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Davis ZG, Koch DW, Watson SL, Scull GM, Brown AC, Schnabel LV, Fisher MB. Controlled Stiffness of Direct-Write, Near-Field Electrospun Gelatin Fibers Generates Differences in Tenocyte Morphology and Gene Expression. J Biomech Eng 2024; 146:091008. [PMID: 38529730 PMCID: PMC11080953 DOI: 10.1115/1.4065163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/18/2024] [Accepted: 03/18/2024] [Indexed: 03/27/2024]
Abstract
Tendinopathy is a leading cause of mobility issues. Currently, the cell-matrix interactions involved in the development of tendinopathy are not fully understood. In vitro tendon models provide a unique tool for addressing this knowledge gap as they permit fine control over biochemical, micromechanical, and structural aspects of the local environment to explore cell-matrix interactions. In this study, direct-write, near-field electrospinning of gelatin solution was implemented to fabricate micron-scale fibrous scaffolds that mimic native collagen fiber size and orientation. The stiffness of these fibrous scaffolds was found to be controllable between 1 MPa and 8 MPa using different crosslinking methods (EDC, DHT, DHT+EDC) or through altering the duration of crosslinking with EDC (1 h to 24 h). EDC crosslinking provided the greatest fiber stability, surviving up to 3 weeks in vitro. Differences in stiffness resulted in phenotypic changes for equine tenocytes with low stiffness fibers (∼1 MPa) promoting an elongated nuclear aspect ratio while those on high stiffness fibers (∼8 MPa) were rounded. High stiffness fibers resulted in the upregulation of matrix metalloproteinase (MMPs) and proteoglycans (possible indicators for tendinopathy) relative to low stiffness fibers. These results demonstrate the feasibility of direct-written gelatin scaffolds as tendon in vitro models and provide evidence that matrix mechanical properties may be crucial factors in cell-matrix interactions during tendinopathy formation.
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Affiliation(s)
- Zachary G. Davis
- Joint Department of Biomedical Engineering, North Carolina State University, University of North Carolina at Chapel Hill, Raleigh, NC 27695; Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27695
| | - Drew W. Koch
- College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27695; Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27695
- North Carolina State University
| | - Samantha L. Watson
- Joint Department of Biomedical Engineering, North Carolina State University, University of North Carolina at Chapel Hill, Raleigh, NC 27695
| | - Grant M. Scull
- Joint Department of Biomedical Engineering, North Carolina State University, University of North Carolina at Chapel Hill, Raleigh, NC 27695; Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27695
| | - Ashley C. Brown
- Joint Department of Biomedical Engineering, North Carolina State University, University of North Carolina at Chapel Hill, Raleigh, NC 27695; Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27695
| | - Lauren V. Schnabel
- College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27695; Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27695
- North Carolina State University
| | - Matthew B. Fisher
- Joint Department of Biomedical Engineering, North Carolina State University, University of North Carolina at Chapel Hill, Raleigh, NC 27695; Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27695; Department of Orthopaedics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
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2
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Troop LD, Puetzer JL. Intermittent cyclic stretch of engineered ligaments drives hierarchical collagen fiber maturation in a dose- and organizational-dependent manner. Acta Biomater 2024:S1742-7061(24)00397-0. [PMID: 39025395 DOI: 10.1016/j.actbio.2024.07.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 07/10/2024] [Accepted: 07/11/2024] [Indexed: 07/20/2024]
Abstract
Hierarchical collagen fibers are the primary source of strength in tendons and ligaments; however, these fibers largely do not regenerate after injury or with repair, resulting in limited treatment options. We previously developed a static culture system that guides ACL fibroblasts to produce native-sized fibers and early fascicles by 6 weeks. These constructs are promising ligament replacements, but further maturation is needed. Mechanical cues are critical for development in vivo and in engineered tissues; however, the effect on larger fiber and fascicle formation is largely unknown. Our objective was to investigate whether intermittent cyclic stretch, mimicking rapid muscle activity, drives further maturation in our system to create stronger engineered replacements and to explore whether cyclic loading has differential effects on cells at different degrees of collagen organization to better inform engineered tissue maturation protocols. Constructs were loaded with an established intermittent cyclic loading regime at 5 or 10 % strain for up to 6 weeks and compared to static controls. Cyclic loading drove cells to increase hierarchical collagen organization, collagen crimp, and tissue tensile properties, ultimately producing constructs that matched or exceeded immature ACL properties. Further, the effect of loading on cells varied depending on degree of organization. Specifically, 10 % load drove early improvements in tensile properties and composition, while 5 % load was more beneficial later in culture, suggesting a shift in mechanotransduction. This study provides new insight into how cyclic loading affects cell-driven hierarchical fiber formation and maturation, which will help to develop better rehabilitation protocols and engineer stronger replacements. STATEMENT OF SIGNIFICANCE: Collagen fibers are the primary source of strength and function in tendons and ligaments throughout the body. These fibers have limited regenerate after injury, with repair, and in engineered replacements, reducing treatment options. Cyclic load has been shown to improve fibril level alignment, but its effect at the larger fiber and fascicle length-scale is largely unknown. Here, we demonstrate intermittent cyclic loading increases cell-driven hierarchical fiber formation and tissue mechanics, producing engineered replacements with similar organization and mechanics as immature ACLs. This study provides new insight into how cyclic loading affects cell-driven fiber maturation. A better understanding of how mechanical cues regulate fiber formation will help to develop better engineered replacements and rehabilitation protocols to drive repair after injury.
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Affiliation(s)
- Leia D Troop
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA 23284, United States
| | - Jennifer L Puetzer
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA 23284, United States; Department of Orthopaedic Surgery, Virginia Commonwealth University, Richmond, VA 23284, United States.
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3
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Aggouras AN, Stowe EJ, Mlawer SJ, Connizzo BK. Aged Tendons Exhibit Altered Mechanisms of Strain-Dependent Extracellular Matrix Remodeling. J Biomech Eng 2024; 146:071009. [PMID: 38584416 PMCID: PMC11080950 DOI: 10.1115/1.4065270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 04/02/2024] [Accepted: 04/03/2024] [Indexed: 04/09/2024]
Abstract
Aging is a primary risk factor for degenerative tendon injuries, yet the etiology and progression of this degeneration are poorly understood. While aged tendons have innate cellular differences that support a reduced ability to maintain mechanical tissue homeostasis, the response of aged tendons to altered levels of mechanical loading has not yet been studied. To address this question, we subjected young and aged murine flexor tendon explants to various levels of in vitro tensile strain. We first compared the effect of static and cyclic strain on matrix remodeling in young tendons, finding that cyclic strain is optimal for studying remodeling in vitro. We then investigated the remodeling response of young and aged tendon explants after 7 days of varied mechanical stimulus (stress deprivation, 1%, 3%, 5%, or 7% cyclic strain) via assessment of tissue composition, biosynthetic capacity, and degradation profiles. We hypothesized that aged tendons would show muted adaptive responses to changes in tensile strain and exhibit a shifted mechanical setpoint, at which the remodeling balance is optimal. Interestingly, we found that 1% cyclic strain best maintains native physiology while promoting extracellular matrix (ECM) turnover for both age groups. However, aged tendons display fewer strain-dependent changes, suggesting a reduced ability to adapt to altered levels of mechanical loading. This work has a significant impact on understanding the regulation of tissue homeostasis in aged tendons, which can inform clinical rehabilitation strategies for treating elderly patients.
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Affiliation(s)
- Anthony N. Aggouras
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02115
- Boston University
| | - Emma J. Stowe
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02115
| | - Samuel J. Mlawer
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02115
- Boston University
| | - Brianne K. Connizzo
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02115
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4
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Mlawer SJ, Frank EH, Connizzo BK. Aged tendons lack adaptive response to acute compressive injury. J Orthop Res 2024; 42:973-984. [PMID: 38041209 PMCID: PMC11009076 DOI: 10.1002/jor.25752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/24/2023] [Accepted: 11/29/2023] [Indexed: 12/03/2023]
Abstract
Rotator cuff tendinopathy has a multifactorial etiology, with both aging and external compression found to influence disease progression. However, tendon's response to these factors is still poorly understood and in vivo animal models make it difficult to decouple these effects. Therefore, we developed an explant culture model that allows us to directly apply compression to tendons and then observe their biological responses. Using this model, we applied a single acute compressive injury to C57BL/6J flexor digitorum longus tendon explants and observed changes in viability, metabolic activity, matrix composition, matrix biosynthesis, matrix structure, gene expression, and mechanical properties. We hypothesized that a single acute compressive load would result in an injury response in tendon and that this effect would be amplified in aged tendons. We found that young tendons had increased matrix turnover with a decrease in small leucine-rich proteoglycans, increase in compression-resistant proteoglycan aggrecan, increase in collagen synthesis, and an upregulation of collagen-degrading MMP-9. Aged tendons lacked any of these adaptive responses and instead had decreased metabolic activity and collagen synthesis. This implies that aged tendons lack the adaptation mechanisms required to return to homeostasis, and therefore are at greater risk for compression-induced injury. Overall, we present a novel compressive injury model that demonstrates lasting age-dependent changes and has the potential to examine the long-term response of tendon to a variety of compressive loading conditions.
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Affiliation(s)
- Samuel J. Mlawer
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, United States
| | - Eliot H. Frank
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Brianne K. Connizzo
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, United States
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5
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Dvorak N, Liu Z, Mouthuy PA. Soft bioreactor systems: a necessary step toward engineered MSK soft tissue? Front Robot AI 2024; 11:1287446. [PMID: 38711813 PMCID: PMC11070535 DOI: 10.3389/frobt.2024.1287446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 03/12/2024] [Indexed: 05/08/2024] Open
Abstract
A key objective of tissue engineering (TE) is to produce in vitro funcional grafts that can replace damaged tissues or organs in patients. TE uses bioreactors, which are controlled environments, allowing the application of physical and biochemical cues to relevant cells growing in biomaterials. For soft musculoskeletal (MSK) tissues such as tendons, ligaments and cartilage, it is now well established that applied mechanical stresses can be incorporated into those bioreactor systems to support tissue growth and maturation via activation of mechanotransduction pathways. However, mechanical stresses applied in the laboratory are often oversimplified compared to those found physiologically and may be a factor in the slow progression of engineered MSK grafts towards the clinic. In recent years, an increasing number of studies have focused on the application of complex loading conditions, applying stresses of different types and direction on tissue constructs, in order to better mimic the cellular environment experienced in vivo. Such studies have highlighted the need to improve upon traditional rigid bioreactors, which are often limited to uniaxial loading, to apply physiologically relevant multiaxial stresses and elucidate their influence on tissue maturation. To address this need, soft bioreactors have emerged. They employ one or more soft components, such as flexible soft chambers that can twist and bend with actuation, soft compliant actuators that can bend with the construct, and soft sensors which record measurements in situ. This review examines types of traditional rigid bioreactors and their shortcomings, and highlights recent advances of soft bioreactors in MSK TE. Challenges and future applications of such systems are discussed, drawing attention to the exciting prospect of these platforms and their ability to aid development of functional soft tissue engineered grafts.
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Affiliation(s)
| | | | - Pierre-Alexis Mouthuy
- Botnar Institute of Musculoskeletal Sciences, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom
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6
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Troop LD, Puetzer JL. Intermittent Cyclic Stretch of Engineered Ligaments Drives Hierarchical Collagen Fiber Maturation in a Dose- and Organizational-Dependent Manner. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.06.588420. [PMID: 38645097 PMCID: PMC11030411 DOI: 10.1101/2024.04.06.588420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Hierarchical collagen fibers are the primary source of strength in tendons and ligaments, however these fibers do not regenerate after injury or with repair, resulting in limited treatment options. We previously developed a culture system that guides ACL fibroblasts to produce native-sized fibers and fascicles by 6 weeks. These constructs are promising ligament replacements, but further maturation is needed. Mechanical cues are critical for development in vivo and in engineered tissues; however, the effect on larger fiber and fascicle formation is largely unknown. Our objective was to investigate whether intermittent cyclic stretch, mimicking rapid muscle activity, drives further maturation in our system to create stronger engineered replacements and to explore whether cyclic loading has differential effects on cells at different degrees of collagen organization to better inform engineered tissue maturation protocols. Constructs were loaded with an established intermittent cyclic loading regime at 5 or 10% strain for up to 6 weeks and compared to static controls. Cyclic loading drove cells to increase hierarchical collagen organization, collagen crimp, and tissue mechanics, ultimately producing constructs that matched or exceeded immature ACL properties. Further, the effect of loading on cells varied depending on degree of organization. Specifically, 10% load drove early improvements in mechanics and composition, while 5% load was more beneficial later in culture, suggesting a cellular threshold response and a shift in mechanotransduction. This study provides new insight into how cyclic loading affects cell-driven hierarchical fiber formation and maturation, which will help to develop better rehabilitation protocols and engineer stronger replacements.
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Affiliation(s)
- Leia D. Troop
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA, 23284, United States
| | - Jennifer L. Puetzer
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA, 23284, United States
- Department of Orthopaedic Surgery, Virginia Commonwealth University, Richmond, VA, 23284, United States
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7
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Aggouras AN, Stowe EJ, Mlawer SJ, Connizzo BK. Aged Tendons Exhibit Altered Mechanisms of Strain-Dependent Extracellular Matrix Remodeling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.26.577397. [PMID: 38352312 PMCID: PMC10862756 DOI: 10.1101/2024.01.26.577397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/19/2024]
Abstract
Aging is a primary risk factor for degenerative tendon injuries, yet the etiology and progression of this degeneration is poorly understood. While aged tendons have innate cellular differences that support a reduced ability to maintain mechanical tissue homeostasis, the response of aged tendons to altered levels of mechanical loading has not yet been studied. To address this question, we subjected young and aged murine flexor tendon explants to various levels of in vitro tensile strain. We first compared the effect of static and cyclic strain on matrix remodeling in young tendons, finding that cyclic strain is optimal for studying remodeling in vitro. We then investigated the remodeling response of young and aged tendon explants after 7 days of varied mechanical stimulus (stress-deprivation, 1%, 3%, 5%, or 7% cyclic strain) via assessment of tissue composition, biosynthetic capacity, and degradation profiles. We hypothesized that aged tendons would show muted adaptive responses to changes in tensile strain and exhibit a shifted mechanical setpoint, at which the remodeling balance is optimal. Interestingly, we found 1% cyclic strain best maintains native physiology while promoting ECM turnover for both age groups. However, aged tendons display fewer strain-dependent changes, suggesting a reduced ability to adapt to altered levels of mechanical loading. This work has significant impact in understanding the regulation of tissue homeostasis in aged tendons, which can inform clinical rehabilitation strategies for treating elderly patients.
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Affiliation(s)
- Anthony N. Aggouras
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA., 44 Cummington Mall, Boston, Massachusetts, USA, 02115
| | - Emma J. Stowe
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA., 44 Cummington Mall, Boston, Massachusetts, USA, 02115
| | - Samuel J. Mlawer
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA., 44 Cummington Mall, Boston, Massachusetts, USA, 02115
| | - Brianne K. Connizzo
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA., 44 Cummington Mall, Boston, Massachusetts, USA, 02115
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8
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Brown ME, Puetzer JL. Enthesis maturation in engineered ligaments is differentially driven by loads that mimic slow growth elongation and rapid cyclic muscle movement. Acta Biomater 2023; 172:106-122. [PMID: 37839633 DOI: 10.1016/j.actbio.2023.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 09/17/2023] [Accepted: 10/10/2023] [Indexed: 10/17/2023]
Abstract
Entheses are complex attachments that translate load between elastic-ligaments and stiff-bone via organizational and compositional gradients. Neither natural healing, repair, nor engineered replacements restore these gradients, contributing to high re-tear rates. Previously, we developed a culture system which guides ligament fibroblasts in high-density collagen gels to develop early postnatal-like entheses, however further maturation is needed. Mechanical cues, including slow growth elongation and cyclic muscle activity, are critical to enthesis development in vivo but these cues have not been widely explored in engineered entheses and their individual contribution to maturation is largely unknown. Our objective here was to investigate how slow stretch, mimicking ACL growth rates, and intermittent cyclic loading, mimicking muscle activity, individually drive enthesis maturation in our system so to shed light on the cues governing enthesis development, while further developing our tissue engineered replacements. Interestingly, we found these loads differentially drive organizational maturation, with slow stretch driving improvements in the interface/enthesis region, and cyclic load improving the ligament region. However, despite differentially affecting organization, both loads produced improvements to interface mechanics and zonal composition. This study provides insight into how mechanical cues differentially affect enthesis development, while producing some of the most organized engineered enthesis to date. STATEMENT OF SIGNIFICANCE: Entheses attach ligaments to bone and are critical to load transfer; however, entheses do not regenerate with repair or replacement, contributing to high re-tear rates. Mechanical cues are critical to enthesis development in vivo but their individual contribution to maturation is largely unknown and they have not been widely explored in engineered replacements. Here, using a novel culture system, we provide new insight into how slow stretch, mimicking ACL growth rates, and intermittent cyclic loading, mimicking muscle activity, differentially affect enthesis maturation in engineered ligament-to-bone tissues, ultimately producing some of the most organized entheses to date. This system is a promising platform to explore cues regulating enthesis formation so to produce functional engineered replacements and better drive regeneration following repair.
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Affiliation(s)
- M Ethan Brown
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA, 23284, United States
| | - Jennifer L Puetzer
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA, 23284, United States; Department of Orthopaedic Surgery, Virginia Commonwealth University, Richmond, VA, 23284, United States.
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9
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Carr BP, Chen Z, Chung JHY, Wallace GG. Collagen Alignment via Electro-Compaction for Biofabrication Applications: A Review. Polymers (Basel) 2022; 14:4270. [PMID: 36297848 PMCID: PMC9609630 DOI: 10.3390/polym14204270] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/05/2022] [Accepted: 10/05/2022] [Indexed: 11/24/2022] Open
Abstract
As the most prevalent structural protein in the extracellular matrix, collagen has been extensively investigated for biofabrication-based applications. However, its utilisation has been impeded due to a lack of sufficient mechanical toughness and the inability of the scaffold to mimic complex natural tissues. The anisotropic alignment of collagen fibres has been proven to be an effective method to enhance its overall mechanical properties and produce biomimetic scaffolds. This review introduces the complicated scenario of collagen structure, fibril arrangement, type, function, and in addition, distribution within the body for the enhancement of collagen-based scaffolds. We describe and compare existing approaches for the alignment of collagen with a sharper focus on electro-compaction. Additionally, various effective processes to further enhance electro-compacted collagen, such as crosslinking, the addition of filler materials, and post-alignment fabrication techniques, are discussed. Finally, current challenges and future directions for the electro-compaction of collagen are presented, providing guidance for the further development of collagenous scaffolds for bioengineering and nanotechnology.
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Affiliation(s)
| | | | - Johnson H. Y. Chung
- Australian Research Council Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Gordon G. Wallace
- Australian Research Council Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
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10
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Sander IL, Dvorak N, Stebbins JA, Carr AJ, Mouthuy PA. Advanced Robotics to Address the Translational Gap in Tendon Engineering. CYBORG AND BIONIC SYSTEMS 2022; 2022:9842169. [PMID: 36285305 PMCID: PMC9508494 DOI: 10.34133/2022/9842169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/25/2022] [Indexed: 12/02/2022] Open
Abstract
Tendon disease is a significant and growing burden to healthcare systems. One strategy to address this challenge is tissue engineering. A widely held view in this field is that mechanical stimulation provided to constructs should replicate the mechanical environment of native tissue as closely as possible. We review recent tendon tissue engineering studies in this article and highlight limitations of conventional uniaxial tensile bioreactors used in current literature. Advanced robotic platforms such as musculoskeletal humanoid robots and soft robotic actuators are promising technologies which may help address translational gaps in tendon tissue engineering. We suggest the proposed benefits of these technologies and identify recent studies which have worked to implement these technologies in tissue engineering. Lastly, key challenges to address in adapting these robotic technologies and proposed future research directions for tendon tissue engineering are discussed.
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Affiliation(s)
- Iain L. Sander
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford OX3 7LD, UK
- Oxford Gait Laboratory, Nuffield Orthopaedic Centre, Tebbit Centre, Windmill Road, Oxford OX3 7HE, UK
| | - Nicole Dvorak
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford OX3 7LD, UK
| | - Julie A. Stebbins
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford OX3 7LD, UK
- Oxford Gait Laboratory, Nuffield Orthopaedic Centre, Tebbit Centre, Windmill Road, Oxford OX3 7HE, UK
| | - Andrew J. Carr
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford OX3 7LD, UK
| | - Pierre-Alexis Mouthuy
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford OX3 7LD, UK
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11
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Saito T, Nakamichi R, Yoshida A, Hiranaka T, Okazaki Y, Nezu S, Matsuhashi M, Shimamura Y, Furumatsu T, Nishida K, Ozaki T. The effect of mechanical stress on enthesis homeostasis in a rat Achilles enthesis organ culture model. J Orthop Res 2022; 40:1872-1882. [PMID: 34783068 DOI: 10.1002/jor.25210] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 10/19/2021] [Accepted: 10/30/2021] [Indexed: 02/04/2023]
Abstract
Tendons and ligaments are jointed to bones via an enthesis that is essential to the proper function of the muscular and skeletal structures. The aim of the study is to investigate the effect of mechanical stress on the enthesis. We used ex vivo models in organ cultures of rat Achilles tendons with calcaneus including the enthesis. The organ was attached to a mechanical stretching apparatus that can conduct cyclic tensile strain. We made the models of 1-mm elongation (0.5 Hz, 3% elongation), 2-mm elongation (0.5 Hz, 5% elongation), and no stress. Histological evaluation by Safranin O staining and Toluidin Blue and Picro Sirius red staining was conducted. Expression of sex-determining region Y-box 9 (Sox9), scleraxis (Scx), Runt-related transcription factor 2 (Runx2), and matrix metalloproteinase 13 (Mmp13) were examined by real-time polymerase chain reaction and immunocytochemistry. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end-labeling and live/dead staining and was conducted for evaluation of the apoptosis and cell viability. The structure of the enthesis was most maintained in the model of 1-mm elongation. The electronic microscope showed that the enthesis of the no stress model had ill-defined borders between fibrocartilage and mineralized fibrocartilage, and that calcification of mineralized fibrocartilage occurred in the model of 2-mm elongation. Sox9 and Scx was upregulated by 1-mm elongation, whereas Runx2 and Mmp13 were upregulated by 2-mm elongation. Apoptosis was inhibited by low stress. The results of this study suggested that 1-mm elongation can maintain the structure of the enthesis, while 2-mm elongation promotes degenerative changes.
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Affiliation(s)
- Taichi Saito
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Ryo Nakamichi
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.,Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | - Aki Yoshida
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Takaaki Hiranaka
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Yuki Okazaki
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Satoshi Nezu
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Minami Matsuhashi
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Yasunori Shimamura
- Department of Sports Medicine, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Takayuki Furumatsu
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Keiichiro Nishida
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Toshifumi Ozaki
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
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12
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Benage LG, Sweeney JD, Giers MB, Balasubramanian R. Dynamic Load Model Systems of Tendon Inflammation and Mechanobiology. Front Bioeng Biotechnol 2022; 10:896336. [PMID: 35910030 PMCID: PMC9335371 DOI: 10.3389/fbioe.2022.896336] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 06/22/2022] [Indexed: 11/25/2022] Open
Abstract
Dynamic loading is a shared feature of tendon tissue homeostasis and pathology. Tendon cells have the inherent ability to sense mechanical loads that initiate molecular-level mechanotransduction pathways. While mature tendons require physiological mechanical loading in order to maintain and fine tune their extracellular matrix architecture, pathological loading initiates an inflammatory-mediated tissue repair pathway that may ultimately result in extracellular matrix dysregulation and tendon degeneration. The exact loading and inflammatory mechanisms involved in tendon healing and pathology is unclear although a precise understanding is imperative to improving therapeutic outcomes of tendon pathologies. Thus, various model systems have been designed to help elucidate the underlying mechanisms of tendon mechanobiology via mimicry of the in vivo tendon architecture and biomechanics. Recent development of model systems has focused on identifying mechanoresponses to various mechanical loading platforms. Less effort has been placed on identifying inflammatory pathways involved in tendon pathology etiology, though inflammation has been implicated in the onset of such chronic injuries. The focus of this work is to highlight the latest discoveries in tendon mechanobiology platforms and specifically identify the gaps for future work. An interdisciplinary approach is necessary to reveal the complex molecular interplay that leads to tendon pathologies and will ultimately identify potential regenerative therapeutic targets.
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Affiliation(s)
- Lindsay G. Benage
- School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR, United States
| | - James D. Sweeney
- School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR, United States
| | - Morgan B. Giers
- School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR, United States
- *Correspondence: Morgan B. Giers,
| | - Ravi Balasubramanian
- School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR, United States
- School of Mechanical, Industrial and Manufacturing Engineering, Oregon State University, Corvallis, OR, United States
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Wilks BT, Evans EB, Howes A, Hopkins CM, Nakhla MN, Williams G, Morgan JR. Quantifying Cell-Derived Changes in Collagen Synthesis, Alignment, and Mechanics in a 3D Connective Tissue Model. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2103939. [PMID: 35102708 PMCID: PMC8981917 DOI: 10.1002/advs.202103939] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 12/06/2021] [Indexed: 06/14/2023]
Abstract
Dysregulation of extracellular matrix (ECM) synthesis, organization, and mechanics are hallmark features of diseases like fibrosis and cancer. However, most in vitro models fail to recapitulate the three-dimensional (3D) multi-scale hierarchical architecture of collagen-rich tissues and as a result, are unable to mirror native or disease phenotypes. Herein, using primary human fibroblasts seeded into custom fabricated 3D non-adhesive agarose molds, a novel strategy is proposed to direct the morphogenesis of engineered 3D ring-shaped tissue constructs with tensile and histological properties that recapitulate key features of fibrous connective tissue. To characterize the shift from monodispersed cells to a highly-aligned, collagen-rich matrix, a multi-modal approach integrating histology, multiphoton second-harmonic generation, and electron microscopy is employed. Structural changes in collagen synthesis and alignment are then mapped to functional differences in tissue mechanics and total collagen content. Due to the absence of an exogenously added scaffolding material, this model enables the direct quantification of cell-derived changes in 3D matrix synthesis, alignment, and mechanics in response to the addition or removal of relevant biomolecular perturbations. To illustrate this, the effects of nutrient composition, fetal bovine serum, rho-kinase inhibitor, and pro- and anti-fibrotic compounds on ECM synthesis, 3D collagen architecture, and mechanophenotype are quantified.
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Affiliation(s)
- Benjamin T. Wilks
- Center for Biomedical EngineeringBrown UniversityProvidenceRI02129USA
- Center for Alternatives to Animals in TestingBrown UniversityProvidenceRI02129USA
- Present address:
Center for Engineering in Medicine & SurgeryHarvard Medical School & Massachusetts General HospitalBostonMA02114USA
| | | | - Andrew Howes
- Department of Molecular BiologyCell Biology & BiochemistryBrown UniversityProvidenceRI02129USA
| | - Caitlin M. Hopkins
- Center for Alternatives to Animals in TestingBrown UniversityProvidenceRI02129USA
- Department of Pathology & Laboratory MedicineBrown UniversityProvidenceRI02129USA
| | - Morcos N. Nakhla
- Department of Pathology & Laboratory MedicineBrown UniversityProvidenceRI02129USA
| | - Geoffrey Williams
- Department of Molecular BiologyCell Biology & BiochemistryBrown UniversityProvidenceRI02129USA
| | - Jeffrey R. Morgan
- Center for Biomedical EngineeringBrown UniversityProvidenceRI02129USA
- Center for Alternatives to Animals in TestingBrown UniversityProvidenceRI02129USA
- Department of Pathology & Laboratory MedicineBrown UniversityProvidenceRI02129USA
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14
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Wu SY, Kim W, Kremen TJ. In Vitro Cellular Strain Models of Tendon Biology and Tenogenic Differentiation. Front Bioeng Biotechnol 2022; 10:826748. [PMID: 35242750 PMCID: PMC8886160 DOI: 10.3389/fbioe.2022.826748] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/17/2022] [Indexed: 11/19/2022] Open
Abstract
Research has shown that the surrounding biomechanical environment plays a significant role in the development, differentiation, repair, and degradation of tendon, but the interactions between tendon cells and the forces they experience are complex. In vitro mechanical stimulation models attempt to understand the effects of mechanical load on tendon and connective tissue progenitor cells. This article reviews multiple mechanical stimulation models used to study tendon mechanobiology and provides an overview of the current progress in modelling the complex native biomechanical environment of tendon. Though great strides have been made in advancing the understanding of the role of mechanical stimulation in tendon development, damage, and repair, there exists no ideal in vitro model. Further comparative studies and careful consideration of loading parameters, cell populations, and biochemical additives may further offer new insight into an ideal model for the support of tendon regeneration studies.
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Affiliation(s)
- Shannon Y. Wu
- David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Won Kim
- Department of Rehabilitation Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Thomas J. Kremen
- Department of Orthopaedic Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
- *Correspondence: Thomas J. Kremen Jr,
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15
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Chae S, Choi YJ, Cho DW. Mechanically and biologically promoted cell-laden constructs generated using tissue-specific bioinks for tendon/ligament tissue engineering applications. Biofabrication 2022; 14. [PMID: 35086074 DOI: 10.1088/1758-5090/ac4fb6] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 01/27/2022] [Indexed: 11/11/2022]
Abstract
Tendon and ligament tissues provide stability and mobility crucial for musculoskeletal function, but are particularly prone to injury. Owing to poor innate healing capacity, the regeneration of mature and functional tendon/ligament (T/L) poses a formidable clinical challenge. Advanced bioengineering strategies to develop biomimetic tissue implants are highly desired for the treatment of T/L injuries. Here, we presented a cell-based tissue engineering strategy to generate cell-laden tissue constructs comprising stem cells and tissue-specific bioinks using 3D cell-printing technology. We implemented an in vitro preconditioning approach to guide semi-organized T/L-like formation before the in vivo application of cell-printed implants. During in vitro maturation, tissue-specific decellularized extracellular matrix-based cellular constructs facilitated long-term in vitro culture with high cell viability and promoted tenogenesis with enhanced cellular/structural anisotropy. Moreover, we demonstrated improved cell survival/retention upon in vivo implantation of pre-matured constructs in nude mice with de novo tendon formation and improved mechanical strength. Although in vivo mechanical properties of the cell-printed implants were lower than those of human T/L tissues, the results of this study may have significant implications for future cell-based therapies in tendon and ligament regeneration and translational medicine.
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Affiliation(s)
- Suhun Chae
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Kyungbuk 790-784, Gyeongsangbuk-do, Pohang, Gyeongsangbuk-do, 37679, Korea (the Republic of)
| | - Yeong-Jin Choi
- Department of Advanced Biomaterials Research, Korea Institute of Materials Science, 797, Changwon-daero, Seongsan-gu, Gyeongsangnam-do, Changwon, 51508, Korea (the Republic of)
| | - Dong-Woo Cho
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Kyungbuk 790-784, KOREA, Pohang, 37673, Korea (the Republic of)
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16
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Chen CH, Li DL, Chuang ADC, Dash BS, Chen JP. Tension Stimulation of Tenocytes in Aligned Hyaluronic Acid/Platelet-Rich Plasma-Polycaprolactone Core-Sheath Nanofiber Membrane Scaffold for Tendon Tissue Engineering. Int J Mol Sci 2021; 22:ijms222011215. [PMID: 34681872 PMCID: PMC8537129 DOI: 10.3390/ijms222011215] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/13/2021] [Accepted: 10/15/2021] [Indexed: 02/06/2023] Open
Abstract
To recreate the in vivo niche for tendon tissue engineering in vitro, the characteristics of tendon tissue underlines the use of biochemical and biophysical cues during tenocyte culture. Herein, we prepare core-sheath nanofibers with polycaprolactone (PCL) sheath for mechanical support and hyaluronic acid (HA)/platelet-rich plasma (PRP) core for growth factor delivery. Three types of core-sheath nanofiber membrane scaffolds (CSNMS), consisting of random HA-PCL nanofibers (Random), random HA/PRP-PCL nanofibers (Random+) or aligned HA/PRP-PCL (Align+) nanofibers, were used to study response of rabbit tenocytes to biochemical (PRP) and biophysical (fiber alignment) stimulation. The core-sheath structures as well as other pertinent properties of CSNMS have been characterized, with Align+ showing the best mechanical properties. The unidirectional growth of tenocytes, as induced by aligned fiber topography, was confirmed from cell morphology and cytoskeleton expression. The combined effects of PRP and fiber alignment in Align+ CSNMS lead to enhanced cell proliferation rates, as well as upregulated gene expression and marker protein synthesis. Another biophysical cue on tenocytes was introduced by dynamic culture of tenocyte-seeded Align+ in a bioreactor with cyclic tension stimulation. Augmented by this biophysical beacon from mechanical loading, dynamic cell culture could shorten the time for tendon maturation in vitro, with improved cell proliferation rates and tenogenic phenotype maintenance, compared to static culture. Therefore, we successfully demonstrate how combined use of biochemical/topographical cues as well as mechanical stimulation could ameliorate cellular response of tenocytes in CSNMS, which can provide a functional in vitro environmental niche for tendon tissue engineering.
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Affiliation(s)
- Chih-Hao Chen
- Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital at Keelung, Keelung 20401, Taiwan; (C.-H.C.); (A.D.-C.C.)
- Department of Plastic and Reconstructive Surgery and Craniofacial Research Center, Chang Gung Memorial Hospital at Linkou, Collage of Medicine, Chang Gung University, Taoyuan 33305, Taiwan
- Department of Chemical and Materials Engineering, Chang Gung University, Taoyuan 33302, Taiwan; (D.-L.L.); (B.S.D.)
| | - Dai-Ling Li
- Department of Chemical and Materials Engineering, Chang Gung University, Taoyuan 33302, Taiwan; (D.-L.L.); (B.S.D.)
| | - Andy Deng-Chi Chuang
- Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital at Keelung, Keelung 20401, Taiwan; (C.-H.C.); (A.D.-C.C.)
| | - Banendu Sunder Dash
- Department of Chemical and Materials Engineering, Chang Gung University, Taoyuan 33302, Taiwan; (D.-L.L.); (B.S.D.)
| | - Jyh-Ping Chen
- Department of Plastic and Reconstructive Surgery and Craniofacial Research Center, Chang Gung Memorial Hospital at Linkou, Collage of Medicine, Chang Gung University, Taoyuan 33305, Taiwan
- Department of Chemical and Materials Engineering, Chang Gung University, Taoyuan 33302, Taiwan; (D.-L.L.); (B.S.D.)
- Research Center for Food and Cosmetic Safety, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 33305, Taiwan
- Department of Materials Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan
- Correspondence: ; Tel.: +886-3211-8800
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17
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Klatte-Schulz F, Bormann N, Voss I, Melzer J, Schmock A, Bucher CH, Thiele K, Moroder P, Haffner-Luntzer M, Ignatius A, Duda GN, Wildemann B. Bursa-Derived Cells Show a Distinct Mechano-Response to Physiological and Pathological Loading in vitro. Front Cell Dev Biol 2021; 9:657166. [PMID: 34136480 PMCID: PMC8201779 DOI: 10.3389/fcell.2021.657166] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 04/09/2021] [Indexed: 11/13/2022] Open
Abstract
The mechano-response of highly loaded tissues such as bones or tendons is well investigated, but knowledge regarding the mechano-responsiveness of adjacent tissues such as the subacromial bursa is missing. For a better understanding of the physiological role of the bursa as a friction-reducing structure in the joint, the study aimed to analyze whether and how bursa-derived cells respond to physiological and pathological mechanical loading. This might help to overcome some of the controversies in the field regarding the role of the bursa in the development and healing of shoulder pathologies. Cells of six donors seeded on collagen-coated silicon dishes were stimulated over 3 days for 1 or 4 h with 1, 5, or 10% strain. Orientation of the actin cytoskeleton, YAP nuclear translocation, and activation of non-muscle myosin II (NMM-II) were evaluated for 4 h stimulations to get a deeper insight into mechano-transduction processes. To investigate the potential of bursa-derived cells to adapt their matrix formation and remodeling according to mechanical loading, outcome measures included cell viability, gene expression of extracellular matrix and remodeling markers, and protein secretions. The orientation angle of the actin cytoskeleton increased toward a more perpendicular direction with increased loading and lowest variations for the 5% loading group. With 10% tension load, cells were visibly stressed, indicated by loss in actin density and slightly reduced cell viability. A significantly increased YAP nuclear translocation occurred for the 1% loading group with a similar trend for the 5% group. NMM-II activation was weak for all stimulation conditions. On the gene expression level, only the expression of TIMP2 was down-regulated in the 1 h group compared to control. On the protein level, collagen type I and MMP2 increased with higher/longer straining, respectively, whereas TIMP1 secretion was reduced, resulting in an MMP/TIMP imbalance. In conclusion, this study documents for the first time a clear mechano-responsiveness in bursa-derived cells with activation of mechano-transduction pathways and thus hint to a physiological function of mechanical loading in bursa-derived cells. This study represents the basis for further investigations, which might lead to improved treatment options of subacromial bursa-related pathologies in the future.
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Affiliation(s)
- Franka Klatte-Schulz
- Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany.,BIH Center for Regenerative Therapies (BCRT), Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Nicole Bormann
- Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany.,BIH Center for Regenerative Therapies (BCRT), Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Isabel Voss
- Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Josephine Melzer
- Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Aysha Schmock
- Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany.,BIH Center for Regenerative Therapies (BCRT), Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Christian H Bucher
- Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany.,BIH Center for Regenerative Therapies (BCRT), Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Kathi Thiele
- Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Philipp Moroder
- Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | | | - Anita Ignatius
- Institute of Orthopaedic Research and Biomechanics, Ulm University, Ulm, Germany
| | - Georg N Duda
- Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany.,BIH Center for Regenerative Therapies (BCRT), Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Britt Wildemann
- Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany.,Experimental Trauma Surgery, Department of Trauma-, Hand- and Reconstructive Surgery, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
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18
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Meeremans M, Van de Walle GR, Van Vlierberghe S, De Schauwer C. The Lack of a Representative Tendinopathy Model Hampers Fundamental Mesenchymal Stem Cell Research. Front Cell Dev Biol 2021; 9:651164. [PMID: 34012963 PMCID: PMC8126669 DOI: 10.3389/fcell.2021.651164] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 04/06/2021] [Indexed: 12/13/2022] Open
Abstract
Overuse tendon injuries are a major cause of musculoskeletal morbidity in both human and equine athletes, due to the cumulative degenerative damage. These injuries present significant challenges as the healing process often results in the formation of inferior scar tissue. The poor success with conventional therapy supports the need to search for novel treatments to restore functionality and regenerate tissue as close to native tendon as possible. Mesenchymal stem cell (MSC)-based strategies represent promising therapeutic tools for tendon repair in both human and veterinary medicine. The translation of tissue engineering strategies from basic research findings, however, into clinical use has been hampered by the limited understanding of the multifaceted MSC mechanisms of action. In vitro models serve as important biological tools to study cell behavior, bypassing the confounding factors associated with in vivo experiments. Controllable and reproducible in vitro conditions should be provided to study the MSC healing mechanisms in tendon injuries. Unfortunately, no physiologically representative tendinopathy models exist to date. A major shortcoming of most currently available in vitro tendon models is the lack of extracellular tendon matrix and vascular supply. These models often make use of synthetic biomaterials, which do not reflect the natural tendon composition. Alternatively, decellularized tendon has been applied, but it is challenging to obtain reproducible results due to its variable composition, less efficient cell seeding approaches and lack of cell encapsulation and vascularization. The current review will overview pros and cons associated with the use of different biomaterials and technologies enabling scaffold production. In addition, the characteristics of the ideal, state-of-the-art tendinopathy model will be discussed. Briefly, a representative in vitro tendinopathy model should be vascularized and mimic the hierarchical structure of the tendon matrix with elongated cells being organized in a parallel fashion and subjected to uniaxial stretching. Incorporation of mechanical stimulation, preferably uniaxial stretching may be a key element in order to obtain appropriate matrix alignment and create a pathophysiological model. Together, a thorough discussion on the current status and future directions for tendon models will enhance fundamental MSC research, accelerating translation of MSC therapies for tendon injuries from bench to bedside.
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Affiliation(s)
- Marguerite Meeremans
- Comparative Physiology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Gerlinde R Van de Walle
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - Sandra Van Vlierberghe
- Polymer Chemistry and Biomaterials Group, Centre of Macromolecular Chemistry, Faculty of Sciences, Ghent University, Ghent, Belgium
| | - Catharina De Schauwer
- Comparative Physiology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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19
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Meeremans M, Van Damme L, De Spiegelaere W, Van Vlierberghe S, De Schauwer C. Equine Tenocyte Seeding on Gelatin Hydrogels Improves Elongated Morphology. Polymers (Basel) 2021; 13:747. [PMID: 33670848 PMCID: PMC7957613 DOI: 10.3390/polym13050747] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 02/24/2021] [Accepted: 02/24/2021] [Indexed: 12/12/2022] Open
Abstract
(1) Background: Tendinopathy is a common injury in both human and equine athletes. Representative in vitro models are mandatory to facilitate translation of fundamental research into successful clinical treatments. Natural biomaterials like gelatin provide favorable cell binding characteristics and are easily modifiable. In this study, methacrylated gelatin (gel-MA) and norbornene-functionalized gelatin (gel-NB), crosslinked with 1,4-dithiotreitol (DTT) or thiolated gelatin (gel-SH) were compared. (2) Methods: The physicochemical properties (1H-NMR spectroscopy, gel fraction, swelling ratio, and storage modulus) and equine tenocyte characteristics (proliferation, viability, and morphology) of four different hydrogels (gel-MA, gel-NB85/DTT, gel-NB55/DTT, and gel-NB85/SH75) were evaluated. Cellular functionality was analyzed using fluorescence microscopy (viability assay and focal adhesion staining). (3) Results: The thiol-ene based hydrogels showed a significantly lower gel fraction/storage modulus and a higher swelling ratio compared to gel-MA. Significantly less tenocytes were observed on gel-MA discs at 14 days compared to gel-NB85/DTT, gel-NB55/DTT and gel-NB85/SH75. At 7 and 14 days, the characteristic elongated morphology of tenocytes was significantly more pronounced on gel-NB85/DTT and gel-NB55/DTT in contrast to TCP and gel-MA. (4) Conclusions: Thiol-ene crosslinked gelatins exploiting DTT as a crosslinker are the preferred biomaterials to support the culture of tenocytes. Follow-up experiments will evaluate these biomaterials in more complex models.
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Affiliation(s)
- Marguerite Meeremans
- Comparative Physiology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium;
| | - Lana Van Damme
- Polymer Chemistry and Biomaterials Group, Centre of Macromolecular Chemistry, Faculty of Sciences, Ghent University, Krijgslaan 281 S4-Bis, B-9000 Ghent, Belgium; (L.V.D.); (S.V.V.)
| | - Ward De Spiegelaere
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium;
| | - Sandra Van Vlierberghe
- Polymer Chemistry and Biomaterials Group, Centre of Macromolecular Chemistry, Faculty of Sciences, Ghent University, Krijgslaan 281 S4-Bis, B-9000 Ghent, Belgium; (L.V.D.); (S.V.V.)
| | - Catharina De Schauwer
- Comparative Physiology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium;
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20
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Chen P, Chen Z, Mitchell C, Gao J, Chen L, Wang A, Leys T, Landao-Bassonga E, Zheng Q, Wang T, Zheng M. Intramuscular injection of Botox causes tendon atrophy by induction of senescence of tendon-derived stem cells. Stem Cell Res Ther 2021; 12:38. [PMID: 33413592 PMCID: PMC7791643 DOI: 10.1186/s13287-020-02084-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 12/07/2020] [Indexed: 01/04/2023] Open
Abstract
Background Botulinum toxin (Botox) injection is in widespread clinical use for the treatment of muscle spasms and tendinopathy but the mechanism of action is poorly understood. Hypothesis We hypothesised that the reduction of patellar-tendon mechanical-loading following intra-muscular injection of Botox results in tendon atrophy that is at least in part mediated by the induction of senescence of tendon-derived stem cells (TDSCs). Study design Controlled laboratory study Methods A total of 36 mice were randomly divided into 2 groups (18 Botox-injected and 18 vehicle-only control). Mice were injected into the right vastus lateralis of quadriceps muscles either with Botox (to induce mechanical stress deprivation of the patellar tendon) or with normal saline as a control. At 2 weeks post-injection, animals were euthanized prior to tissues being harvested for either evaluation of tendon morphology or in vitro studies. TDSCs were isolated by cell-sorting prior to determination of viability, differentiation capacity or the presence of senescence markers, as well as assessing their response to mechanical loading in a bioreactor. Finally, to examine the mechanism of tendon atrophy in vitro, the PTEN/AKT-mediated cell senescence pathway was evaluated in TDSCs from both groups. Results Two weeks after Botox injection, patellar tendons displayed several atrophic features including tissue volume reduction, collagen fibre misalignment and increased degradation. A colony formation assay revealed a significantly reduced number of colony forming units of TDSCs in the Botox-injected group compared to controls. Multipotent differentiation capacities of TDSCs were also diminished after Botox injection. To examine if mechanically deprived TDSC are capable of forming tendon tissue, we used an isolated bioreactor system to culture tendon constructs using TDSC. These results showed that TDSCs from the Botox-treated group failed to restore tenogenic differentiation after appropriate mechanical loading. Examination of the signalling pathway revealed that injection of Botox into quadriceps muscles causes PTEN/AKT-mediated cell senescence of TDSCs. Conclusion Intramuscular injection of Botox interferes with tendon homeostasis by inducing tendon atrophy and senescence of TDSCs. Botox injection may have long-term adverse consequences for the treatment of tendinopathy. Clinical relevance Intramuscular Botox injection for tendinopathy or tendon injury could result in adverse effects in human tendons and evaluation of its long-term efficacy is warranted.
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Affiliation(s)
- Peilin Chen
- Center for Orthopaedic Translational Research, Medical School, University of Western Australia, Nedlands, Australia
| | - Ziming Chen
- Center for Orthopaedic Translational Research, Medical School, University of Western Australia, Nedlands, Australia
| | - Christopher Mitchell
- Center for Orthopaedic Translational Research, Medical School, University of Western Australia, Nedlands, Australia
| | - Junjie Gao
- Perron Institute for Neurological and Translational Science, Perth, Western Australia, Australia
| | - Lianzhi Chen
- Center for Orthopaedic Translational Research, Medical School, University of Western Australia, Nedlands, Australia
| | - Allan Wang
- Center for Orthopaedic Translational Research, Medical School, University of Western Australia, Nedlands, Australia.,Medical School, University of Notre Dame, Fremantle, Western Australia, Australia
| | - Toby Leys
- Department of Orthopaedics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Euphemie Landao-Bassonga
- Center for Orthopaedic Translational Research, Medical School, University of Western Australia, Nedlands, Australia.,Perron Institute for Neurological and Translational Science, Perth, Western Australia, Australia
| | - Qiujian Zheng
- Division of Orthopaedic Surgery, Department of Surgery, Guangdong General Hospital, Guangdong Academy of Medical Science, Guangzhou, Guangdong, China.
| | - Tao Wang
- Center for Orthopaedic Translational Research, Medical School, University of Western Australia, Nedlands, Australia. .,Division of Orthopaedic Surgery, Department of Surgery, Guangdong General Hospital, Guangdong Academy of Medical Science, Guangzhou, Guangdong, China.
| | - Minghao Zheng
- Center for Orthopaedic Translational Research, Medical School, University of Western Australia, Nedlands, Australia. .,Perron Institute for Neurological and Translational Science, Perth, Western Australia, Australia.
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21
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Smit TH. Adolescent idiopathic scoliosis: The mechanobiology of differential growth. JOR Spine 2020; 3:e1115. [PMID: 33392452 PMCID: PMC7770204 DOI: 10.1002/jsp2.1115] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 07/02/2020] [Indexed: 12/16/2022] Open
Abstract
Adolescent idiopathic scoliosis (AIS) has been linked to neurological, genetic, hormonal, microbial, and environmental cues. Physically, however, AIS is a structural deformation, hence an adequate theory of etiology must provide an explanation for the forces involved. Earlier, we proposed differential growth as a possible mechanism for the slow, three-dimensional deformations observed in AIS. In the current perspective paper, the underlying mechanobiology of cells and tissues is explored. The musculoskeletal system is presented as a tensegrity-like structure, in which the skeletal compressive elements are stabilized by tensile muscles, ligaments, and fasciae. The upright posture of the human spine requires minimal muscular energy, resulting in less compression, and stability than in quadrupeds. Following Hueter-Volkmann Law, less compression allows for faster growth of vertebrae and intervertebral discs. The substantially larger intervertebral disc height observed in AIS patients suggests high intradiscal pressure, a condition favorable for notochordal cells; this promotes the production of proteoglycans and thereby osmotic pressure. Intradiscal pressure overstrains annulus fibrosus and longitudinal ligaments, which are then no longer able to remodel and grow, and consequently induce differential growth. Intradiscal pressure thus is proposed as the driver of AIS and may therefore be a promising target for prevention and treatment.
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Affiliation(s)
- Theodoor H. Smit
- Department of Orthopaedic SurgeryAmsterdam Movement Sciences, Amsterdam University Medical CentresAmsterdamNetherlands
- Department of Medical BiologyAmsterdam University Medical CentresAmsterdamNetherlands
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The Application of Mechanical Stimulations in Tendon Tissue Engineering. Stem Cells Int 2020; 2020:8824783. [PMID: 33029149 PMCID: PMC7532391 DOI: 10.1155/2020/8824783] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/22/2020] [Accepted: 08/25/2020] [Indexed: 12/18/2022] Open
Abstract
Tendon injury is the most common disease in the musculoskeletal system. The current treatment methods have many limitations, such as poor therapeutic effects, functional loss of donor site, and immune rejection. Tendon tissue engineering provides a new treatment strategy for tendon repair and regeneration. In this review, we made a retrospective analysis of applying mechanical stimulation in tendon tissue engineering, and its potential as a direction of development for future clinical treatment strategies. For this purpose, the following topics are discussed; (1) the context of tendon tissue engineering and mechanical stimulation; (2) the applications of various mechanical stimulations in tendon tissue engineering, as well as their inherent mechanisms; (3) the application of magnetic force and the synergy of mechanical and biochemical stimulation. With this, we aim at clarifying some of the main questions that currently exist in the field of tendon tissue engineering and consequently gain new knowledge that may help in the development of future clinical application of tissue engineering in tendon injury.
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Jaiswal D, Yousman L, Neary M, Fernschild E, Zolnoski B, Katebifar S, Rudraiah S, Mazzocca AD, Kumbar SG. Tendon tissue engineering: biomechanical considerations. Biomed Mater 2020; 15:052001. [DOI: 10.1088/1748-605x/ab852f] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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24
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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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In Vivo and In Vitro Mechanical Loading of Mouse Achilles Tendons and Tenocytes-A Pilot Study. Int J Mol Sci 2020; 21:ijms21041313. [PMID: 32075290 PMCID: PMC7072865 DOI: 10.3390/ijms21041313] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 02/05/2020] [Accepted: 02/10/2020] [Indexed: 12/21/2022] Open
Abstract
Mechanical force is a key factor for the maintenance, adaptation, and function of tendons. Investigating the impact of mechanical loading in tenocytes and tendons might provide important information on in vivo tendon mechanobiology. Therefore, the study aimed at understanding if an in vitro loading set up of tenocytes leads to similar regulations of cell shape and gene expression, as loading of the Achilles tendon in an in vivo mouse model. In vivo: The left tibiae of mice (n = 12) were subject to axial cyclic compressive loading for 3 weeks, and the Achilles tendons were harvested. The right tibiae served as the internal non-loaded control. In vitro: tenocytes were isolated from mice Achilles tendons and were loaded for 4 h or 5 days (n = 6 per group) based on the in vivo protocol. Histology showed significant differences in the cell shape between in vivo and in vitro loading. On the molecular level, quantitative real-time PCR revealed significant differences in the gene expression of collagen type I and III and of the matrix metalloproteinases (MMP). Tendon-associated markers showed a similar expression profile. This study showed that the gene expression of tendon markers was similar, whereas significant changes in the expression of extracellular matrix (ECM) related genes were detected between in vivo and in vitro loading. This first pilot study is important for understanding to which extent in vitro stimulation set-ups of tenocytes can mimic in vivo characteristics.
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26
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Sawadkar P, Player D, Bozec L, Mudera V. The mechanobiology of tendon fibroblasts under static and uniaxial cyclic load in a 3D tissue engineered model mimicking native extracellular matrix. J Tissue Eng Regen Med 2019; 14:135-146. [PMID: 31622052 DOI: 10.1002/term.2975] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 08/29/2019] [Accepted: 09/26/2019] [Indexed: 01/05/2023]
Abstract
Tendon mechanobiology plays a vital role in tendon repair and regeneration; however, this mechanism is currently poorly understood. We tested the role of different mechanical loads on extracellular matrix (ECM) remodelling gene expression and the morphology of tendon fibroblasts in collagen hydrogels, designed to mimic native tissue. Hydrogels were subjected to precise static or uniaxial loading patterns of known magnitudes and sampled to analyse gene expression of known mechano-responsive ECM-associated genes (Collagen I, Collagen III, Tenomodulin, and TGF-β). Tendon fibroblast cytomechanics was studied under load by using a tension culture force monitor, with immunofluorescence and immunohistological staining used to examine cell morphology. Tendon fibroblasts subjected to cyclic load showed that endogenous matrix tension was maintained, with significant concomitant upregulation of ECM remodelling genes, Collagen I, Collagen III, Tenomodulin, and TGF-β when compared with static load and control samples. These data indicate that tendon fibroblasts acutely adapt to the mechanical forces placed upon them, transmitting forces across the ECM without losing mechanical dynamism. This model demonstrates cell-material (ECM) interaction and remodelling in preclinical a platform, which can be used as a screening tool to understand tendon regeneration.
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Affiliation(s)
- Prasad Sawadkar
- Division of Surgery and interventional Science, UCL Stanmore campus, London, UK
| | - Darren Player
- Division of Surgery and interventional Science, UCL Stanmore campus, London, UK
| | - Laurent Bozec
- Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, London, UK
| | - Vivek Mudera
- Division of Surgery and interventional Science, UCL Stanmore campus, London, UK
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27
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Zhang C, Zhu J, Zhou Y, Thampatty BP, Wang JHC. Tendon Stem/Progenitor Cells and Their Interactions with Extracellular Matrix and Mechanical Loading. Stem Cells Int 2019; 2019:3674647. [PMID: 31737075 PMCID: PMC6815631 DOI: 10.1155/2019/3674647] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 08/04/2019] [Accepted: 08/17/2019] [Indexed: 12/11/2022] Open
Abstract
Tendons are unique connective tissues in the sense that their biological properties are largely determined by their tendon-specific stem cells, extracellular matrix (ECM) surrounding the stem cells, mechanical loading conditions placed on the tendon, and the complex interactions among them. This review is aimed at providing an overview of recent advances in the identification and characterization of tendon stem/progenitor cells (TSPCs) and their interactions with ECM and mechanical loading. In addition, the effects of such interactions on the maintenance of tendon homeostasis and the initiation of tendon pathological conditions are discussed. Moreover, the challenges in further investigations of TSPC mechanobiology in vitro and in vivo are outlined. Finally, future research efforts are suggested, which include using specific gene knockout models and single-cell transcription profiling to enable a broad and deep understanding of the physiology and pathophysiology of tendons.
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Affiliation(s)
- Chuanxin Zhang
- Joint Surgery and Sports Medicine Department, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Jun Zhu
- Joint Surgery and Sports Medicine Department, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Yiqin Zhou
- Joint Surgery and Sports Medicine Department, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Bhavani P. Thampatty
- MechanoBiology Laboratory, Departments of Orthopaedic Surgery, Bioengineering, and Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - James H-C. Wang
- MechanoBiology Laboratory, Departments of Orthopaedic Surgery, Bioengineering, and Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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28
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Parks AN, Nahata J, Edouard NE, Temenoff JS, Platt MO. Sequential, but not Concurrent, Incubation of Cathepsin K and L with Type I Collagen Results in Extended Proteolysis. Sci Rep 2019; 9:5399. [PMID: 30931961 PMCID: PMC6443789 DOI: 10.1038/s41598-019-41782-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 03/13/2019] [Indexed: 01/13/2023] Open
Abstract
Degradation of extracellular matrix (ECM) during tendinopathy is, in part, mediated by the collagenolytic cathepsin K (catK) and cathepsin L (catL), with a temporal component to their activity. The objective of this study was to determine how catK and catL act in concert or in conflict to degrade collagen and tendon ECM during tissue degeneration. To do so, type I collagen gels or ECM extracted from apolipoprotein E deficient mouse Achilles tendons were incubated with catK and catL either concurrently or sequentially, incubating catK first, then catL after a delayed time period. Sequential incubation of catK then catL caused greater degradation of substrates over concurrent incubation, and of either cathepsin alone. Zymography showed there were reduced amounts of active enzymes when co-incubated, indicating that cannibalism, or protease-on-protease degradation between catK and catL was occurring, but incubation with ECM could distract from these interactions. CatK alone was sufficient to quickly degrade tendon ECM, but catL was not, requiring the presence of catK for degradation. Together, these data identify cooperative and conflicting actions of cathepsin mediated collagen matrix degradation by considering interactive effects of multiple proteases during tissue degeneration.
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Affiliation(s)
- Akia N Parks
- W.H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Dr NW, Atlanta, GA, 30332, USA
| | - Juhi Nahata
- W.H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Dr NW, Atlanta, GA, 30332, USA
| | - Naomi-Eliana Edouard
- Mathematics Department, Spelman College, 350 Spelman Ln, Atlanta, GA, 30314, USA
| | - Johnna S Temenoff
- W.H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Dr NW, Atlanta, GA, 30332, USA.,Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Dr NW, Atlanta, GA, 30332, USA
| | - Manu O Platt
- W.H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Dr NW, Atlanta, GA, 30332, USA. .,Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Dr NW, Atlanta, GA, 30332, USA.
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29
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Szczesny SE, Aeppli C, David A, Mauck RL. Fatigue loading of tendon results in collagen kinking and denaturation but does not change local tissue mechanics. J Biomech 2018. [PMID: 29519673 DOI: 10.1016/j.jbiomech.2018.02.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Fatigue loading is a primary cause of tendon degeneration, which is characterized by the disruption of collagen fibers and the appearance of abnormal (e.g., cartilaginous, fatty, calcified) tissue deposits. The formation of such abnormal deposits, which further weakens the tissue, suggests that resident tendon cells acquire an aberrant phenotype in response to fatigue damage and the resulting altered mechanical microenvironment. While fatigue loading produces clear changes in collagen organization and molecular denaturation, no data exist regarding the effect of fatigue on the local tissue mechanical properties. Therefore, the objective of this study was to identify changes in the local tissue stiffness of tendons after fatigue loading. We hypothesized that fatigue damage would reduce local tissue stiffness, particularly in areas with significant structural damage (e.g., collagen denaturation). We tested this hypothesis by identifying regions of local fatigue damage (i.e., collagen fiber kinking and molecular denaturation) via histologic imaging and by measuring the local tissue modulus within these regions via atomic force microscopy (AFM). Counter to our initial hypothesis, we found no change in the local tissue modulus as a consequence of fatigue loading, despite widespread fiber kinking and collagen denaturation. These data suggest that immediate changes in topography and tissue structure - but not local tissue mechanics - initiate the early changes in tendon cell phenotype as a consequence of fatigue loading that ultimately culminate in tendon degeneration.
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Affiliation(s)
- Spencer E Szczesny
- Department of Orthopaedic Surgery, University of Pennsylvania, 110 Stemmler Hall, 36th Street & Hamilton Walk, Philadelphia, PA 19104, United States; Department of Biomedical Engineering, Department of Orthopaedics and Rehabilitation, Pennsylvania State University, 205 Hallowell Building, University Park, PA 16802, United States.
| | - Céline Aeppli
- Eidgenössische Technische Hochschule, Rämistrasse 101, 8092 Zürich, Switzerland
| | - Alexander David
- Department of Bioengineering, 240 Skirkanich Hall, 210 South 33rd Street, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Robert L Mauck
- Department of Orthopaedic Surgery, University of Pennsylvania, 110 Stemmler Hall, 36th Street & Hamilton Walk, Philadelphia, PA 19104, United States; Department of Bioengineering, 240 Skirkanich Hall, 210 South 33rd Street, University of Pennsylvania, Philadelphia, PA 19104, United States; Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Veterans Affairs Medical Center, 3900 Woodland Avenue, Philadelphia, PA 19104, United States
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30
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Guo XE, Hung CT, Sandell LJ, Silva MJ. Musculoskeletal mechanobiology: A new era for MechanoMedicine. J Orthop Res 2018; 36:531-532. [PMID: 29409134 DOI: 10.1002/jor.23789] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- X Edward Guo
- Department of Biomedical Engineering, Columbia University, 1210 Amsterdam Avenue, New York, NY 10027
| | - Clark T Hung
- Department of Biomedical Engineering, Columbia University, 1210 Amsterdam Avenue, New York, NY 10027
| | - Linda J Sandell
- Department of Orthopaedic Surgery, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110
| | - Matthew J Silva
- Department of Orthopaedic Surgery, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110
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