Effect of Nano-to Micro-Scale Surface Topography on the Orientation of Endothelial Cells

The effect of grating textures on the alignment of cell shape and intracellular actin cytoskeleton has been investigated in bovine aortic endothelial cells (BAECs) cultured on a model cross-linked poly(dimethylsiloxane) (PDMS). Grating-textured PDMS substrates, having a variation in channel depths of 200 nm, 500 nm, 1 pm and 5 pm, were coated with fibronectin (Fn) to promote endothelial cell adhesion and cell orientation. As cells adhered to the Fn-coated surface, the underlying grating texture has shown to direct the alignment of cell shape, F-actin and focal contacts parallel to the channels. Cell alignment was observed to increase with increasing channel depths, reaching the maximum orientation where most cells aligned parallel to channels on 1-pm textured surface. Immunofluorescence studies showed that F-actin stress fibers and vinculin at focal contacts also aligned parallel to the channels. Cell proliferation was found to be independent of grating textures and the alignment of cell shape was maintained at confluence.