical mechanisms (e.g., stretching, sliding) that govern material behavior at and between length scales. In recent years, new techniques have been developed to probe ever smaller length scales and may help to elucidate mechanisms of load transfer and damage and the molecular constituents involved in the in the earliest stages of ligament and tendon damage. A detailed understanding of load transfer and damage from the molecular to the tissue level may elucidate targets for the treatment of connective tissue diseases and inform practice to prevent and rehabilitate ligament and tendon injuries. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:3093-3104, 2018.
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Affiliation(s)
- Jared L. Zitnay
- Department of Bioengineering, and Scientific Computing and Imaging Institute University of Utah
| | - Jeffrey A. Weiss
- Department of Bioengineering, and Scientific Computing and Imaging Institute University of Utah,Department of Orthopaedics, University of Utah
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25
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Shu CC, Smith MM, Appleyard RC, Little CB, Melrose J. Achilles and tail tendons of perlecan exon 3 null heparan sulphate deficient mice display surprising improvement in tendon tensile properties and altered collagen fibril organisation compared to C57BL/6 wild type mice. PeerJ 2018; 6:e5120. [PMID: 30042881 PMCID: PMC6056265 DOI: 10.7717/peerj.5120] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 06/07/2018] [Indexed: 02/02/2023] Open
Abstract
The aim of this study was to determine the role of the perlecan (Hspg2) heparan sulphate (HS) side chains on cell and matrix homeostasis in tail and Achilles tendons in 3 and 12 week old Hspg2 exon 3 null HS deficient (Hspg2Δ3 − ∕Δ3 −) and C57 BL/6 Wild Type (WT) mice. Perlecan has important cell regulatory and matrix organizational properties through HS mediated interactions with a range of growth factors and morphogens and with structural extracellular matrix glycoproteins which define tissue function and allow the resident cells to regulate tissue homeostasis. It was expected that ablation of the HS chains on perlecan would severely disrupt normal tendon organization and functional properties and it was envisaged that this study would better define the role of HS in normal tendon function and in tendon repair processes. Tail and Achilles tendons from each genotype were biomechanically tested (ultimate tensile stress (UTS), tensile modulus (TM)) and glycosaminoglycan (GAG) and collagen (hydroxyproline) compositional analyses were undertaken. Tenocytes were isolated from tail tendons from each mouse genotype and grown in monolayer culture. These cultures were undertaken in the presence of FGF-2 to assess the cell signaling properties of each genotype. Total RNA was isolated from 3–12 week old tail and Achilles tendons and qRT-PCR was undertaken to assess the expression of the following genes Vcan, Bgn, Dcn, Lum, Hspg2, Ltbp1, Ltbp2, Eln and Fbn1. Type VI collagen and perlecan were immunolocalised in tail tendon and collagen fibrils were imaged using transmission electron microscopy (TEM). FGF-2 stimulated tenocyte monolayers displayed elevated Adamts4, Mmp2, 3, 13 mRNA levels compared to WT mice. Non-stimulated tendon Col1A1, Vcan, Bgn, Dcn, Lum, Hspg2, Ltbp1, Ltbp2, Eln and Fbn1 mRNA levels showed no major differences between the two genotypes other than a decline with ageing while LTBP2 expression increased. Eln expression also declined to a greater extent in the perlecan exon 3 null mice (P < 0.05). Type VI collagen and perlecan were immunolocalised in tail tendon and collagen fibrils imaged using transmission electron microscopy (TEM). This indicated a more compact form of collagen localization in the perlecan exon 3 null mice. Collagen fibrils were also smaller by TEM, which may facilitate a more condensed fibril packing accounting for the superior UTS displayed by the perlecan exon 3 null mice. The amplified catabolic phenotype of Hspg2Δ3 − ∕Δ3 − mice may account for the age-dependent decline in GAG observed in tail tendon over 3 to 12 weeks. After Achilles tenotomy Hspg2Δ3 − ∕Δ3 − and WT mice had similar rates of recovery of UTS and TM over 12 weeks post operatively indicating that a deficiency of HS was not detrimental to tendon repair.
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Affiliation(s)
- Cindy C Shu
- Raymond Purves Bone and Joint Laboratory, Kolling Institute of Medical Research, University of Sydney, Australia
| | - Margaret M Smith
- Raymond Purves Bone and Joint Laboratory, Kolling Institute of Medical Research, University of Sydney, Australia
| | - Richard C Appleyard
- Murray Maxwell Biomechanics Laboratory, Royal North Shore Hospital, University of Sydney, St. Leonards, New South Wales, Australia.,Surgical Skills Laboratory, Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales, Australia
| | - Christopher B Little
- Raymond Purves Bone and Joint Laboratory, Kolling Institute of Medical Research, University of Sydney, Australia.,Sydney Medical School, Northern, University of Sydney, Sydney, Australia
| | - James Melrose
- Raymond Purves Bone and Joint Laboratory, Kolling Institute of Medical Research, University of Sydney, Australia.,Sydney Medical School, Northern, University of Sydney, Sydney, Australia.,Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
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26
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Eekhoff JD, Fang F, Kahan LG, Espinosa G, Cocciolone AJ, Wagenseil JE, Mecham RP, Lake SP. Functionally Distinct Tendons From Elastin Haploinsufficient Mice Exhibit Mild Stiffening and Tendon-Specific Structural Alteration. J Biomech Eng 2018; 139:2654667. [PMID: 28916838 DOI: 10.1115/1.4037932] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Indexed: 12/23/2022]
Abstract
Elastic fibers are present in low quantities in tendon, where they are located both within fascicles near tenocytes and more broadly in the interfascicular matrix (IFM). While elastic fibers have long been known to be significant in the mechanics of elastin-rich tissue (i.e., vasculature, skin, lungs), recent studies have suggested a mechanical role for elastic fibers in tendons that is dependent on specific tendon function. However, the exact contribution of elastin to properties of different types of tendons (e.g., positional, energy-storing) remains unknown. Therefore, this study purposed to evaluate the role of elastin in the mechanical properties and collagen alignment of functionally distinct supraspinatus tendons (SSTs) and Achilles tendons (ATs) from elastin haploinsufficient (HET) and wild type (WT) mice. Despite the significant decrease in elastin in HET tendons, a slight increase in linear stiffness of both tendons was the only significant mechanical effect of elastin haploinsufficiency. Additionally, there were significant changes in collagen nanostructure and subtle alteration to collagen alignment in the AT but not the SST. Hence, elastin may play only a minor role in tendon mechanical properties. Alternatively, larger changes to tendon mechanics may have been mitigated by developmental compensation of HET tendons and/or the role of elastic fibers may be less prominent in smaller mouse tendons compared to the larger bovine and human tendons evaluated in previous studies. Further research will be necessary to fully elucidate the influence of various elastic fiber components on structure-function relationships in functionally distinct tendons.
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Affiliation(s)
- Jeremy D Eekhoff
- Department of Biomedical Engineering, Washington University in St. Louis One Brookings Drive, St. Louis, MO 63130
| | - Fei Fang
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130
| | - Lindsey G Kahan
- Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130
| | - Gabriela Espinosa
- Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130
| | - Austin J Cocciolone
- Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130
| | - Jessica E Wagenseil
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130
| | - Robert P Mecham
- Department of Cell Biology and Physiology, Washington University in St. Louis, 660 South Euclid Avenue, St. Louis, MO 63110
| | - Spencer P Lake
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130.,Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130.,Department of Orthopaedic Surgery, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130 e-mail:
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27
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Connizzo BK, Grodzinsky AJ. Multiscale Poroviscoelastic Compressive Properties of Mouse Supraspinatus Tendons Are Altered in Young and Aged Mice. J Biomech Eng 2018; 140:2666618. [PMID: 29238818 PMCID: PMC5816244 DOI: 10.1115/1.4038745] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 12/04/2017] [Indexed: 02/02/2023]
Abstract
Rotator cuff disorders are one of the most common causes of shoulder pain and disability in the aging population but, unfortunately, the etiology is still unknown. One factor thought to contribute to the progression of disease is the external compression of the rotator cuff tendons, which can be significantly increased by age-related changes such as muscle weakness and poor posture. The objective of this study was to investigate the baseline compressive response of tendon and determine how this response is altered during maturation and aging. We did this by characterizing the compressive mechanical, viscoelastic, and poroelastic properties of young, mature, and aged mouse supraspinatus tendons using macroscale indentation testing and nanoscale high-frequency AFM-based rheology testing. Using these multiscale techniques, we found that aged tendons were stiffer than their mature counterparts and that both young and aged tendons exhibited increased hydraulic permeability and energy dissipation. We hypothesize that regional and age-related variations in collagen morphology and organization are likely responsible for changes in the multiscale compressive response as these structural parameters may affect fluid flow. Importantly, these results suggest a role for age-related changes in the progression of tendon degeneration, and we hypothesize that decreased ability to resist compressive loading via fluid pressurization may result in damage to the extracellular matrix (ECM) and ultimately tendon degeneration. These studies provide insight into the regional multiscale compressive response of tendons and indicate that altered compressive properties in aging tendons may be a major contributor to overall tendon degeneration.
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Affiliation(s)
- Brianne K. Connizzo
- Department of Biological Engineering,
Massachusetts Institute of Technology,
Cambridge, MA 02139
| | - Alan J. Grodzinsky
- Department of Biological Engineering,Massachusetts Institute of Technology,
Cambridge, MA 02139;
Center for Biomedical Engineering,Massachusetts Institute of Technology,
Cambridge, MA 02139;
Department of Electrical Engineeringand Computer Science,
Massachusetts Institute of Technology,
Cambridge, MA 02139;
Department of Mechanical Engineering,Massachusetts Institute of Technology,
Cambridge, MA 02139
e-mail:
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28
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Szczesny SE, Fetchko KL, Dodge GR, Elliott DM. Evidence that interfibrillar load transfer in tendon is supported by small diameter fibrils and not extrafibrillar tissue components. J Orthop Res 2017; 35:2127-2134. [PMID: 28071819 PMCID: PMC5503823 DOI: 10.1002/jor.23517] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 01/06/2017] [Indexed: 02/06/2023]
Abstract
Collagen fibrils in tendon are believed to be discontinuous and transfer tensile loads through shear forces generated during interfibrillar sliding. However, the structures that transmit these interfibrillar forces are unknown. Various extrafibrillar tissue components (e.g., glycosaminoglycans, collagens XII and XIV) have been suggested to transmit interfibrillar loads by bridging collagen fibrils. Alternatively, collagen fibrils may interact directly through physical fusions and interfibrillar branching. The objective of this study was to test whether extrafibrillar proteins are necessary to transmit load between collagen fibrils or if interfibrillar load transfer is accomplished directly by the fibrils themselves. Trypsin digestions were used to remove a broad spectrum of extrafibrillar proteins and measure their contribution to the multiscale mechanics of rat tail tendon fascicles. Additionally, images obtained from serial block-face scanning electron microscopy were used to determine the three-dimensional fibrillar organization in tendon fascicles and identify any potential interfibrillar interactions. While trypsin successfully removed several extrafibrillar tissue components, there was no change in the macroscale fascicle mechanics or fibril:tissue strain ratio. Furthermore, the imaging data suggested that a network of smaller diameter fibrils (<150 nm) wind around and fuse with their neighboring larger diameter fibrils. These findings demonstrate that interfibrillar load transfer is not supported by extrafibrillar tissue components and support the hypothesis that collagen fibrils are capable of transmitting loads themselves. Conclusively determining how fibrils bear load within tendon is critical for identifying the mechanisms that impair tissue function with degeneration and for restoring tissue properties via cell-mediated regeneration or engineered tissue replacements. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2127-2134, 2017.
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Affiliation(s)
- Spencer E. Szczesny
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 South 33rd St, Philadelphia, PA 19104
| | - Kristen L. Fetchko
- Department of Biomedical Engineering, University of Delaware, 161 Colburn Lab, 150 Academy Street, Newark, DE 19716
| | - George R. Dodge
- Department of Orthopaedic Surgery, University of Pennsylvania, 424 Stemmler Hall, 36 St & Hamilton Walk, Philadelphia, PA 19104,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Veterans Affairs Medical Center, 3900 Woodland Ave, Philadelphia, PA 19104
| | - Dawn M. Elliott
- Department of Biomedical Engineering, University of Delaware, 161 Colburn Lab, 150 Academy Street, Newark, DE 19716,Corresponding Author: Dawn M. Elliott, Ph.D., 161 Colburn Lab, 150 Academy Street, Newark, DE 19716, Phone: 302-831-1295,
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29
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Patel D, Sharma S, Bryant SJ, Screen HRC. Recapitulating the Micromechanical Behavior of Tension and Shear in a Biomimetic Hydrogel for Controlling Tenocyte Response. Adv Healthc Mater 2017; 6. [PMID: 28026126 PMCID: PMC5469035 DOI: 10.1002/adhm.201601095] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 11/21/2016] [Indexed: 12/11/2022]
Abstract
A fiber composite system is presented which recapitulates the fiber-composite-like nature of tissues and generates similar modes of shear and tension. The shear/tension ratio can be customized during composite manufacture and incorporates viable cells. The system is a valuable tool for mechanotransduction research, providing a platform with physiologically relevant conditions for investigating cell behavior in different tissue types.
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Affiliation(s)
- Dharmesh Patel
- School of Engineering and Materials Science; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Sadhana Sharma
- Department of Chemical and Biological Engineering; University of Colorado Boulder; Boulder CO 80303 USA
| | - Stephanie J. Bryant
- Department of Chemical and Biological Engineering; Material Science and Engineering Program; BioFrontiers Institute; University of Colorado; Boulder CO 80303 USA
| | - Hazel R. C. Screen
- School of Engineering and Materials Science; Queen Mary University of London; Mile End Road London E1 4NS UK
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30
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Connizzo BK, Grodzinsky AJ. Tendon exhibits complex poroelastic behavior at the nanoscale as revealed by high-frequency AFM-based rheology. J Biomech 2017; 54:11-18. [PMID: 28233551 DOI: 10.1016/j.jbiomech.2017.01.029] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 12/26/2016] [Accepted: 01/17/2017] [Indexed: 12/14/2022]
Abstract
Tendons transmit load from muscle to bone by utilizing their unique static and viscoelastic tensile properties. These properties are highly dependent on the composition and structure of the tissue matrix, including the collagen I hierarchy, proteoglycans, and water. While the role of matrix constituents in the tensile response has been studied, their role in compression, particularly in matrix pressurization via regulation of fluid flow, is not well understood. Injured or diseased tendons and tendon regions that naturally experience compression are known to have alterations in glycosaminoglycan content, which could modulate fluid flow and ultimately mechanical function. While recent theoretical studies have predicted tendon mechanics using poroelastic theory, no experimental data have directly demonstrated such behavior. In this study, we use high-bandwidth AFM-based rheology to determine the dynamic response of tendons to compressive loading at the nanoscale and to determine the presence of poroelastic behavior. Tendons are found to have significant characteristic dynamic relaxation behavior occurring at both low and high frequencies. Classic poroelastic behavior is observed, although we hypothesize that the full dynamic response is caused by a combination of flow-dependent poroelasticity as well as flow-independent viscoelasticity. Tendons also demonstrate regional dependence in their dynamic response, particularly near the junction of tendon and bone, suggesting that the structural and compositional heterogeneity in tendon may be responsible for regional poroelastic behavior. Overall, these experiments provide the foundation for understanding fluid-flow-dependent poroelastic mechanics of tendon, and the methodology is valuable for assessing changes in tendon matrix compressive behavior at the nanoscale.
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Affiliation(s)
- Brianne K Connizzo
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Alan J Grodzinsky
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Center for Biomedical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States.
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