The plasma polymerization of acetone has been used to modify polystyrene substrates for the controlled growth of human fibroblast cells. The surface modified polystyrene was studied by X-ray photoelectron spectroscopy, water contact angle and atomic force microscopy. This showed the surface oxygen levels and wettability to increase rapidly with exposure to the acetone plasma. High-resolution XPS allowed the determination of the relative amounts of surface hydroxyl, carbonyl and carboxyl groups. This showed that there was little incorporation of carboxyl groups in the deposited films. AFM measurements revealed the films to be conformal with a surface roughness equivalent to that of the underlying polystyrene Substrate with film growth rates of approximately 0.5 nm min-1. High edge-definition patterns were produced with a simple masking procedure and allowed the confinement of cells to selected areas of the substrate. These chemically patterned surfaces allowed the study of cells confined to particular regions of the substrate as a function of incubation time. (C) 2004 Elsevier Inc. All rights reserved.