Neuroregenerative effects of olfactory ensheathing cells transplanted in a multi-layered conductive nanofibrous conduit in peripheral nerve repair in rats

BACKGROUND: The purpose of this study was to evaluate the efficacy of a multi-layered conductive nanofibrous hollow conduit in combination with olfactory ensheathing cells (OEC) to promote peripheral nerve regeneration. We aimed to harness both the topographical and electrical cues of the aligned conductive nanofibrous single-walled carbon nanotube/ poly ((L)-lactic acid) (SWCNT/PLLA) scaffolds along with the neurotrophic features of OEC in a nerve tissue engineered approach. RESULTS: We demonstrated that SWCNT/PLLA composite scaffolds support the adhesion, growth, survival and proliferation of OEC. Using microsurgical techniques, the tissue engineered nerve conduits were interposed into an 8 mm gap in sciatic nerve defects in rats. Functional recovery was evaluated using sciatic functional index (SFI) fortnightly after the surgery. Histological analyses including immunohistochemistry for S100 and NF markers along with toluidine blue staining (nerve thickness) and TEM imaging (myelin sheath thickness) of the sections from middle and distal parts of nerve grafts showed an increased regeneration in cell/scaffold group compared with cell-free scaffold and silicone groups. Neural regeneration in cell/scaffold group was very closely similar to autograft group, as deduced from SFI scores and histological assessments. CONCLUSIONS: Our results indicated that the tissue engineered construct made of rolled sheet of SWCNT/PLLA nanofibrous scaffolds and OEC could promote axonal outgrowth and peripheral nerve regeneration suggesting them as a promising alternative in nerve tissue engineering.