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Sabetkish S, Currie P, Meagher L. Recent trends in 3D bioprinting technology for skeletal muscle regeneration. Acta Biomater 2024; 181:46-66. [PMID: 38697381 DOI: 10.1016/j.actbio.2024.04.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 04/24/2024] [Accepted: 04/25/2024] [Indexed: 05/05/2024]
Abstract
Skeletal muscle is a pro-regenerative tissue, that utilizes a tissue-resident stem cell system to effect repair upon injury. Despite the demonstrated efficiency of this system in restoring muscle mass after many acute injuries, in conditions of severe trauma such as those evident in volumetric muscle loss (VML) (>20 % by mass), this self-repair capability is unable to restore tissue architecture, requiring interventions which currently are largely surgical. As a possible alternative, the generation of artificial muscle using tissue engineering approaches may also be of importance in the treatment of VML and muscle diseases such as dystrophies. Three-dimensional (3D) bioprinting has been identified as a promising technique for regeneration of the complex architecture of skeletal muscle. This review discusses existing treatment strategies following muscle damage, recent progress in bioprinting techniques, the bioinks used for muscle regeneration, the immunogenicity of scaffold materials, and in vitro and in vivo maturation techniques for 3D bio-printed muscle constructs. The pros and cons of these bioink formulations are also highlighted. Finally, we present the current limitations and challenges in the field and critical factors to consider for bioprinting approaches to become more translationa and to produce clinically relevant engineered muscle. STATEMENT OF SIGNIFICANCE: This review discusses the physiopathology of muscle injuries and existing clinical treatment strategies for muscle damage, the types of bioprinting techniques that have been applied to bioprinting of muscle, and the bioinks commonly used for muscle regeneration. The pros and cons of these bioinks are highlighted. We present a discussion of existing gaps in the literature and critical factors to consider for the translation of bioprinting approaches and to produce clinically relevant engineered muscle. Finally, we provide insights into what we believe will be the next steps required before the realization of the application of tissue-engineered muscle in humans. We believe this manuscript is an insightful, timely, and instructive review that will guide future muscle bioprinting research from a fundamental construct creation approach, down a translational pathway to achieve the desired impact in the clinic.
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Affiliation(s)
- Shabnam Sabetkish
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia; ARC Training Centre for Cell and Tissue Engineering Technologies, Monash University, Clayton, VIC 3800, Australia
| | - Peter Currie
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia; ARC Training Centre for Cell and Tissue Engineering Technologies, Monash University, Clayton, VIC 3800, Australia
| | - Laurence Meagher
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria, Australia; ARC Training Centre for Cell and Tissue Engineering Technologies, Monash University, Clayton, VIC 3800, Australia.
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2
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Ngo TB, Josyula A, DeStefano S, Fertil D, Faust M, Lokwani R, Sadtler K. Intersection of Immunity, Metabolism, and Muscle Regeneration in an Autoimmune-Prone MRL Mouse Model. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2306961. [PMID: 38192168 PMCID: PMC10953568 DOI: 10.1002/advs.202306961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/07/2023] [Indexed: 01/10/2024]
Abstract
Due to the limited capacity of mammals to regenerate complex tissues, researchers have worked to understand the mechanisms of tissue regeneration in organisms that maintain that capacity. One example is the MRL/MpJ mouse strain with unique regenerative capacity in ear pinnae that is absent from other strains, such as the common C57BL/6 strain. The MRL/MpJ mouse has also been associated with an autoimmune phenotype even in the absence of the mutant Fas gene described in its parent strain MRL/lpr. Due to these findings, the differences between the responses of MRL/MpJ versus C57BL/6 strain are evaluated in volumetric muscle injury and subsequent material implantation. One salient feature of the MRL/MpJ response to injury is robust adipogenesis within the muscle. This is associated with a decrease in M2-like polarization in response to biologically derived extracellular matrix scaffolds. In pro-fibrotic materials, such as polyethylene, there are fewer foreign body giant cells in the MRL/MpJ mice. As there are reports of both positive and negative influences of adipose tissue and adipogenesis on wound healing, this model can provide an important lens to investigate the interplay between stem cells, adipose tissue, and immune responses in trauma and material implantation.
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Affiliation(s)
- Tran B. Ngo
- Section on ImmunoengineeringCenter for Biomedical Engineering and Technology AccelerationNational Institute of Biomedical Imaging and BioengineeringNational Institutes of HealthBethesdaMD20814USA
| | - Aditya Josyula
- Section on ImmunoengineeringCenter for Biomedical Engineering and Technology AccelerationNational Institute of Biomedical Imaging and BioengineeringNational Institutes of HealthBethesdaMD20814USA
| | - Sabrina DeStefano
- Section on ImmunoengineeringCenter for Biomedical Engineering and Technology AccelerationNational Institute of Biomedical Imaging and BioengineeringNational Institutes of HealthBethesdaMD20814USA
| | - Daphna Fertil
- Section on ImmunoengineeringCenter for Biomedical Engineering and Technology AccelerationNational Institute of Biomedical Imaging and BioengineeringNational Institutes of HealthBethesdaMD20814USA
| | - Mondreakest Faust
- Section on ImmunoengineeringCenter for Biomedical Engineering and Technology AccelerationNational Institute of Biomedical Imaging and BioengineeringNational Institutes of HealthBethesdaMD20814USA
| | - Ravi Lokwani
- Section on ImmunoengineeringCenter for Biomedical Engineering and Technology AccelerationNational Institute of Biomedical Imaging and BioengineeringNational Institutes of HealthBethesdaMD20814USA
| | - Kaitlyn Sadtler
- Section on ImmunoengineeringCenter for Biomedical Engineering and Technology AccelerationNational Institute of Biomedical Imaging and BioengineeringNational Institutes of HealthBethesdaMD20814USA
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3
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Lokwani R, Josyula A, Ngo TB, DeStefano S, Fertil D, Faust M, Adusei KM, Bhuiyan M, Lin A, Karkanitsa M, Maclean E, Fathi P, Su Y, Liu J, Vishwasrao HD, Sadtler K. Pro-regenerative biomaterials recruit immunoregulatory dendritic cells after traumatic injury. NATURE MATERIALS 2024; 23:147-157. [PMID: 37872423 DOI: 10.1038/s41563-023-01689-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 09/12/2023] [Indexed: 10/25/2023]
Abstract
During wound healing and surgical implantation, the body establishes a delicate balance between immune activation to fight off infection and clear debris and immune tolerance to control reactivity against self-tissue. Nonetheless, how such a balance is achieved is not well understood. Here we describe that pro-regenerative biomaterials for muscle injury treatment promote the proliferation of a BATF3-dependent CD103+XCR1+CD206+CD301b+ dendritic cell population associated with cross-presentation and self-tolerance. Upregulation of E-cadherin, the ligand for CD103, and XCL-1 in injured tissue suggests a mechanism for cell recruitment to trauma. Muscle injury recruited natural killer cells that produced Xcl1 when stimulated with fragmented extracellular matrix. Without cross-presenting cells, T-cell activation increases, pro-regenerative macrophage polarization decreases and there are alterations in myogenesis, adipogenesis, fibrosis and increased muscle calcification. These results, previously observed in cancer progression, suggest a fundamental mechanism of immune regulation in trauma and material implantation with implications for both short- and long-term injury recovery.
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Affiliation(s)
- Ravi Lokwani
- Section on Immunoengineering, Biomedical Engineering and Technology Acceleration Center, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Aditya Josyula
- Section on Immunoengineering, Biomedical Engineering and Technology Acceleration Center, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Tran B Ngo
- Section on Immunoengineering, Biomedical Engineering and Technology Acceleration Center, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Sabrina DeStefano
- Section on Immunoengineering, Biomedical Engineering and Technology Acceleration Center, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Daphna Fertil
- Section on Immunoengineering, Biomedical Engineering and Technology Acceleration Center, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Mondreakest Faust
- Section on Immunoengineering, Biomedical Engineering and Technology Acceleration Center, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Kenneth M Adusei
- Section on Immunoengineering, Biomedical Engineering and Technology Acceleration Center, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Minhaj Bhuiyan
- Section on Immunoengineering, Biomedical Engineering and Technology Acceleration Center, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Aaron Lin
- Section on Immunoengineering, Biomedical Engineering and Technology Acceleration Center, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
- Unit for Nanoengineering and Microphysiological Systems, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Maria Karkanitsa
- Section on Immunoengineering, Biomedical Engineering and Technology Acceleration Center, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Efua Maclean
- Section on Immunoengineering, Biomedical Engineering and Technology Acceleration Center, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Parinaz Fathi
- Section on Immunoengineering, Biomedical Engineering and Technology Acceleration Center, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
- Unit for Nanoengineering and Microphysiological Systems, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Yijun Su
- Advanced Imaging and Microscopy Resource, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Jiamin Liu
- Advanced Imaging and Microscopy Resource, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Harshad D Vishwasrao
- Advanced Imaging and Microscopy Resource, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Kaitlyn Sadtler
- Section on Immunoengineering, Biomedical Engineering and Technology Acceleration Center, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA.
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Sato H, Kohyama K, Uchibori T, Takanari K, Huard J, Badylak SF, D'Amore A, Wagner WR. Creating and Transferring an Innervated, Vascularized Muscle Flap Made from an Elastic, Cellularized Tissue Construct Developed In Situ. Adv Healthc Mater 2023; 12:e2301335. [PMID: 37499214 DOI: 10.1002/adhm.202301335] [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: 04/26/2023] [Revised: 07/21/2023] [Indexed: 07/29/2023]
Abstract
Reanimating facial structures following paralysis and muscle loss is a surgical objective that would benefit from improved options for harvesting appropriately sized muscle flaps. The objective of this study is to apply electrohydrodynamic processing to generate a cellularized, elastic, biocomposite scaffold that could develop and mature as muscle in a prepared donor site in vivo, and then be transferred as a thin muscle flap with a vascular and neural pedicle. First, an effective extracellular matrix (ECM) gel type is selected for the biocomposite scaffold from three types of ECM combined with poly(ester urethane)urea microfibers and evaluated in rat abdominal wall defects. Next, two types of precursor cells (muscle-derived and adipose-derived) are compared in constructs placed in rat hind limb defects for muscle regeneration capacity. Finally, with a construct made from dermal ECM and muscle-derived stem cells, protoflaps are implanted in one hindlimb for development and then microsurgically transferred as a free flap to the contralateral limb where stimulated muscle function is confirmed. This construct generation and in vivo incubation procedure may allow the generation of small-scale muscle flaps appropriate for transfer to the face, offering a new strategy for facial reanimation.
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Affiliation(s)
- Hideyoshi Sato
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Dr., Pittsburgh, PA, 15219, USA
| | - Keishi Kohyama
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Dr., Pittsburgh, PA, 15219, USA
| | - Takafumi Uchibori
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Dr., Pittsburgh, PA, 15219, USA
| | - Keisuke Takanari
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Dr., Pittsburgh, PA, 15219, USA
| | - Johnny Huard
- Center for Regenerative Sports Medicine, Steadman Philippon Research Institute, 181 West Meadow Dr., Vail, CO, 81657, USA
| | - Stephen F Badylak
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Dr., Pittsburgh, PA, 15219, USA
- Department of Surgery, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA, 15213, USA
- Department of Bioengineering, University of Pittsburgh, 3700 O'Hara Street, Benedum Hall of Engineering, Pittsburgh, PA, 15261, USA
| | - Antonio D'Amore
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Dr., Pittsburgh, PA, 15219, USA
- Department of Surgery, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA, 15213, USA
- Department of Bioengineering, University of Pittsburgh, 3700 O'Hara Street, Benedum Hall of Engineering, Pittsburgh, PA, 15261, USA
- Fondazione Ri.MED, Palermo, 90133, Italy
| | - William R Wagner
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Dr., Pittsburgh, PA, 15219, USA
- Department of Surgery, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA, 15213, USA
- Department of Bioengineering, University of Pittsburgh, 3700 O'Hara Street, Benedum Hall of Engineering, Pittsburgh, PA, 15261, USA
- Department of Chemical Engineering, University of Pittsburgh, 3700 O'Hara Street, Benedum Hall of Engineering, Pittsburgh, PA, 15261, USA
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5
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Ngo TB, Josyula A, DeStefano S, Fertil D, Faust M, Lokwani R, Sadtler K. Ectopic adipogenesis in response to injury and material implantation in an autoimmune mouse model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.05.561105. [PMID: 37986843 PMCID: PMC10659416 DOI: 10.1101/2023.10.05.561105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Due to the limited capacity of mammals to regenerate complex tissues, researchers have worked to understand the mechanisms of tissue regeneration in organisms that maintain that capacity. One example is the MRL/MpJ mouse strain with unique regenerative capacity in ear pinnae that is absent from other strains, such as the common C57BL/6 strain. The MRL/MpJ mouse has also been associated with an autoimmune phenotype even in the absence of the mutant Fas gene described in its parent strain MRL/lpr. Due to these findings, we evaluated the differences between the responses of MRL/MpJ versus C57BL/6 strain in traumatic muscle injury and subsequent material implantation. One salient feature of the MRL/MpJ response to injury was a robust adipogenesis within the muscle. This was associated with a decrease in M2-like polarization in response to biologically derived extracellular matrix scaffolds. In pro-fibrotic materials, such as polyethylene, there were fewer foreign body giant cells in the MRL/MpJ mice. As there are reports of both positive and negative influences of adipose tissue and adipogenesis on wound healing, this model could provide an important lens to investigate the interplay between stem cells, adipose tissue, and immune responses in trauma and materials implantation.
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Affiliation(s)
- Tran B. Ngo
- Section on Immunoengineering, Center for Biomedical Engineering and Technology Acceleration, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda MD 20814
| | - Aditya Josyula
- Section on Immunoengineering, Center for Biomedical Engineering and Technology Acceleration, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda MD 20814
| | - Sabrina DeStefano
- Section on Immunoengineering, Center for Biomedical Engineering and Technology Acceleration, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda MD 20814
| | - Daphna Fertil
- Section on Immunoengineering, Center for Biomedical Engineering and Technology Acceleration, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda MD 20814
| | - Mondreakest Faust
- Section on Immunoengineering, Center for Biomedical Engineering and Technology Acceleration, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda MD 20814
| | - Ravi Lokwani
- Section on Immunoengineering, Center for Biomedical Engineering and Technology Acceleration, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda MD 20814
| | - Kaitlyn Sadtler
- Section on Immunoengineering, Center for Biomedical Engineering and Technology Acceleration, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda MD 20814
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6
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The War after War: Volumetric Muscle Loss Incidence, Implication, Current Therapies and Emerging Reconstructive Strategies, a Comprehensive Review. Biomedicines 2021; 9:biomedicines9050564. [PMID: 34069964 PMCID: PMC8157822 DOI: 10.3390/biomedicines9050564] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 04/30/2021] [Accepted: 05/14/2021] [Indexed: 11/25/2022] Open
Abstract
Volumetric muscle loss (VML) is the massive wasting of skeletal muscle tissue due to traumatic events or surgical ablation. This pathological condition exceeds the physiological healing process carried out by the muscle itself, which owns remarkable capacity to restore damages but only when limited in dimensions. Upon VML occurring, the affected area is severely compromised, heavily influencing the affected a person’s quality of life. Overall, this condition is often associated with chronic disability, which makes the return to duty of highly specialized professional figures (e.g., military personnel or athletes) almost impossible. The actual treatment for VML is based on surgical conservative treatment followed by physical exercise; nevertheless, the results, in terms of either lost mass and/or functionality recovery, are still poor. On the other hand, the efforts of the scientific community are focusing on reconstructive therapy aiming at muscular tissue void volume replenishment by exploiting biomimetic matrix or artificial tissue implantation. Reconstructing strategies represent a valid option to build new muscular tissue not only to recover damaged muscles, but also to better socket prosthesis in terms of anchorage surfaces and reinnervation substrates for reconstructed mass.
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Mihaly E, Altamirano DE, Tuffaha S, Grayson W. Engineering skeletal muscle: Building complexity to achieve functionality. Semin Cell Dev Biol 2021; 119:61-69. [PMID: 33994095 DOI: 10.1016/j.semcdb.2021.04.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 04/19/2021] [Indexed: 12/12/2022]
Abstract
Volumetric muscle loss (VML) VML is defined as the loss of a critical mass of skeletal muscle that overwhelms the muscle's natural healing mechanisms, leaving patients with permanent functional deficits and deformity. The treatment of these defects is complex, as skeletal muscle is a composite structure that relies closely on the action of supporting tissues such as tendons, vasculature, nerves, and bone. The gold standard of treatment for VML injuries, an autologous muscle flap transfer, suffers from many shortcomings but nevertheless remains the best clinically available avenue to restore function. This review will consider the use of composite tissue engineered constructs, with multiple components that act together to replicate the function of an intact muscle, as an alternative to autologous muscle flaps. We will discuss recent advances in the field of tissue engineering that enable skeletal muscle constructs to more closely reproduce the functionality of an autologous muscle flap by incorporating vasculature, promoting innervation, and reconstructing the muscle-tendon boundary. Additionally, our understanding of the cellular composition of skeletal muscle has evolved to recognize the importance of a diverse variety of cell types in muscle regeneration, including fibro/adipogenic progenitors and immune cells like macrophages and regulatory T cells. We will address recent advances in our understanding of how these cell types interact with, and can be incorporated into, implanted tissue engineered constructs.
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Affiliation(s)
- Eszter Mihaly
- Translational Tissue Engineering Center, School of Medicine, Johns Hopkins University, Baltimore, MD 21231, USA; Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Dallas E Altamirano
- Translational Tissue Engineering Center, School of Medicine, Johns Hopkins University, Baltimore, MD 21231, USA; Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Sami Tuffaha
- Department of Plastic and Reconstructive Surgery, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA; Curtis National Hand Center, MedStar Union Memorial Hospital, Baltimore, MD 21218, USA
| | - Warren Grayson
- Translational Tissue Engineering Center, School of Medicine, Johns Hopkins University, Baltimore, MD 21231, USA; Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Materials Science & Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD 21218, USA; Department of Chemical & Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD 21218, USA; Institute for NanoBioTechnology (INBT), Johns Hopkins University School of Engineering, Baltimore, MD 21218, USA.
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8
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Sorensen JR, Hoffman DB, Corona BT, Greising SM. Secondary denervation is a chronic pathophysiologic sequela of volumetric muscle loss. J Appl Physiol (1985) 2021; 130:1614-1625. [PMID: 33830817 DOI: 10.1152/japplphysiol.00049.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Volumetric muscle loss (VML) is the traumatic loss of muscle tissue that results in long-term functional impairments. Despite the loss of myofibers, there remains an unexplained significant decline in muscle function. VML injury likely extends beyond the defect area, causing negative secondary outcomes to the neuromuscular system, including the neuromuscular junctions (NMJs), yet the extent to which VML induces denervation is unclear. This study systematically examined NMJs surrounding the VML injury, hypothesizing that the sequela of VML includes denervation. The VML injury removed ∼20% of the tibialis anterior (TA) muscle in adult male inbred Lewis rats (n = 43), the noninjured leg served as an intra-animal control. Muscles were harvested up to 48 days post-VML. Synaptic terminals were identified immunohistochemically, and quantitative confocal microscopy evaluated 2,613 individual NMJ. Significant denervation was apparent by 21 and 48 days post-VML. Initially, denervation increased ∼10% within 3 days of injury; with time, denervation further increased to ∼22% and 32% by 21 and 48 days post-VML, respectively, suggesting significant secondary denervation. The appearance of terminal axon sprouting and polyinnervation were observed as early as 7 days post-VML, increasing in number and complexity throughout 48 days. There was no evidence of VML-induced NMJ size alteration, which may be beneficial for interventions aimed at restoring muscle function. This work recognizes VML-induced secondary denervation and poor remodeling of the NMJ as part of the sequela of VML injury; moreover, secondary denervation is a possible contributing factor to the chronic functional impairments and potentially an overlooked treatment target.NEW & NOTEWORTHY This work advances our understanding of the pathophysiologic complexity of volumetric muscle loss injury. Specifically, we identified secondary denervation in the muscle remaining after volumetric muscle loss injuries as a novel aspect of the injury sequela. Denervation increased chronically, in parallel with the appearance of irregular morphological characteristics and destabilization of the neuromuscular junction, which is expected to further confound chronic functional impairments.
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Affiliation(s)
- Jacob R Sorensen
- School of Kinesiology, University of Minnesota, Minneapolis, Minnesota
| | - Daniel B Hoffman
- School of Kinesiology, University of Minnesota, Minneapolis, Minnesota
| | - Benjamin T Corona
- School of Medicine, Wake Forest University, Winston-Salem, North Carolina
| | - Sarah M Greising
- School of Kinesiology, University of Minnesota, Minneapolis, Minnesota
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Dienes J, Browne S, Farjun B, Amaral Passipieri J, Mintz EL, Killian G, Healy KE, Christ GJ. Semisynthetic Hyaluronic Acid-Based Hydrogel Promotes Recovery of the Injured Tibialis Anterior Skeletal Muscle Form and Function. ACS Biomater Sci Eng 2021; 7:1587-1599. [PMID: 33660968 DOI: 10.1021/acsbiomaterials.0c01751] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Volumetric muscle loss (VML) injuries are characterized by a degree of tissue loss that exceeds the endogenous regenerative capacity of muscle, resulting in permanent structural and functional deficits. Such injuries are a consequence of trauma, as well as a host of congenital and acquired diseases and disorders. Despite significant preclinical research with diverse biomaterials, as well as early clinical studies with implantation of decellularized extracellular matrices, there are still significant barriers to more complete restoration of muscle form and function following repair of VML injuries. In fact, identification of novel biomaterials with more advantageous regenerative profiles is a critical limitation to the development of improved therapeutics. As a first step in this direction, we evaluated a novel semisynthetic hyaluronic acid-based (HyA) hydrogel that embodies material features more favorable for robust muscle regeneration. This HyA-based hydrogel is composed of an acrylate-modified HyA (AcHyA) macromer, an AcHyA macromer conjugated with the bsp-RGD(15) peptide sequence to enhance cell adhesion, a high-molecular-weight heparin to sequester growth factors, and a matrix metalloproteinase-cleavable cross-linker to allow for cell-dependent remodeling. In a well-established, clinically relevant rat tibialis anterior VML injury model, we report observations of robust functional recovery, accompanied by volume reconstitution, muscle regeneration, and native-like vascularization following implantation of the HyA-based hydrogel at the site of injury. These findings have important implications for the development and clinical application of the improved biomaterials that will be required for stable and complete functional recovery from diverse VML injuries.
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Affiliation(s)
- Jack Dienes
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Shane Browne
- Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States.,Department of Material Science and Engineering, University of California, Berkeley, Berkeley 94720, United States
| | - Bruna Farjun
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Juliana Amaral Passipieri
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Ellen L Mintz
- Pathology Department, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Grant Killian
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Kevin E Healy
- Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States.,Department of Material Science and Engineering, University of California, Berkeley, Berkeley 94720, United States
| | - George J Christ
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States.,Department of Orthopaedic Surgery, University of Virginia, Charlottesville, Virginia 22908, United States
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10
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3D Printing Decellularized Extracellular Matrix to Design Biomimetic Scaffolds for Skeletal Muscle Tissue Engineering. BIOMED RESEARCH INTERNATIONAL 2020; 2020:2689701. [PMID: 33282941 PMCID: PMC7685790 DOI: 10.1155/2020/2689701] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/08/2020] [Accepted: 10/27/2020] [Indexed: 02/06/2023]
Abstract
Functional engineered muscles are still a critical clinical issue to be addressed, although different strategies have been considered so far for the treatment of severe muscular injuries. Indeed, the regenerative capacity of skeletal muscle (SM) results inadequate for large-scale defects, and currently, SM reconstruction remains a complex and unsolved task. For this aim, tissue engineered muscles should provide a proper biomimetic extracellular matrix (ECM) alternative, characterized by an aligned/microtopographical structure and a myogenic microenvironment, in order to promote muscle regeneration. As a consequence, both materials and fabrication techniques play a key role to plan an effective therapeutic approach. Tissue-specific decellularized ECM (dECM) seems to be one of the most promising material to support muscle regeneration and repair. 3D printing technologies, on the other side, enable the fabrication of scaffolds with a fine and detailed microarchitecture and patient-specific implants with high structural complexity. To identify innovative biomimetic solutions to develop engineered muscular constructs for the treatment of SM loss, the more recent (last 5 years) reports focused on SM dECM-based scaffolds and 3D printing technologies for SM regeneration are herein reviewed. Possible design inputs for 3D printed SM dECM-based scaffolds for muscular regeneration are also suggested.
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11
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Skeletal Muscle Tissue Engineering: Biomaterials-Based Strategies for the Treatment of Volumetric Muscle Loss. Bioengineering (Basel) 2020; 7:bioengineering7030085. [PMID: 32751847 PMCID: PMC7552659 DOI: 10.3390/bioengineering7030085] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/17/2020] [Accepted: 07/28/2020] [Indexed: 12/13/2022] Open
Abstract
Millions of Americans suffer from skeletal muscle injuries annually that can result in volumetric muscle loss (VML), where extensive musculoskeletal damage and tissue loss result in permanent functional deficits. In the case of small-scale injury skeletal muscle is capable of endogenous regeneration through activation of resident satellite cells (SCs). However, this is greatly reduced in VML injuries, which remove native biophysical and biochemical signaling cues and hinder the damaged tissue's ability to direct regeneration. The current clinical treatment for VML is autologous tissue transfer, but graft failure and scar tissue formation leave patients with limited functional recovery. Tissue engineering of instructive biomaterial scaffolds offers a promising approach for treating VML injuries. Herein, we review the strategic engineering of biophysical and biochemical cues in current scaffold designs that aid in restoring function to these preclinical VML injuries. We also discuss the successes and limitations of the three main biomaterial-based strategies to treat VML injuries: acellular scaffolds, cell-delivery scaffolds, and in vitro tissue engineered constructs. Finally, we examine several innovative approaches to enhancing the design of the next generation of engineered scaffolds to improve the functional regeneration of skeletal muscle following VML injuries.
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Bour RK, Sharma PR, Turner JS, Hess WE, Mintz EL, Latvis CR, Shepherd BR, Presnell SC, McConnell MJ, Highley C, Peirce SM, Christ GJ. Bioprinting on sheet-based scaffolds applied to the creation of implantable tissue-engineered constructs with potentially diverse clinical applications: Tissue-Engineered Muscle Repair (TEMR) as a representative testbed. Connect Tissue Res 2020; 61:216-228. [PMID: 31899969 DOI: 10.1080/03008207.2019.1679800] [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] [Indexed: 02/03/2023]
Abstract
Purpose: This report explores the overlooked potential of bioprinting to automate biomanufacturing of simple tissue structures, such as the uniform deposition of (mono)layers of progenitor cells on sheetlike decellularized extracellular matrices (dECM). In this scenario, dECM serves as a biodegradable celldelivery matrix to provide enhanced regenerative microenvironments for tissue repair. The Tissue-Engineered Muscle Repair (TEMR) technology-where muscle progenitor cells are seeded onto a porcine bladder acellular matrix (BAM), serves as a representative testbed for bioprinting applications. Previous work demonstrated that TEMR implantation improved functional outcomes following VML injury in biologically relevant rodent models.Materials and Methods: In the described bioprinting system, a cell-laden hydrogel bioink is used to deposit high cell densities (1.4 × 105-3.5 × 105 cells/cm2), onto both sides of the bladder acellular matrix as proof-of-concept.Results: These bioprinting methods achieve a reproducible and homogeneous distribution of cells, on both sides of the BAM scaffold, after just 24hrs, with cell viability as high as 98%. These preliminary results suggest bioprinting allows for improved dual-sided cell coverage compared to manual-seeding.Conclusions: Bioprinting can enable automated fabrication of TEMR constructs with high fidelity and scalability, while reducing biomanufacturing costs and timelines. Such bioprinting applications are underappreciated, yet critical, to expand the overall biomanufacturing paradigm for tissue engineered medical products. In addition, biofabrication of sheet-like implantable constructs, with cells deposited on both sides, is a process that is both scaffold and cell-type agnostic, and furthermore, is amenable to many geometries, and thus, additional tissue engineering applications beyond skeletal muscle.
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Affiliation(s)
- R K Bour
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - P R Sharma
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - J S Turner
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - W E Hess
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - E L Mintz
- Department of Pathology, University of Virginia, Charlottesville, VA, USA
| | - C R Latvis
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | | | | | - M J McConnell
- Departments of Biochemistry and Molecular Genetics, and Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - C Highley
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA.,Department of Chemical Engineering, University of Virginia, Charlottesville, VA, USA
| | - S M Peirce
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA.,Department of Plastic Surgery, University of Virginia, Charlottesville, VA, USA
| | - G J Christ
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA.,Department of Orthopaedic Surgery, University of Virginia, Charlottesville, VA, USA
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Mintz EL, Passipieri JA, Franklin IR, Toscano VM, Afferton EC, Sharma PR, Christ GJ. Long-Term Evaluation of Functional Outcomes Following Rat Volumetric Muscle Loss Injury and Repair. Tissue Eng Part A 2020; 26:140-156. [PMID: 31578935 DOI: 10.1089/ten.tea.2019.0126] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Volumetric muscle loss (VML) injuries, by definition, exceed the endogenous repair capacity of skeletal muscle resulting in permanent structural and functional deficits. VML injuries present a significant burden for both civilian and military medicine. Despite progress, there is still considerable room for therapeutic improvement. In this regard, tissue-engineered constructs show promise for VML repair, as they provide an opportunity to introduce both scaffolding and cellular components. We have pioneered the development of a tissue-engineered muscle repair (TEMR) technology created by seeding muscle progenitor cells onto a porcine-derived bladder acellular matrix followed by cyclic stretch preconditioning before implantation. Our work to date has demonstrated significant functional repair (60-90% functional recovery) in progressively larger rodent models of VML injury following TEMR implantation. Notwithstanding this success, TEMR implantation in cylindrically shaped VML injuries in the tibialis anterior (TA) muscle was associated with more variable functional outcomes than has been observed in sheet-like muscles such as the latissimus dorsi. In fact, previous observations documented a dichotomy of responses following TEMR implantation in a rodent TA VML injury model; with an ≈61% functional improvement observed in fewer than half (46%) of TEMR-implanted animals at 12 weeks postinjury. This current study builds directly from those observations as we modified the geometry of both the VML injury and the TEMR construct to determine if improved matching of the implanted TEMR construct to the surgically created VML injury resulted in increased functional recovery posttreatment. Following these modifications, we observed a comparable degree of functional improvement in a larger proportion of animals (≈67%) that was durable up to 24 weeks post-TEMR implantation. Moreover, in ≈25% of all TEMR-implanted animals, functional recovery was virtually complete (TEMR max responders), and furthermore, the functional recovery in all 67% of responding animals was accompanied by the presence of native-like muscle properties within the repaired TA muscle, including fiber cross-sectional area, fiber type, vascularization, and innervation. This study emphasizes the importance of tuning the application of tissue engineering technology platforms to the specific requirements of diverse VML injuries to improve functional outcomes. Impact Statement This report confirms and extends previous observations with our implantable tissue-engineered technology platform for repair of volumetric muscle loss (VML) injuries. Based on our prior work, we addressed factors hypothesized to be responsible for significant outcome variability following treatment of VML injuries in a rat tibialis anterior model. Through customization of the muscle repair technology to a specific VML injury, we were able to significantly increase the frequency at which functional recovery occurred, and furthermore, demonstrate durability out to 6 months. In addition, the enhanced biomimetic qualities of repaired muscle tissue were associated with the most robust functional outcomes.
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Affiliation(s)
- Ellen L Mintz
- Department of Pathology, University of Virginia, Charlottesville, Virginia
| | - Juliana A Passipieri
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | | | - Victoria M Toscano
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Emma C Afferton
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Poonam R Sharma
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - George J Christ
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia.,Department of Orthopaedics, University of Virginia, Charlottesville, Virginia
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14
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Gilbert-Honick J, Grayson W. Vascularized and Innervated Skeletal Muscle Tissue Engineering. Adv Healthc Mater 2020; 9:e1900626. [PMID: 31622051 PMCID: PMC6986325 DOI: 10.1002/adhm.201900626] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 09/27/2019] [Indexed: 12/12/2022]
Abstract
Volumetric muscle loss (VML) is a devastating loss of muscle tissue that overwhelms the native regenerative properties of skeletal muscle and results in lifelong functional deficits. There are currently no treatments for VML that fully recover the lost muscle tissue and function. Tissue engineering presents a promising solution for VML treatment and significant research has been performed using tissue engineered muscle constructs in preclinical models of VML with a broad range of defect locations and sizes, tissue engineered construct characteristics, and outcome measures. Due to the complex vascular and neural anatomy within skeletal muscle, regeneration of functional vasculature and nerves is vital for muscle recovery following VML injuries. This review aims to summarize the current state of the field of skeletal muscle tissue engineering using 3D constructs for VML treatment with a focus on studies that have promoted vascular and neural regeneration within the muscle tissue post-VML.
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Affiliation(s)
- Jordana Gilbert-Honick
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Warren Grayson
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Material Sciences & Engineering, Johns Hopkins University, School of Engineering, Baltimore, MD 21218, USA
- Institute for NanoBioTechnology (INBT), Johns Hopkins University School of Engineering, Baltimore, MD 21218, USA
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15
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Passipieri JA, Hu X, Mintz E, Dienes J, Baker HB, Wallace CH, Blemker SS, Christ GJ. In Silico and In Vivo Studies Detect Functional Repair Mechanisms in a Volumetric Muscle Loss Injury. Tissue Eng Part A 2019; 25:1272-1288. [PMID: 30882277 PMCID: PMC6760186 DOI: 10.1089/ten.tea.2018.0280] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 12/10/2018] [Indexed: 11/12/2022] Open
Abstract
IMPACT STATEMENT Despite medical advances, volumetric muscle loss (VML) injuries to craniofacial muscles represent an unmet clinical need. We report an implantable tissue-engineered construct that leads to substantial tissue regeneration and functional recovery in a preclinical model of VML injury that is dimensionally relevant to unilateral cleft lip repair, and a series of corresponding computational models that provide biomechanical insight into mechanism(s) responsible for the VML-induced functional deficits and recovery following tissue-engineered muscle repair implantation. This unique combined approach represents a critical first step toward establishing a crucial biomechanical basis for the development of efficacious regenerative technologies, considering the spectrum of VML injuries.
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Affiliation(s)
- Juliana A. Passipieri
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Xiao Hu
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Ellen Mintz
- Department of Pathology, University of Virginia, Charlottesville, Virginia
| | - Jack Dienes
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Hannah B. Baker
- Wake Forest Institute for Regenerative Medicine, Wake Forest University, Winston-Salem, North Carolina
| | - C. Hunter Wallace
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Silvia S. Blemker
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
- Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia
- Department of Orthopaedic Surgery, University of Virginia, Charlottesville, Virginia
| | - George J. Christ
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
- Department of Orthopaedics, University of Virginia, Charlottesville, Virginia
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16
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Acellular Biologic Scaffolds in Regenerative Medicine: Unacceptable Variability with Acceptable Results. REGENERATIVE ENGINEERING AND TRANSLATIONAL MEDICINE 2019. [DOI: 10.1007/s40883-019-00106-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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17
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Von den Hoff JW, Carvajal Monroy PL, Ongkosuwito EM, van Kuppevelt TH, Daamen WF. Muscle fibrosis in the soft palate: Delivery of cells, growth factors and anti-fibrotics. Adv Drug Deliv Rev 2019; 146:60-76. [PMID: 30107211 DOI: 10.1016/j.addr.2018.08.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/29/2018] [Accepted: 08/06/2018] [Indexed: 02/07/2023]
Abstract
The healing of skeletal muscle injuries after major trauma or surgical reconstruction is often complicated by the development of fibrosis leading to impaired function. Research in the field of muscle regeneration is mainly focused on the restoration of muscle mass while far less attention is paid to the prevention of fibrosis. In this review, we take as an example the reconstruction of the muscles in the soft palate of cleft palate patients. After surgical closure of the soft palate, muscle function during speech is often impaired by a shortage of muscle tissue as well as the development of fibrosis. We will give a short overview of the most common approaches to generate muscle mass and then focus on strategies to prevent fibrosis. These include anti-fibrotic strategies that have been developed for muscle and other organs by the delivery of small molecules, decorin and miRNAs. Anti-fibrotic compounds should be delivered in aligned constructs in order to obtain the organized architecture of muscle tissue. The available techniques for the preparation of aligned muscle constructs will be discussed. The combination of approaches to generate muscle mass with anti-fibrotic components in an aligned muscle construct may greatly improve the functional outcome of regenerative therapies for muscle injuries.
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Affiliation(s)
- Johannes W Von den Hoff
- Department of Orthodontics and Craniofacial Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500HB Nijmegen, The Netherlands.
| | - Paola L Carvajal Monroy
- Department of Oral and Maxillofacial Surgery, Special Dental Care and Orthodontics, Erasmus Medical Center, P.O. Box 2060, 3000CB Rotterdam, The Netherlands.
| | - Edwin M Ongkosuwito
- Department of Orthodontics and Craniofacial Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500HB Nijmegen, The Netherlands.
| | - Toin H van Kuppevelt
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500HB Nijmegen, The Netherlands.
| | - Willeke F Daamen
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500HB Nijmegen, The Netherlands.
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18
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Choi YJ, Jun YJ, Kim DY, Yi HG, Chae SH, Kang J, Lee J, Gao G, Kong JS, Jang J, Chung WK, Rhie JW, Cho DW. A 3D cell printed muscle construct with tissue-derived bioink for the treatment of volumetric muscle loss. Biomaterials 2019; 206:160-169. [PMID: 30939408 DOI: 10.1016/j.biomaterials.2019.03.036] [Citation(s) in RCA: 172] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 02/02/2019] [Accepted: 03/23/2019] [Indexed: 12/21/2022]
Abstract
Volumetric muscle loss (VML) is an irrecoverable injury associated with muscle loss greater than 20%. Although hydrogel-based 3D engineered muscles and the decellularized extracellular matrix (dECM) have been considered for VML treatment, they have shown limited efficacy. We established a novel VML treatment with dECM bioink using 3D cell printing technology. Volumetric muscle constructs composed of cell-laden dECM bioinks were generated with a granule-based printing reservoir. The 3D cell printed muscle constructs exhibited high cell viability without generating hypoxia and enhanced de novo muscle formation in a VML rat model. To improve functional recovery, prevascularized muscle constructs that mimic the hierarchical architecture of vascularized muscles were fabricated through coaxial nozzle printing with muscle and vascular dECM bioinks. Spatially printing tissue-specific dECM bioinks offers organized microenvironmental cues for the differentiation of each cell and improves vascularization, innervation, and functional recovery. Our present results suggest that a 3D cell printing and tissue-derived bioink-based approach could effectively generate biomimetic engineered muscles to improve the treatment of VML injuries.
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Affiliation(s)
- Yeong-Jin Choi
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk, 37673, South Korea; Materials Processing Innovation Research Division, Department of Advanced Biomaterials Research, Korea Institute of Materials Science (KIMS). 797 Changwon-daero, Seongsan-gu, Changwon-si, Gyeongsangnam-do, 51508, South Korea
| | - Young-Joon Jun
- Department of Plastic Surgery, The Catholic University of Korea, 222 Banpodaero, Seocho-gu, Seoul 06591, South Korea
| | - Dong Yeon Kim
- Department of Plastic Surgery, The Catholic University of Korea, 222 Banpodaero, Seocho-gu, Seoul 06591, South Korea
| | - Hee-Gyeong Yi
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk, 37673, South Korea
| | - Su-Hun Chae
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk, 37673, South Korea
| | - Junsu Kang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk, 37673, South Korea
| | - Juyong Lee
- Department of Computer Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk, 37673, South Korea
| | - Ge Gao
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk, 37673, South Korea
| | - Jeong-Sik Kong
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk, 37673, South Korea
| | - Jinah Jang
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk, 37673, South Korea; Department of Creative IT Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk, 37673, South Korea
| | - Wan Kyun Chung
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk, 37673, South Korea
| | - Jong-Won Rhie
- Department of Plastic Surgery, The Catholic University of Korea, 222 Banpodaero, Seocho-gu, Seoul 06591, South Korea.
| | - Dong-Woo Cho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk, 37673, South Korea.
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Anderson SE, Han WM, Srinivasa V, Mohiuddin M, Ruehle MA, Moon JY, Shin E, San Emeterio CL, Ogle ME, Botchwey EA, Willett NJ, Jang YC. Determination of a Critical Size Threshold for Volumetric Muscle Loss in the Mouse Quadriceps. Tissue Eng Part C Methods 2019; 25:59-70. [PMID: 30648479 PMCID: PMC6389771 DOI: 10.1089/ten.tec.2018.0324] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/02/2019] [Indexed: 12/15/2022] Open
Abstract
IMPACT STATEMENT The goal of this study was to determine the threshold for a critically sized, nonhealing muscle defect by characterizing key components in the balance between fibrosis and regeneration as a function of injury size in the mouse quadriceps. There is currently limited understanding of what leads to a critically sized muscle defect and which muscle regenerative components are functionally impaired. With the substantial increase in preclinical VML models as testbeds for tissue engineering therapeutics, defining the critical threshold for VML injuries will be instrumental in characterizing therapeutic efficacy and potential for subsequent translation.
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Affiliation(s)
- Shannon E. Anderson
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory Unversity, Atlanta, Georgia
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
| | - Woojin M. Han
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia
| | - Vunya Srinivasa
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | - Mahir Mohiuddin
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory Unversity, Atlanta, Georgia
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
| | - Marissa A. Ruehle
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory Unversity, Atlanta, Georgia
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
| | - June Young Moon
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | - Eunjung Shin
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | - Cheryl L. San Emeterio
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory Unversity, Atlanta, Georgia
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
| | - Molly E. Ogle
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory Unversity, Atlanta, Georgia
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
| | - Edward A. Botchwey
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory Unversity, Atlanta, Georgia
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
| | - Nick J. Willett
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory Unversity, Atlanta, Georgia
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
- Department of Orthopedics, Emory University, Atlanta, Georgia
- Atlanta Veteran's Affairs Medical Center, Decatur, Georgia
| | - Young C. Jang
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory Unversity, Atlanta, Georgia
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
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20
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Edgar L, Altamimi A, García Sánchez M, Tamburrinia R, Asthana A, Gazia C, Orlando G. Utility of extracellular matrix powders in tissue engineering. Organogenesis 2018; 14:172-186. [PMID: 30183489 PMCID: PMC6300104 DOI: 10.1080/15476278.2018.1503771] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Extracellular matrix (ECM) materials have had remarkable success as scaffolds in tissue engineering (TE) and as therapies for tissue injury whereby the ECM microenvironment promotes constructive remodeling and tissue regeneration. ECM powder and solubilized derivatives thereof have novel applications in TE and RM afforded by the capacity of these constructs to be dynamically modulated. The powder form allows for effective incorporation and penetration of reagents; hence, ECM powder is an efficacious platform for 3D cell culture and vehicle for small molecule delivery. ECM powder offers minimally invasive therapy for tissue injury and successfully treatment for wounds refractory to first-line therapies. Comminution of ECM and fabrication of powder-derived constructs, however, may compromise the biological integrity of the ECM. The current lack of optimized fabrication protocols prevents a more extensive and effective clinical application of ECM powders. Further study on methods of ECM powder fabrication and modification is needed.
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Affiliation(s)
- Lauren Edgar
- Wake Forest School of Medicine, Department of Surgery, Winston-Salem, NC, USA,Correspondence to: Lauren Elizabeth Edgar, E-mail:
| | - Afnan Altamimi
- Wake Forest Institute for Regenerative Medicine, Department of Surgery, Winston-Salem, NC, USA,King Khalid University Hospital, Department of Surgery, Riyadh, Saudi Arabia
| | | | - Riccardo Tamburrinia
- Wake Forest School of Medicine, Department of Surgery, Winston-Salem, NC, USA,Wake Forest Institute for Regenerative Medicine, Department of Surgery, Winston-Salem, NC, USA,School of Experimental Medicine, University of Pavia, Pavia, Italy
| | - Amish Asthana
- Wake Forest Institute for Regenerative Medicine, Department of Surgery, Winston-Salem, NC, USA
| | - Carlo Gazia
- Wake Forest Institute for Regenerative Medicine, Department of Surgery, Winston-Salem, NC, USA
| | - Giuseppe Orlando
- Wake Forest School of Medicine, Department of Surgery, Winston-Salem, NC, USA,Wake Forest Institute for Regenerative Medicine, Department of Surgery, Winston-Salem, NC, USA
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21
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Dziki JL, Badylak SF. Extracellular Matrix for Myocardial Repair. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1098:151-171. [PMID: 30238370 DOI: 10.1007/978-3-319-97421-7_8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Multiple strategies have been investigated to restore functional myocardium following injury or disease including the local administration of cytokines or chemokines, stem/progenitor cell therapy, mechanical circulatory support, pharmacologic use, and the use of inductive biomaterials. The use of xenogeneic biologic scaffolds composed of extracellular matrix (ECM) has been shown to facilitate functional restoration of several tissues and organs including the esophagus, skeletal muscle, skin, and myocardium, among others. The present chapter describes the current understanding of specific components of biologic scaffolds composed of ECM, the mechanisms by which ECM bioscaffolds promote constructive cardiac remodeling after injury, determinants of remodeling outcome, and the versatility of ECM as a potential cardiac therapeutic.
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Affiliation(s)
- Jenna L Dziki
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Stephen F Badylak
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA. .,Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. .,Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
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22
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Abstract
Volumetric muscle loss (VML) resulting from extremity trauma presents chronic and persistent functional deficits which ultimately manifest disability. Acellular biological scaffolds, or decellularized extracellular matrices (ECMs), embody an ideal treatment platform due to their current clinical use for soft tissue repair, off-the-shelf availability, and zero autogenous donor tissue burden. ECMs have been reported to promote functional skeletal muscle tissue remodeling in small and large animal models of VML injury, and this conclusion was reached in a recent clinical trial that enrolled 13 patients. However, numerous other pre-clinical reports have not observed ECM-mediated skeletal muscle regeneration. The current study was designed to reconcile these discrepancies. The capacity of ECMs to orchestrate functional muscle tissue remodeling was interrogated in a porcine VML injury model using unbiased assessments of muscle tissue regeneration and functional recovery. Here, we show that VML injury incites an overwhelming inflammatory and fibrotic response that leads to expansive fibrous tissue deposition and chronic functional deficits, which ECM repair does not augment.
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Decellularized extracellular matrix repair of volumetric muscle loss injury impairs adjacent bone healing in a rat model of complex musculoskeletal trauma. J Trauma Acute Care Surg 2017; 81:S184-S190. [PMID: 27533905 DOI: 10.1097/ta.0000000000001212] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Traumatic muscle loss (i.e., volumetric muscle loss [VML] injury) impairs adjacent fracture healing but is often left untreated. A promising therapy for this application is a decellularized extracellular matrix (ECM) because of their capacity to regenerate a vascularized tissue bed. This study tested the hypothesis that repair of VML concomitant to fracture with a small intestine submucosa (SIS)-ECM improves musculoskeletal healing. METHODS In male Lewis rats (~375 g), a 3-mm segmental bone defect (SBD) was created in concomitance with a 6-mm, full-thickness VML injury to the adjacent tibialis anterior (TA) muscle. For all rats (n = 10), the SBD was treated with internal plate fixation and delivery of recombinant human bone morphogenetic protein 2 (1 μg) on a collagen sponge. The VML either had no repair or SIS-ECM repair (n = 5/group). Bone regeneration within the SBD (BV/TV [bone volume as a fraction of total volume]) was assessed via in vivo micro-computed tomography at 2, 4, and 6 weeks and histology at 6 weeks after injury. Tibialis anterior muscle in vivo strength and histologic assessments were performed at 6 weeks after injury. RESULTS Compared with no repair, SIS-ECM presented -21% (p = 0.09) and -27% (p = 0.004) BV/TV at 4 and 6 weeks after injury, respectively. At 6 weeks, the SBD gap length was shorter for the no repair than that for the SIS-ECM (2.64 ± 0.30 and 3.67 ± 0.41 mm, respectively; p = 0.09), whereas the distances from the end of each cortical segment to the center of the first stabilization screw were longer (1.86 ± 0.25 and 0.85 ± 0.30 mm, respectively; p = 0.035), indicating enhanced resorption in the SIS-ECM group. Both groups presented similar magnitude TA muscle strength deficits compared with their contralateral limbs (10-150 Hz: no repair, -58% to 67%; SIS-ECM, -51% to 74%). The TA muscle of the SIS-ECM group was remarkable for its presentation of fibrosis, edema, and immune cell presence. CONCLUSIONS Small intestine submucosa-ECM VML repair impaired open fracture healing and failed to improve skeletal muscle strength.
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Kelly SH, Shores LS, Votaw NL, Collier JH. Biomaterial strategies for generating therapeutic immune responses. Adv Drug Deliv Rev 2017; 114:3-18. [PMID: 28455189 PMCID: PMC5606982 DOI: 10.1016/j.addr.2017.04.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 04/19/2017] [Accepted: 04/21/2017] [Indexed: 01/04/2023]
Abstract
Biomaterials employed to raise therapeutic immune responses have become a complex and active field. Historically, vaccines have been developed primarily to fight infectious diseases, but recent years have seen the development of immunologically active biomaterials towards an expanding list of non-infectious diseases and conditions including inflammation, autoimmunity, wounds, cancer, and others. This review structures its discussion of these approaches around a progression from single-target strategies to those that engage increasingly complex and multifactorial immune responses. First, the targeting of specific individual cytokines is discussed, both in terms of delivering the cytokines or blocking agents, and in terms of active immunotherapies that raise neutralizing immune responses against such single cytokine targets. Next, non-biological complex drugs such as randomized polyamino acid copolymers are discussed in terms of their ability to raise multiple different therapeutic immune responses, particularly in the context of autoimmunity. Last, biologically derived matrices and materials are discussed in terms of their ability to raise complex immune responses in the context of tissue repair. Collectively, these examples reflect the tremendous diversity of existing approaches and the breadth of opportunities that remain for generating therapeutic immune responses using biomaterials.
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Affiliation(s)
- Sean H Kelly
- Duke University, Department of Biomedical Engineering, United States
| | - Lucas S Shores
- Duke University, Department of Biomedical Engineering, United States
| | - Nicole L Votaw
- Duke University, Department of Biomedical Engineering, United States
| | - Joel H Collier
- Duke University, Department of Biomedical Engineering, United States.
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Christ GJ. Introduction. Cells Tissues Organs 2016; 202:141-142. [PMID: 27825161 DOI: 10.1159/000446975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Corona BT, Greising SM. Challenges to acellular biological scaffold mediated skeletal muscle tissue regeneration. Biomaterials 2016; 104:238-46. [DOI: 10.1016/j.biomaterials.2016.07.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 07/11/2016] [Accepted: 07/16/2016] [Indexed: 02/08/2023]
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Dziki J, Badylak S, Yabroudi M, Sicari B, Ambrosio F, Stearns K, Turner N, Wyse A, Boninger ML, Brown EHP, Rubin JP. An acellular biologic scaffold treatment for volumetric muscle loss: results of a 13-patient cohort study. NPJ Regen Med 2016; 1:16008. [PMID: 29302336 PMCID: PMC5744714 DOI: 10.1038/npjregenmed.2016.8] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 02/08/2016] [Accepted: 03/22/2016] [Indexed: 12/13/2022] Open
Abstract
Volumetric muscle loss (VML) is a severe and debilitating clinical problem. Current standard of care includes physical therapy or orthotics, which do not correct underlying strength deficits, and surgical tendon transfers or muscle transfers, which involve donor site morbidity and fall short of restoring function. The results of a 13-patient cohort study are described herein and involve a regenerative medicine approach for VML treatment. Acellular bioscaffolds composed of mammalian extracellular matrix (ECM) were implanted and combined with aggressive and early physical therapy following treatment. Immunolabeling of ultrasound-guided biopsies, and magnetic resonance imaging and computed tomography imaging were performed to analyse the presence of stem/progenitor cells and formation of new skeletal muscle. Force production, range-of-motion and functional task performance were analysed by physical therapists. Electrodiagnostic evaluation was used to analyse presence of innervated skeletal muscle. This study is registered with ClinicalTrials.gov, numbers NCT01292876. In vivo remodelling of ECM bioscaffolds was associated with mobilisation of perivascular stem cells; formation of new, vascularised, innervated islands of skeletal muscle within the implantation site; increased force production; and improved functional task performance when compared with pre-operative performance. Compared with pre-operative performance, by 6 months after ECM implantation, patients showed an average improvement of 37.3% (P<0.05) in strength and 27.1% improvement in range-of-motion tasks (P<0.05). Implantation of acellular bioscaffolds derived from ECM can improve strength and function, and promotes site-appropriate remodelling of VML defects. These findings provide early evidence of bioscaffolding as a viable treatment of VML.
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Affiliation(s)
- Jenna Dziki
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Stephen Badylak
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mohammad Yabroudi
- Department of Physical Therapy, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Rehabilitation Sciences, Jordan University of Science and Technology, Al Ramtha, Irbid, Jordan
| | - Brian Sicari
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Fabrisia Ambrosio
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Physical Therapy, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kristen Stearns
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Neill Turner
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Aaron Wyse
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael L Boninger
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Elke H P Brown
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - J Peter Rubin
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Plastic Surgery, University of Pittsburgh, Pittsburgh, PA, USA
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