Surface Modification of Poly(L-lactic acid) Nanofiber with Oligo(D-lactic acid) Bioactive-Peptide Conjugates for Peripheral Nerve Regeneration

In some traumatic nerve injuries, autologous nerve grafting is the first choice for bridging the gap between the severed nerve ends. However, this therapeutic strategy has some disadvantages, including permanent loss of donor function and requirement of multiple surgeries. An attractive alternative to this therapeutic technique is the use of artificial nerve conduit. Poly (L-lactic acid) (PLLA) is widely used as a substrate for artificial nerve conduit because it is readily biodegradable, but it is not inherently biologically active. In this study, we developed a PLLA nanofibrous nerve conduit, modified with a conjugate of oligo (D-lactic acid) (ODLA) and the neurite outgrowth, thereby promoting peptide AG73 (RKRLQVQLSIRT) to improve nerve regeneration. PLA/ODLA-AG73 nanofibrous conduit was fabricated by electrospinning and then transplanted at the 10 mm gap of rat sciatic nerve. After six months, electrophysiological evaluation revealed that it achieved better functional reinnervation than silicone tube (used as a reference) or unmodified PLLA nanofibrous conduit.