Adhesion and proliferation of keratinocytes on ion beam modified polyethylene

Polyethylene (PE) foils were modified by irradiation with Ar+ and Xe+ ions to different fluences and different physico-chemical properties of the irradiated PE were studied in relation to adhesion and proliferation of keratinocytes on the modified surface. Changes in the PE surface roughness were examined using the AFM technique, the production of conjugated double bonds and oxidized structures by UV-VIS and FTIR techniques respectively. The surface polarity was determined by measuring surface contact angle and two-point technique was used for the determination of PE sheet resistance. Adhesion and proliferation of keratinocytes was characterized using the MTT-test. The ion irradiation leads to creation of conjugated double bonds which, together with progressive carbonization, contribute to the observed decrease of sheet resistance. Oxidation of the irradiated PE surface layer during the ion implantation is observed. Besides oxidation, the PE surface polarity is affected by other factors. The observed increase of the PE surface roughness due to the ion irradiation is inversely proportional to the ion size. The adhesion and proliferation of keratinocytes on the ion irradiated PE is significantly higher than on the pristine PE. Distribution of results in keratinocyte cultivation and the number of cells is related to the ion fluence applied and to ion species as well. (C) 2000 Kluwer Academic Publishers.