Innervation of an Engineered Muscle Graft for Reconstruction of Muscle Defects

Autologous muscle flaps are commonly used to reconstruct defects that involve muscle impairment. In order to maintain viability and functionality of these flaps, they must be properly vascularized and innervated. Tissue engineered muscle could potentially replace autologous muscle tissue, but still require establishment of sufficient innervation to ensure functionality. In this study, we explored the possibility of innervating engineered muscle grafts transplanted to an abdominal wall defect in mice, by diverting the native femoral nerve to the graft. Six weeks post-transplantation, nerve conduction studies and electromyography were performed. The electrophysiological tests that were performed demonstrated increased innervation in engineered grafts that were neurotized with the femoral nerve, as compared to non-neurotized grafts. Histological assessments revealed axonal penetration and formation of neuromuscular junctions within the grafts. The innervation process described here promised to advance the fabrication of fully functional engineered muscle grafts that will be of utility in clinical settings.