Effect of Local Administration of Verapamil Combined with Chitosan Based Hybrid Nanofiber Conduit on Transected Sciatic Nerve in Rat

OBJECTIVE: To assess the effect of locally administered verapamil on transected peripheral nerve regeneration and functional recovery. METHODS: Sixty male healthy white Wistar rats were divided into four experimental groups (n=15), randomly: In transected group (TC), left sciatic nerve was transected and stumps were fixed in the adjacent muscle. In treatment group defect was bridged using chitosan tube (CHIT/Verapamil) filled with 10 µL verapamil (100ng/mL). In chitosan conduit group (CHIT), the tube was filled with phosphate-buffered saline alone. In sham-operated group (SHAM), sciatic nerve was exposed and manipulated. The repair trend was examined based on behavioral and performance tests as well as the variations of the gastrocnemius muscle, morphometric indices, and immunohistochemical indices. RESULTS: Sciatic nerve functional study, muscle mass and morphometric indices confirmed faster recovery of regenerated axons in CHIT/Verapamil than CHIT group (P = 0.001). When loaded in a chitosan tube verapamil accelerated and improved functional recovery and morphometric indices of sciatic nerve. Immunohistochemical analysis revealed the S-100 protein was vastly present in the transverse nerve sections and the myelin sheath. In the treatment group (chit/verapamil), the immunohistochemical susceptibility of the axons being repaired and the axons in the myelin sheath to S-100 protein was higher than the other groups. CONCLUSION: The present study demonstrated that a single local application of verapamil could accelerate functional recovery after transection of sciatic nerve.