Functional motor recovery after peripheral nerve repair with an aligned nanofiber tubular conduit in a rat model

Aim: Current synthetic tubular conduits are inferior to nerve autograft for the repair of segmental peripheral nerve injuries. We examined motor outcomes with the use of longitudinally aligned poly (L-lactide-co-caprolactone) nanofiber conduits for repair of nerve gap injury in a rat model. Methods: Ten-millimeter segments of sciatic nerve were resected in 44 Lewis rats. The gaps were either left unrepaired (n = 6), repaired with nerve autograft (n = 19), or repaired with conduit (n = 19). After 12 weeks, nerve conduction latency, compound muscle action potential amplitude, muscle force and muscle mass were measured. The numbers of axons and axon diameters both within the grafts and distally were determined. Results: After 12 weeks, gastrocnemius isometric tetanic force and muscle mass for the conduit group reached 85 and 82% of autograft values, respectively. Nerve conduction and compound muscle action potential were not significantly different between these two groups, although the latter approached significance. There was no recovery in the unrepaired group. Conclusion: Muscle recovery for the animals treated with this aligned nanofiber conduit approached that of autograft, suggesting the importance of internal conduit structure for nerve repair.