Sciatic Nerve Regeneration in Mice Using A PLGA Microgroove Patterned Conduit Fills with Microfiber

Abstract

Nerve conduit is one of common strategy for peripheral nerve repair in clinical, but the repairing process is slow and complex leading to a poor result of functional recovery. From neuroanatomy inspiration, a nerve conduit combine with micro groove patterned and microfiber for guiding nerve regeneration in animal test was evaluation in this study. The master mold of poly(lactic-co-glycolic acid) microgroove patterned membrane and microfiber were manufactured by photolithography and poly(dimethylsiloxane) casting. A bunch of microfiber was wrapped with micro-patterned membrane forming a filler type conduit (Conduit 2.0). The microgroove pattern only conduit was used as control group (Conduit 2.1). Sample was then implanted into injured FVB mice sciatic nerve for 8 week to emulate the trauma recovery. According to the SEM image, these micro structures were not degradation after 8 weeks implantation. The neurite outgrowth and cell migration on conduit can be modulated by mechanical causes of surrounding environment. However, some fragmentation microfibers were observed to disrupt the cell migrating direction, and interfered the guiding ability of microgroove patterned on inner wall. In Rotarod test, the mouse implanted using the conduit with microfiber showed a worse result compare to micro pattern only conduit at early stage, but did not show difference at final stage. The filling type conduit presented as dramatically poor recovery on the compound muscle action potential measurement after 8 weeks implantation, since the microfiber occupied most space leading to a lower mass transportation rate. In conclusion, microfiber filled conduit is a good tool for guide cell migration and neurite extension, but the degraded fragment and filling density still need to settle up to increase mass transportation inside conduit.