Preparation of chitosan fibers for nerve regeneration

Abstract

Schwann cells have been exploited to guide axonal regrowth after nerve injury. However, mis-orientation of Schwann cells in nerve guidance channels can hinder axonal growth across the lesion site. We therefore propose to orient the growth of Schwann cells on uniaxially aligned fibres such 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. With a conventional electrospinning setup and chitosan dissolved in trifluoroacetic acid/methylene chloride, our initial attempts resulted in a random orientation of chitosan fibers at the cathodic collector. By replacing the grounded plate collector with parallel collector plates placed 1.6 cm apart, the positively charged chitosan fibers became alternately attracted to the parallel plates and ended up uniaxially aligned as fibre suspension across the plates. Stability of the chitosan fibers in aqueous, physiological environment was achieved with use of sodium carbonate to neutralize residual acidity in the chitosan fiber preparation. Cell culture experiments are ongoing to test if Schwann cell behavior varies with fiber thickness of the stabilized chitosan fiber preparations.