Electrically conductive MEH-PPV:PCL electrospun nanofibres for electrical stimulation of rat PC12 pheochromocytoma cells

Abstract

The purpose of this study was to prepare an electrically conducting poly[2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) based nanofibrous scaffold and to investigate the synergetic effect of nanofibre structure and electrical stimulation on neuronal growth for possible use in nerve repair. Nanofibres were produced by electrospinning of blended MEH-PPV with polycaprolactone (PCL) at a ratio of 20 : 80, 40 : 60, 50 : 50 and 60 : 40 (v/v). A better electrical conductivity was achieved by using core-sheath structured nanofibres of PCL (core) and MEH-PPV (sheath) produced using the coaxial electrospinning technique. The highest electrical conductivity was observed in the core-sheath nanofibres, while it increased with increasing concentration of MEH-PPV for the blended electrospun nanofibres. The biocompatibility of the electrospun nanofibres was confirmed by MTS and live-dead staining assays using 3T3 fibroblasts and a neuronal rat pheochromocytoma (PC12) cell line. Beta (III) tubulin immunochemistry showed that PC12 cells differentiated into sympathetic neurons on these porous and stiffer electrospun nanofibres coated with collagen I. Improved cell morphology and attachment on the collagen I coated electrospun meshes has been confirmed by SEM analysis. Significant enhancement in neurite formation and neurite outgrowth of PC12 cells on the conductive scaffolds under electrical potential of 500 mV cm⁻¹ for 2 h day⁻¹ suggests the potential use of these scaffolds for nerve repair.