Neuronal alignment and outgrowth on microwrinkled conducting polymer substrates

We report on the results of culturing SH-SY5Y neuron-like cells on PEDOT:PSS wrinkled surfaces fabricated by thermally-induced shrinking of commercial polystyrene sheets. Such smart biointerfaces combine the functional properties of conducting polymers with the topographic patterning at the micro-and sub-microscale, as a result of surface wrinkling. By imposing mechanical constraints during shrinking, anisotropic topographic features are formed, with a spatial periodicity in the range 0.7-1.2 um, tunable by varying the thickness of the PEDOT:PSS thin film. The effectiveness of wrinkled surfaces in enhancing and orientating the outgrowth of neurites is demonstrated by a 42% increase in length and by the 85% of neuntes aligned along wrinkles direction (angle 0 < 9< 15°), after 5 days of differentiation. Furthermore, the conductive properties of the PEDOT:PSS film are retained after the surface wrinkling, opening the way for the exploitation of these smart biointerfaces for the electrical stimulation of cells.