RADIATION-INDUCED MODIFICATION OF POLYETHERURETHANE FILMS AND TUBES - PLATELET-ADHESION AND INVIVO EXPERIMENTS

The measurement of platelet adhesion to polyetherurethane films grafted (via the preswelling technique) with 2-hydroxyethyl methacrylate (HEMA) and acrylamide (AAm), performed by means of the stagnation point flow experiment (SPFE-test) as well as with the aid of the bioluminescence assay, is described. Platelet adhesion is found to decrease if the interfacial free energy gamma //s//w of the polymer surfaces decreases. Adhesion to protein-coated, grafted polyetherurethane films (coated with albumin, gamma -globulin, fibrinogen, fibronectin or a protein mixture) depends on the nature of the protein used: precoating of the films with albumin or gamma -globulin leads to a decrease; precoating with fibrinogen or fibronectin to an increase in platelet adhesion. Also we report about early experiences with HEMA-grafted polyetherurethane tubes in implantation experiments.