Increasing fibroblast response to materials using nanotopography: morphological and genetic measurements of cell response to 13-nm-high polymer demixed islands.

It is becoming clear that cells can respond not only to micometric scale topography, but may also to nanometric scale topography. The production of reproducibly sized nanometric features has relied heavily on expensive and time-consuming methods of manufacture, such as electron beam lithography. Polymer demixing of polystyrene and polybromostyrene has been found to produce nanoscale islands of reproducible height, and the islands have been previously shown to effect cell spreading compared to planar surfaces. This study observes morphological, cytoskeletal, and molecular changes in fibroblast reaction to 13-nm-high islands. The methods employed include scanning electron microscopy, fluorescent microscopy, and 1718 gene microarray. The results show that the cells respond to the islands by broad gene up-regulation, notably in the areas of cell signaling, proliferation, cytoskeleton, and production of extracellular matrix proteins. Microscopical results provide confirmation of the microarray findings.