Control of endothelial cell adhesion to polymer surface by ion implantation

The bio-compatibility of ion implanted polymers has been studied by means o f in vitro attachment measurements of bovine aorta endothelial cells. The s pecimens used were polystyrene (PS), polyethylene (PE), polypropylene (PP) and expanded polytetrafluoroethylene (ePTFE). He+ and Ne+ ion implantation were performed at an energy of 150 keV with fluences between I X 10(13) to 1 X 10(17) ions/cm(2) at room temperature. Wettability was estimated by mea ns of a sessile drop method. The chemical and physical structures of ion im planted polymers were investigated by contact angle measurements, atomic-fo rce microscopy and X-ray photoelectron spectroscopic analysis in relation t o cell attachment behavior. The strength of cell attachment on ion implante d specimens at static and under flow conditions was also measured. Ion impl anted PP and ePTFE were found to exhibit remarkably higher adhesion and spr eading of endothelial cells than non-implanted specimens. In contrast to th ese findings, ion implanted PS and PE only demonstrated a little improvemen t of cell adhesion in this assay. Copyright (C) 2001 John Wiley & Sons, Ltd .