Nerve guidance channel constructed by Schwann cell seeded aligned chitosan nanofiber

Abstract

Schwann cell-seeded guidance channels have been exploited to bridge and guide axonal re-growth across gaps in lesioned 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. Chitosan was the choice scaffold material given its biocompatibility and the tunable susceptibility to biodegradation. Chitosan was dissolved in trifluoroacetic acid/methylene chloride solution and was electrospun onto a high speed rotating drum. Stability of the chitosan fibers in aqueous, physiological environment was achieved with the use of sodium carbonate to neutralize residual acidity in the chitosan fiber preparation. Schwann cells seeded onto these stabilized aligned chitosan nanofibers aligned uniaxially with the chitosan nanofibers. In addition, by seeding dissociated cells of dorsal root ganglia (DRG, E14/15 rats) onto the uniaxially aligned nanofibers, both neurons and Schwann cells were aligned with the uniaxial arrangement of nanofibers. The Schwann cells could be induced to myelinate neurites extending from neuronal cell bodies. The Schwann cell-seeded nanofiber was rolled into a model of nerve conduit. The Schwann cell aligned along the longitudinal axis of the conduit. These in vitro results provide proof of principle for pursuing improvement in post-traumatic recovery from nerve injury with use of Schwann cell-seeded uniaxially aligned chitosan nanofibers as a nerve guidance channel. (Supported by ITS/100/ 10 of the Innovation and Technology Commission, HK Government).