Nerve conduit constructed by aligned chitosan nanofibers for directing axonal growth in nerve regeneration

Abstract

Schwann cell-seeded conduit have been exploited to bridge and guide axonal regrowth across gaps in injured nerves. By orienting the Schwann cell growth on aligned nanofibers, we hypothesized that axonal growth can be guided along the designated direction towards the target and the axons be myelinated for functional recovery. Chitosan, given its biocompatibility and the tunable susceptibility to biodegradation, was chosen for electrospinning aligned nanofibers by using a high speed rotating drum collector. The aligned chitosan nanofibers was used for cell culture. In 2D cultures, Schwann cells, dissociated dorsal root ganglia (DRG, E14/15 rats) cells and DRG explant endogenous cells were directed by the aligned nanofibers. The axons in DRG explant cultures were myelinated by the endogenous Schwann cells. To achieve transplantable nerve conduit, the 2D cell seeded aligned chitosan nanofibers sheet was rolled into a 3D spiral structured nerve conduit. Z-stack confocal images showed that both Schwann cell seeded and DRG explant one-end-seeded nerve conduit obtain cell alignment along the nanofibers which is also the longitudinal axis of the nerve conduit. Myelination occurred in the DRG explant in vitro results provided proof-of-principle for pursuing improvement in post-traumatic recovery from nerve injury with the use of Schwann cell-seeded aligned chitosan nanofibers as a nerve guidance conduit.