Nano- and Micro-Structured Substrates for Neuronal Cell Development

We investigated neurite development in a rat pheochromocytoma cell line (PC12) cultured on nanostructured, micro-structured and smooth substrates. On nano-structured substrates, cells continued to proliferate and developed shorter neurites and numerous filopodia as compared with smooth substrates. On micro-structured substrates, by contrast, cells ceased to proliferate and developed multiple and longer neurites. Additionally, cells grown on nano-structured substrates did not show any increase in acetylcholinesterase activity—a measure of cell differentiation activities, whereas cells grown on micro-structured substrates did. Thus by both morphological and biochemical criteria, nano-structured substrates inhibit and micro-structured substrates enhance PC12 differentiation. These results suggest the possibility of using substrates with topographical features at the nanometer or micrometer scales to control cell growth, such as using nano-substrates to promote cell proliferation and using micro-substrates to promote cell differentiation.