title: Neurotization improves contractile forces of tissue-engineered skeletal muscle.
abstract: Engineered functional skeletal muscle would be beneficial in reconstructive surgery. Our previous work successfully generated 3-dimensional vascularized skeletal muscle in vivo. Because neural signals direct muscle maturation, we hypothesized that neurotization of these constructs would increase their contractile force. Additionally, should neuromuscular junctions (NMJs) develop, indirect stimulation (via the nerve) would be possible, allowing for directed control. Rat myoblasts were cultured, suspended in fibrin gel, and implanted within silicone chambers around the femoral vessels and transected femoral nerve of syngeneic rats for 4 weeks. Neurotized constructs generated contractile forces 5 times as high as the non-neurotized controls. Indirect stimulation via the nerve elicited contractions of neurotized constructs. Curare administration ceased contraction in these constructs, providing physiologic evidence of NMJ formation. Histology demonstrated intact muscle fibers, and immunostaining positively identified NMJs. These results indicate that neurotization of engineered skeletal muscle significantly increases force generation and causes NMJs to develop, allowing indirect muscle stimulation.
authors.affiliation: Section of Plastic and Reconstructive Surgery, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Vikas
authors.initials: V
authors.lastname: Dhawan
authors.forename: Ian F
authors.initials: IF
authors.lastname: Lytle
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Dow
authors.forename: Yen-Chih
authors.initials: YC
authors.lastname: Huang
authors.forename: David L
authors.initials: DL
authors.lastname: Brown
mesh_terms: D000818:Animals; D002038:Bungarotoxins / Q000378:metabolism; D002469:Cell Separation; D002478:Cells, Cultured; D002498:Centrifugation; D017364:Collagenases / Q000494:pharmacology; D016895:Culture Media, Serum-Free; D003472:Curare / Q000494:pharmacology; D005263:Femoral Artery / Q000601:surgery; D005267:Femoral Nerve / Q000601:surgery; D005268:Femoral Vein / Q000601:surgery; D005337:Fibrin / Q000737:chemistry; D005374:Filtration; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D005782:Gels / Q000737:chemistry; D007150:Immunohistochemistry; D008954:Models, Biological; D009119:Muscle Contraction / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000166:cytology* / Q000502:physiology*; D009469:Neuromuscular Junction / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology* / Q000502:physiology* / Q000637:transplantation; D013696:Temperature; D013997:Time Factors; D046509:Tissue Culture Techniques; D023822:Tissue Engineering / Q000379:methods*; D014185:Transplantation, Isogeneic