Biocompatibility of oxygen-plasma-treated polystyrene substrates A. Vesel, M. Mozetic, M. Jaganjac, L. Milkovic, A. Cipak and N. Zarkovic Eur. Phys. J. Appl. Phys., 56 2 (2011) 24024 Published online: 28 October 2011 DOI: 10.1051/epjap/2011110169