Progress in the research and development of nerve conduits

The reconstruction after peripheral nerve damage, especially for long‐segment nerve defects, remains a clinical challenge. Autologous nerve graft transplantation is an efficient method for the repair of peripheral nerve defects, but the involved com‐plications and shortcomings have greatly limited the clinical efficacy of treatments offered to patients with nerve defects. Thus, there is an urgent need to develop new therapeutic strategies and explore alternatives to autologous nerve transplantation in clinical practice, based on the knowledge of the peripheral nerve regeneration mechanism and biological histocompatibility principles. With significant advances in the research and application of nerve conduits, they have been used to repair peripheral nerve injury for several decades. In this paper, the study background of nerve conduits, their applications in clinic, status of conduit material research and construction of tissue‐engineered artificial nerves were reviewed.

Controlled release of nerve growth factor and basic fibroblast growth factor combined with small-gap anastomosis enhances sciatic nerve regeneration

Objectives: Nerve regeneration after peripheral nerve injury is a slow process with a limited degree of functional recovery, resulting ina 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(bF GF) 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 bF GF 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 Bor C, but the sciatic nerve function index, muscle wet weight, and thickness of myelination in the 3 groups were not significantly different3(P > 0.05). There were no significant differences innerve conduction velocitybetween 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 densityin 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 havea superior effect on nerve repair.