Directional PC12 cell migration along plastic nanotracks.

The design of materials to promote the development and/or regeneration of neuronal tissue requires the understanding of the mechanisms by which the underlying substrate topography can modulate neuronal cell differentiation and migration. We recently demonstrated that plastic nanogratings (alternating lines of grooves and ridges of submicrometer size) can effectively change the neuronal polarity state, selecting bipolar cells with aligned neurites. Here, we address the effect of nanogratings on the migration properties of differentiating PC12 cells and correlate their behavior with the polarity state induced by the substrate. During neuronal differentiation, cell-substrate interaction is sufficient to induce directional migration along the nanogratings. Control cells contacting flat substrates migrated freely in all directions, while cells differentiating on nanogratings showed slower migration characterized by an angular restriction that confined cell movements. Finally, we show that directional migration on nanogratings is linked to a specific organization of the cell cytoskeleton reflecting the nanograting directionality.