Controlled Release of Nerve Growth Factor and Basic Fibroblast Growth Factor Combined with Small-Gap Anastomosis Enhances Sciatic Nerve Regeneration

Abstract

Objectives Nerve regeneration after peripheral nerve injury is a slow process with a limited degree of functional recovery, resulting in a high disability rate. Thus, accelerating the rate of nerve regeneration and improving the degree of nerve repair is a clinical challenge. This study aimed to investigate the role of growth factor gel combined with small-gap nerve anastomosis in the regeneration of sciatic nerve injury in rats. This was achieved by injecting nerve growth factor (NGF) and basic fibroblast growth factor (bFGF) gel into a silicon chamber that bridged the transection of the nerve. Methods In 27 randomly chosen Sprague Dawley rats, a sharp blade was used to transect the right hind leg sciatic nerve. The rats were divided into 3 groups: in groups A and B, silicon tubes containing NGF and bFGF gel or saline, respectively, were used to bridge the nerve proximal and distal ends (3-mm gap), and in group C, the nerve proximal and distal ends were directly sutured. Eight weeks after surgery, the sciatic nerve function index, neural electrophysiology, and muscle wet weight as well as histological, ultrastructural, and immunohistochemical parameters were evaluated. Results The sciatic nerve function index, nerve conduction velocity, muscle wet weight, density of regenerated nerve fibers, and myelination in group A were better than those in group B or C, but the sciatic nerve function index, muscle wet weight, and thickness of myelination in the 3 groups were not significantly different (P > 0.05). There were no significant differences innerve conduction velocity between groups A and B (P > 0.05), but it was higher in both groups than that of group C (P < 0.05). The regenerated nerve fiber density in the 3 groups showed significant differences (P < 0.05). Conclusions Small-gap nerve anastomosis can provide a good regenerative microenvironment for rat sciatic nerve regeneration, and the combined strategy of growth factor gel with small-gap nerve anastomosis appears to have a superior effect on nerve repair.