The application discloses a method for the preparation (by extruding, injection molding or powder coating and subsequent cross-linking by irradiation with UV or visible light) of a medical device element involving a coating composition comprising: a) as the only polymer constituent(s), at least 50% by weight of poly(ethylene oxide)(s) optionally in combination with non-thermoplastic hydrophilic polymer(s), and b) low molecular weight scaffold(s) having a plurality of photo-initiator moieties covalently linked thereto and/or covalently incorporated therein, wherein the photo-initiator moieties constitute 0.01-20% by weight of the combined amount of the poly(ethylene oxide)(s), any non-thermoplastic hydrophilic polymers and the low molecular weight scaffolds. The application further discloses such extruded, injection molded or powder coated medical devices having thereon a layer of a covalently cross-linked coating composition of a poly(ethylene oxide) (PEO), optionally a non-thermoplastic hydrophilic polymer and a low molecular weight scaffold having a plurality of residues of photo-initiator moieties.