The effect of four types of artificial nerve graft structures on the repair of 10‐mm rat sciatic nerve gap

Investigating the effect of four types of artificial nerve graft (ANG) structures on rat sciatic nerve defect repair will aid future ANG designs. In this study, fibroin fibers and polylactic acid were used to prepare four ANGs with differing structures: nerve conduit with micron‐sized pores (Conduit with pore group), nerve conduit without micron‐sized pores (Conduit group), nerve scaffold comprising Conduit with pore group material plus silk fibers (Scaffold with pore group), and nerve scaffold comprising Conduit group material plus silk fibers (Scaffold group). ANGs or autologous nerves (Autologous group) were implanted into 10 mm rat sciatic nerve defects (n = 50 per group). Twenty weeks after nerve grafting, the time required to retract the surgical limb from the hot water was ranked as follows: Conduit with pore group > Scaffold with pore group > Conduit group > Scaffold group > Autologous group. The static sciatic index was ranked in descending order: Autologous group > Scaffold group > Conduit group > Scaffold with pore group > Conduit with pore group. Immunofluorescence staining identified significant differences in the distribution and number of axons, Schwann cells, and fibroblasts. These findings indicate that ANGs with micron‐sized pores had a negative impact on the repair of peripheral nerve defects, while internal microchannels were beneficial. © 2017 The Authors. Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3077–3085, 2017.