The Experts below are selected from a list of 5550 Experts worldwide ranked by ideXlab platform
Ioannis V Yannas - One of the best experts on this subject based on the ideXlab platform.
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regeneration of injured skin and peripheral nerves requires control of wound contraction not scar formation
Wound Repair and Regeneration, 2017Co-Authors: Ioannis V Yannas, Dimitrios S Tzeranis, Peter T C SoAbstract:We review the mounting evidence that regeneration is induced in wounds in skin and peripheral nerves by a simple modification of the wound healing process. Here, the process of induced regeneration is compared to the other two well-known processes by which wounds close, i.e., contraction and scar formation. Direct evidence supports the hypothesis that the mechanical force of contraction (planar in skin wounds, circumferential in nerve wounds) is the driver guiding the orientation of assemblies of myofibroblasts (MFB) and collagen fibers during scar formation in untreated wounds. We conclude that scar formation depends critically on wound contraction and is, therefore, a healing process secondary to contraction. Wound contraction and regeneration did not coincide during healing in a number of experimental models of spontaneous (untreated) regeneration described in the literature. Furthermore, in other studies in which an efficient contraction-blocker, a collagen scaffold named dermis regeneration template (DRT), and variants of it, were grafted on skin wounds or peripheral nerve wounds, regeneration was systematically observed in the absence of contraction. We conclude that contraction and regeneration are mutually antagonistic processes. A dramatic change in the phenotype of MFB was observed when the contraction-blocking scaffold DRT was used to treat wounds in skin and peripheral nerves. The phenotype change was directly observed as drastic reduction in MFB density, dispersion of MFB assemblies and loss of alignment of the long MFB axes. These observations were explained by the evidence of a surface-biological interaction of MFB with the scaffold, specifically involving binding of MFB integrins α1β1 and α2β1 to ligands GFOGER and GLOGER naturally present on the surface of the collagen scaffold. In summary, we show that regeneration of wounded skin and peripheral nerves in the Adult Mammal can be induced simply by appropriate control of wound contraction, rather than of scar formation.
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The Irreversibility of Organ Injury
Tissue and Organ Regeneration in Adults, 2014Co-Authors: Ioannis V YannasAbstract:In the Adult Mammal, injury to the stroma is typically irreversible and leads to formation of nonphysiological scar tissue (repair). Every organ in the Adult can be irreversibly injured, resulting in repair with scar formation. In certain organs injury is irreversible when it leads to damage of specific tissues while in others it becomes irreversible when the injury exceeds a critical size.
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common features of optimal collagen scaffolds that disrupt wound contraction and enhance regeneration both in peripheral nerves and in skin
Biomaterials, 2012Co-Authors: Eric C Soller, Peter T C So, Dimitrios S Tzeranis, Ioannis V YannasAbstract:Abstract The Adult Mammal responds to severe injury of most organs spontaneously by wound contraction and scar formation, rather than by regeneration. In severe skin wounds, the ability of porous collagen scaffolds to induce regeneration was found to correlate strongly with a reduction in wound contraction rate. Here, we present quantitative evidence of a similar positive relationship between the extent of disruption of tissue contraction and quality of peripheral nerve regeneration in transected rat peripheral nerves. Our observations suggest that porous collagen scaffolds enhance regeneration both in injured Adult skin and peripheral nerves by disrupting the formation of a contractile cell capsule at the edges of the wound. Preliminary observations made with other injured organs support the hypothesis that capsules or clusters of contractile cells impose a universal mechanical barrier during wound healing which, if disrupted appropriately, enhances the quality of induced regeneration in a wider range of organs.
Peter T C So - One of the best experts on this subject based on the ideXlab platform.
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regeneration of injured skin and peripheral nerves requires control of wound contraction not scar formation
Wound Repair and Regeneration, 2017Co-Authors: Ioannis V Yannas, Dimitrios S Tzeranis, Peter T C SoAbstract:We review the mounting evidence that regeneration is induced in wounds in skin and peripheral nerves by a simple modification of the wound healing process. Here, the process of induced regeneration is compared to the other two well-known processes by which wounds close, i.e., contraction and scar formation. Direct evidence supports the hypothesis that the mechanical force of contraction (planar in skin wounds, circumferential in nerve wounds) is the driver guiding the orientation of assemblies of myofibroblasts (MFB) and collagen fibers during scar formation in untreated wounds. We conclude that scar formation depends critically on wound contraction and is, therefore, a healing process secondary to contraction. Wound contraction and regeneration did not coincide during healing in a number of experimental models of spontaneous (untreated) regeneration described in the literature. Furthermore, in other studies in which an efficient contraction-blocker, a collagen scaffold named dermis regeneration template (DRT), and variants of it, were grafted on skin wounds or peripheral nerve wounds, regeneration was systematically observed in the absence of contraction. We conclude that contraction and regeneration are mutually antagonistic processes. A dramatic change in the phenotype of MFB was observed when the contraction-blocking scaffold DRT was used to treat wounds in skin and peripheral nerves. The phenotype change was directly observed as drastic reduction in MFB density, dispersion of MFB assemblies and loss of alignment of the long MFB axes. These observations were explained by the evidence of a surface-biological interaction of MFB with the scaffold, specifically involving binding of MFB integrins α1β1 and α2β1 to ligands GFOGER and GLOGER naturally present on the surface of the collagen scaffold. In summary, we show that regeneration of wounded skin and peripheral nerves in the Adult Mammal can be induced simply by appropriate control of wound contraction, rather than of scar formation.
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common features of optimal collagen scaffolds that disrupt wound contraction and enhance regeneration both in peripheral nerves and in skin
Biomaterials, 2012Co-Authors: Eric C Soller, Peter T C So, Dimitrios S Tzeranis, Ioannis V YannasAbstract:Abstract The Adult Mammal responds to severe injury of most organs spontaneously by wound contraction and scar formation, rather than by regeneration. In severe skin wounds, the ability of porous collagen scaffolds to induce regeneration was found to correlate strongly with a reduction in wound contraction rate. Here, we present quantitative evidence of a similar positive relationship between the extent of disruption of tissue contraction and quality of peripheral nerve regeneration in transected rat peripheral nerves. Our observations suggest that porous collagen scaffolds enhance regeneration both in injured Adult skin and peripheral nerves by disrupting the formation of a contractile cell capsule at the edges of the wound. Preliminary observations made with other injured organs support the hypothesis that capsules or clusters of contractile cells impose a universal mechanical barrier during wound healing which, if disrupted appropriately, enhances the quality of induced regeneration in a wider range of organs.
Dimitrios S Tzeranis - One of the best experts on this subject based on the ideXlab platform.
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regeneration of injured skin and peripheral nerves requires control of wound contraction not scar formation
Wound Repair and Regeneration, 2017Co-Authors: Ioannis V Yannas, Dimitrios S Tzeranis, Peter T C SoAbstract:We review the mounting evidence that regeneration is induced in wounds in skin and peripheral nerves by a simple modification of the wound healing process. Here, the process of induced regeneration is compared to the other two well-known processes by which wounds close, i.e., contraction and scar formation. Direct evidence supports the hypothesis that the mechanical force of contraction (planar in skin wounds, circumferential in nerve wounds) is the driver guiding the orientation of assemblies of myofibroblasts (MFB) and collagen fibers during scar formation in untreated wounds. We conclude that scar formation depends critically on wound contraction and is, therefore, a healing process secondary to contraction. Wound contraction and regeneration did not coincide during healing in a number of experimental models of spontaneous (untreated) regeneration described in the literature. Furthermore, in other studies in which an efficient contraction-blocker, a collagen scaffold named dermis regeneration template (DRT), and variants of it, were grafted on skin wounds or peripheral nerve wounds, regeneration was systematically observed in the absence of contraction. We conclude that contraction and regeneration are mutually antagonistic processes. A dramatic change in the phenotype of MFB was observed when the contraction-blocking scaffold DRT was used to treat wounds in skin and peripheral nerves. The phenotype change was directly observed as drastic reduction in MFB density, dispersion of MFB assemblies and loss of alignment of the long MFB axes. These observations were explained by the evidence of a surface-biological interaction of MFB with the scaffold, specifically involving binding of MFB integrins α1β1 and α2β1 to ligands GFOGER and GLOGER naturally present on the surface of the collagen scaffold. In summary, we show that regeneration of wounded skin and peripheral nerves in the Adult Mammal can be induced simply by appropriate control of wound contraction, rather than of scar formation.
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common features of optimal collagen scaffolds that disrupt wound contraction and enhance regeneration both in peripheral nerves and in skin
Biomaterials, 2012Co-Authors: Eric C Soller, Peter T C So, Dimitrios S Tzeranis, Ioannis V YannasAbstract:Abstract The Adult Mammal responds to severe injury of most organs spontaneously by wound contraction and scar formation, rather than by regeneration. In severe skin wounds, the ability of porous collagen scaffolds to induce regeneration was found to correlate strongly with a reduction in wound contraction rate. Here, we present quantitative evidence of a similar positive relationship between the extent of disruption of tissue contraction and quality of peripheral nerve regeneration in transected rat peripheral nerves. Our observations suggest that porous collagen scaffolds enhance regeneration both in injured Adult skin and peripheral nerves by disrupting the formation of a contractile cell capsule at the edges of the wound. Preliminary observations made with other injured organs support the hypothesis that capsules or clusters of contractile cells impose a universal mechanical barrier during wound healing which, if disrupted appropriately, enhances the quality of induced regeneration in a wider range of organs.
Bradley B Olwin - One of the best experts on this subject based on the ideXlab platform.
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syndecan 3 and syndecan 4 specifically mark skeletal muscle satellite cells and are implicated in satellite cell maintenance and muscle regeneration
Developmental Biology, 2001Co-Authors: D D W Cornelison, Heather M Stanley, Mark S Filla, Alan C. Rapraeger, Bradley B OlwinAbstract:Myogenesis in the embryo and the Adult Mammal consists of a highly organized and regulated sequence of cellular processes to form or repair muscle tissue that include cell proliferation, migration, and differentiation. Data from cell culture and in vivo experiments implicate both FGFs and HGF as critical regulators of these processes. Both factors require heparan sulfate glycosaminoglycans for signaling from their respective receptors. Since syndecans, a family of cell-surface transmembrane heparan sulfate proteoglycans (HSPGs) are implicated in FGF signaling and skeletal muscle differentiation, we examined the expression of syndecans 1‐ 4 in embryonic, fetal, postnatal, and Adult muscle tissue, as well as on primary Adult muscle fiber cultures. We show that syndecan-1, -3, and -4 are expressed in developing skeletal muscle tissue and that syndecan-3 and -4 expression is highly restricted in Adult skeletal muscle to cells retaining myogenic capacity. These two HSPGs appear to be expressed exclusively and universally on quiescent Adult satellite cells in Adult skeletal muscle tissue, suggesting a role for HSPGs in satellite cell maintenance or activation. Once activated, all satellite cells maintain expression of syndecan-3 and syndecan-4 for at least 96 h, also implicating these HSPGs in muscle regeneration. Inhibition of HSPG sulfation by treatment of intact myofibers with chlorate results in delayed proliferation and altered MyoD expression, demonstrating that heparan sulfate is required for proper progression of the early satellite cell myogenic program. These data suggest that, in addition to providing potentially useful new markers for satellite cells, syndecan-3 and syndecan-4 may play important regulatory roles in satellite cell maintenance, activation, proliferation, and differentiation during skeletal muscle regeneration. © 2001 Academic Press
Charles J. Heckman - One of the best experts on this subject based on the ideXlab platform.
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Enhancement of Bistability in Spinal Motoneurons In Vivo by the Noradrenergic α1 Agonist Methoxamine
Journal of neurophysiology, 1999Co-Authors: Robert H. Lee, Charles J. HeckmanAbstract:Enhancement of bistability in spinal motoneurons in vivo by the noradrenergic α1 agonist methoxamine. Like many types of motoneurons, spinal motoneurons in the Adult Mammal can exhibit bistable beh...
