Bioartificial nerve grafts. A prototype.

A prototype for a bioartificial nerve graft has been developed. To set a baseline for a series of experimental studies we present a basic model in which multiple polyamide (nylon) filaments inside silicone tubes constitute an intrinsic and extrinsic framework, respectively, for regenerating axons. The prototype was used to bridge a 10 mm gap in rat sciatic nerve (n = 8). Four weeks postoperatively multiple axons organised into minifascicles were observed in all cases between the synthetic filaments and in the space between the filaments and the silicone tube. Pinching of the nerve distal to the prototype caused a response in 50% of the cases indicating the presence of regenerating sensory fibres compared with no response when no conduit had been used to bridge the gap. When an empty tube was used, pinching of the distal segment caused a response in all cases. The finding that regeneration is supported by the filament filled tubes forms a basis for further development of the bioartificial nerve graft concept with special reference to its potential for bridging extended gaps in nerve continuity.