title: Improved vascular organization enhances functional integration of engineered skeletal muscle grafts.
abstract: Severe traumatic events such as burns, and cancer therapy, often involve a significant loss of tissue, requiring surgical reconstruction by means of autologous muscle flaps. The scant availability of quality vascularized flaps and donor site morbidity often limit their use. Engineered vascularized grafts provide an alternative for this need. This work describes a first-time analysis, of the degree of in vitro vascularization and tissue organization, required to enhance the pace and efficacy of vascularized muscle graft integration in vivo. While one-day in vitro was sufficient for graft integration, a three-week culturing period, yielding semiorganized vessel structures and muscle fibers, significantly improved grafting efficacy. Implanted vessel networks were gradually replaced by host vessels, coupled with enhanced perfusion and capillary density. Upregulation of key graft angiogenic factors suggest its active role in promoting the angiogenic response. Transition from satellite cells to mature fibers was indicated by increased gene expression, increased capillary to fiber ratio, and similar morphology to normal muscle. We suggest a "relay" approach in which extended in vitro incubation, enabling the formation of a more structured vascular bed, allows for graft-host angiogenic collaboration that promotes anastomosis and vascular integration. The enhanced angiogenic response supports enhanced muscle regeneration, maturation, and integration.
authors: Biomedical Engineering Faculty, Technion-Israel Institute of Technology, Haifa 32000, Israel.
authors: Jacob
authors: J
authors: Koffler
authors: Keren
authors: K
authors: Kaufman-Francis
authors: Yulia
authors: Y
authors: Shandalov
authors: Shandalov
authors: S
authors: Yulia
authors: Dana
authors: D
authors: Egozi
authors: Egozi
authors: E
authors: Dana
authors: Daria Amiad
authors: DA
authors: Pavlov
authors: Amiad Pavlov
authors: AP
authors: Daria
authors: Amir
authors: A
authors: Landesberg
authors: Shulamit
authors: S
authors: Levenberg
mesh_terms: D000818:Animals; D001705:Bioprosthesis; D002460:Cell Line; D051379:Mice; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000166:cytology; D018919:Neovascularization, Physiologic / Q000502:physiology*; D012038:Regeneration / Q000502:physiology*; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology / Q000378:metabolism*; D023822:Tissue Engineering