Microscopical evaluation of nerve guidance channel (NGC) internal surface microgeometry and material biostability

The peripheral nervous system (PSN) has regenerative capability. So, after an injury, axons can repair the gap between the stumps if it is not too large. To avoid this problem surgeon use the technique of the suture under tension or nerve grafting supported by NGC. The influence of inner surface (lS) microgeometry of NGC on nerve regeneration has already been reported in literature. NGCs featuring a smooth lS allow a better regeneration of the nerve cable. We manufactured polyurethane (PU) NGCs with a highly smooth lS and evaluated them by AFM and SEM. AFM of PU-NGCs show roughness less than 600 nm, whereas comparative silicone NGCs show roughness over 1400 nm. lmplantation experiments of PU-NGCS show, after 6-8 week, a good channel biostability and excellent regeneration of the nerve cable. SEM of the PU-NGCs show no evidence of microcracking in the external surface with a well regenerated nerve cable inside.