Chondrotinase ABC enhances axonal regeneration across nerve gaps

We evaluated the effects of chondroitinase ABC on axonal regeneration across peripheral nerve gaps. We compared axonal regeneration after 15-mm tibial nerve resection and repair with a silicone tube filled with type I collagen gel (negative control group), with a silicone tube filled with type I collagen gel containing chondroitinase ABC at three different concentrations (2.5 units/mL, 5 units/mL, 10 units/mL) (chondroitinase ABC groups), and with an autologous nerve segment (nerve autograft group). Electrophysiological and histological assessments were carried out 12 weeks after surgery. In the electrophysiological study, compound muscle action potentials (CMAPs) and nerve conduction velocities (NCVs) were recorded in all groups except the negative control group. Although both CMAPs and NCVs were highest in the nerve autograft group, there were no significant differences among the three chondroitinase ABC groups in either parameter. Histological findings were consistent with electrophysiological results. Based on these findings, we conclude that topical injection of chondroitinase ABC can significantly increase the critical length of nerve gap repair by tubulization or artificial nerve placement.