Surface properties and biocompatibility of ion-implanted polymers

Abstract

The surface properties of the polyethylene (PE), polypropylene (PP) and polystyrene (PS) samples doped with 150 keV F⁺ ions with doses of 1 × 10¹²-1 × 10¹⁵ cm^–2 have been characterized by different techniques and their biocompatibility to vascular smooth muscle cells was examined. The concentration and the conjugation length of the double bonds produced by ion impact, the conductivity and the surface polarity increased with the level of doping. The cell density was measured on the PP and PS samples doped with doses below 1 × 10¹³ cm^–2. The cells cultured on the ion-doped PS and PP exhibited better homogeneity and the resulting density was several times higher than that on the undoped polymers. No such effects were observed on the doped PE. The enhanced cell proliferation correlates with the increased surface polarity of the doped polymers.