The present invention relates to a method for the preparation of a medical device element by means of extrusion or injection molding and to medical devices comprising such extruded or injection molded medical device elements. The medical device elements (e.g. tubes, wires, lines, stents, catheters, guides, endodontic instruments, needles, trocars for e.g. laparoscopic surgery, laparoscopic accessories, surgical instruments, guide wires) are characterized by a prefabricated shaped article or a thermoplastic substrate polymer having thereon a layer of a covalently cross-linked coating composition of a thermoplastic matrix polymer and a hydrophilic polymer. The method involves a coating composition comprising a thermoplastic matrix polymer, a hydrophilic polymer, and one or more photo-initiator(s), e.g. covalently linked to molecules of the thermoplastic matrix polymer and/or to molecules of the hydrophilic polymer. The coating composition is irradiated with UV or visible light so as to covalently cross-link said coating composition.