Enhanced neuronal outgrowth on electrically charged polymers is dependent on bulk versus surface properties

This study demonstrates that piezoelectric polymer substrates induce substantially higher levels of neuronal differentiation and neurite outgrowth than electrically neural substrates in the absence of other cell types. Enhanced differentiation is due to piezoelectric output rather than changes in surface structure or chemistry since; 1) ESCA and contact angle data reveal that poled and unpoled surfaces are indistinguishable, 2) results were similar for uni- or biaxially stretched PVDF and 3) results were similar for PVDF and p(VDF-TrFE). Electrically charged fluoropolymers represent a unique class of biomaterials whose bulk properties are of greater importance in mediating cell/polymer interactions than their surface properties.