Microvascular transfer of autologous muscle provides an option for facial reanimation in some cases of facial nerve palsy and for the treatment of certain craniofacial muscle defects.
The functional outcome of the procedure depends upon adequate reinnervation of the grafted muscle, which presents considerable challenges. A recent article by Riamondo et al.sought to promote functional innervation through injection of alginate hydrogels into the grafted tissue as vehicles for controlled local delivery of vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1) in rat and rabbit models. The authors demonstrated improved functional innervation outcomes in a murine model of sciatic nerve ligation in both young and aged mice. The authors then translated the approach to a rabbit model of craniofacial gracilis muscle transplantation, in which they found improved muscle innervation and functional improvement with growth factor delivery. Administration of booster injections of the biomaterials releasing the growth factors prolonged the functional recovery. Overall, the article demonstrates the efficacy of noninvasive administration of biomaterials for local delivery of biologically active factors to promote reinnervation and functional recovery upon muscle grafting in a craniofacial site. While the approach presents clear implications for autologous muscle transfer procedures, the approach may also facilitate successful innervation and function of tissue engineered muscle grafts as they emerge in the craniofacial space.
Combined delivery of VEGF and IGF-1 promotes functional innervation in mice and improves muscle transplantation in rabbits.
Raimondo TM, Li H, Kwee BJ, Kinsley S, Budina E, Anderson EM, Doherty EJ, Talbot SG, Mooney DJ. Biomaterials. 2019;216:119246.