Preparation of PEG-coated surfaces and a study for their interaction with living cells

Cell-biomaterial interaction is of great importance for the development of bioinert as well as of hybrid surfaces. This study represents our results o f human fibroblast interaction with PEG-coated surfaces of differing length and structure (linear or branched) of the oxyethylene chain. We employed t hree PEGs - PEG 1500 and PEG 6000, both linear but with different chain len gths, and PEG 12 500 which was branched. The PEGs were deposited on silica plates using branched poly(ethylene imine) as an anchoring polymer. Fibrobl asts were plated and studied by immunofluorescence to evaluate the overall cell morphology, the organisation of the actin cytoskeleton, and the beta(1 )-integrin (fibronectin receptor). The particular effect of fibronectin (FN ) pre-adsorption was studied. Our results suggest that PEG 6000 surface is to be preferable with respect to the initial interaction with the cells. Th e overall cell morphology was almost normal on bare surfaces. FN pre-coatin g additionally improved cell adhesion and spreading as well as the organiza tion of the actin cytoskeleton and focal adhesion formation; the PEG 12 500 surface showed relatively poor initial properties. Almost no cell spreadin g was found on the bare surface, but FN pre-adsorption completely restored normal cell morphology. In contrast, PEG 1500 had to be considered as 'the worst' material, because of lower initial cell adhesion and spreading and F N pre-adsorption did not restore normal cell morphology.