Figure 4.

Neurite outgrowth of PC12 cells cultured on regular PPy films (grey bars) and on PPy-NSE₅₀ (black bars). The PC12 cells were cultured for 5 days, fixed with 4% paraformaldehyde and stained with phalloidin–TRITC. Without NGF treatment either in the medium or on the surface, there were few cells bearing neurites. For the positive controls, approximately 25–27% of the PC12 cells cultured in NGF-containing medium (50 ng ml⁻¹) extended neurites. NGF-conjugated PPy-NSE₅₀ films (black bars) promoted neurite extension similarly to positive controls, but significantly higher than NGF-treated PPy-NSE₀ films (grey bars). Five independent experiments were performed. ^* p<0.005.