In vitro reaction of endothelial cells to polymer demixed nanotopography.

The introduction of topography to material surfaces has been shown to strongly affect cell behaviour, and the effects of micrometric surface morphologies have been extensively characterised. Research is now starting to investigate the reaction of cells to nanometric topography. This study used polymer demixing of polystyrene and poly(4-bromostyrene) producing nanometrically high islands, and observed endothelial cell response to the islands. Three island heights were investigated; these were 13, 35 and 95 nm. The cells were seen to be more spread on the manufactured topographies than that on flat surfaces of similar chemistry. Other morphological differences were also noted by histology, fluorescence and scanning electron microscopy, with many arcuate cells noted on the test surfaces, and cytoskeletal alignment along the arcuate features. Of the nanotopographies, the 13 nm islands were seen to give the largest response, with highly spread cell morphologies containing well-defined cytoskeleton.