Nanoscaffold's stiffness affects primary cortical cell network formation

Networks of neurons cultured on-chip can provide insights into both normal and disease-state brain function. The ability to guide neuronal growth in specific, artificially designed patterns allows us to study how brain function follows form. Primary cortical cells cultured on nanograting scaffolds, in particular astrocytes, showed highly ordered regions of dendritic outgrowth. Usually, materials suitable for nanopatterning have a stiffness far above that of the extracellular matrix. In this paper, the authors studied two materials with large differences in stiffness, polydimethylsiloxane (PDMS) and silicon. Our results show that both nanopatterned silicon and PDMS guide the outgrowth of astrocytes in cortical cell culture, but the growth of the astrocyte is affected by the stiffness of the substrate, as revealed by differences in the cell soma size and the organization of the outgrowth.