(437c) Increased Schwann Cell Migration Speed and Directionality Occurs During Electrical Stimulation Through Polypyrrole Substrates

Current injury models suggest that Schwann cell migration and guidance are necessary for successful regeneration and synaptic reconnection after peripheral nerve injury. The ability of conducting polymers such as polypyrrole to exhibit chemical, contact, and electrical stimuli has led to much interest in their use for neural conduits. Despite this interest very little research has investigated the effect that electrical stimulation using polypyrrole has on Schwann cell behavior. Here we investigate the mechanism by which Schwann cells interact with polypyrrole in the presence of an electric field. We explored the effect that adsorption of different serum proteins on polypyrrole upon the application of an electric field has on Schwann cell migration and secretion of key biomolecules (i.e., NGF, BDNF, and CNTF). The results show an increase in average displacement with electrical stimulation, resulting in a net anodic migration. Moreover, indirect effect of protein adsorption due to the oxidation of the film upon the application of electrical stimulation was shown to have a larger effect on migration speed than on migration directionality. These results suggest that SC migration speed is governed by integrin mediated interactions with adsorbed proteins; whereas SC migration directionality is governed by electrically mediated phenomena.   These results will prove invaluable in optimizing conducting polymers for their different biomedical applications such as nerve repair.