Use of Schwann cell-seeded nanofiber as nerve conduit

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 in trifluoroacetic acid/methylene chloride solution was electrospun onto a high speed rotating drum and harvested followed by use of sodium carbonate to neutralize residual acidity and thus stabilize the nanofiber preparation in physiological environment. Schwann cells aligned uniaxially with the stabilized chitosan nanofibers mounted on a coverslip. In addition, by seeding dissociated cells of dorsal root ganglia (DRG, E14/15 rats) onto the 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. In translating from 2D culture to 3D culture, the Schwann cell-seeded nanofiber preparation was rolled into a model of nerve conduit and further maintained in culture. The Schwann cells remained in alignment along the longitudinal axis of the conduit. These in vitro results provide proof-of-principle for pursuing improvement in posttraumatic 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.