A method for the preparation of a medical device element, said method comprising the steps of: (i) providing a prefabricated shaped article and/or a thermoplastic substrate polymer; (ii) providing a coating composition comprising: (a) as the only polymer constituent(s), one or more poly(ethylene oxide)s, which do not carry any ethylenically unsaturated functionalities, optionally in combination with one or more non-thermoplastic hydrophilic polymers, said one or more poly(ethylene oxide)s constituting at least 50 % by weight of said polymer constituent(s), and (b) one or more low molecular weight scaffolds 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 one or more poly(ethylene oxide)s, any non-thermoplastic hydrophilic polymers and the one or more low molecular weight scaffolds, and wherein said low molecular weight scaffold is an organic compound having a weight average molecular weight in the range of 100-10,000 Da (g/mol); (iii) extruding, injection moulding or powder coating the coating composition of step (ii) on the prefabricated shaped article and/or the thermoplastic substrate polymer of step (i) so as to provide the medical device element of said prefabricated shaped article and/or said substrate polymer having thereon a layer of said coating composition, wherein, when both of said prefabricated shaped article and said substrate polymer are present, said prefabricated shaped article has thereon a layer of said substrate polymer; (iv) irradiating the coating composition with UV or visible light so as to covalently crosslink said coating composition. (i) providing a prefabricated shaped article and/or a thermoplastic substrate polymer; (ii) providing a coating composition comprising: (a) as the only polymer constituent(s), one or more poly(ethylene oxide)s, which do not carry any ethylenically unsaturated functionalities, optionally in combination with one or more non-thermoplastic hydrophilic polymers, said one or more poly(ethylene oxide)s constituting at least 50 % by weight of said polymer constituent(s), and (b) one or more low molecular weight scaffolds 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 one or more poly(ethylene oxide)s, any non-thermoplastic hydrophilic polymers and the one or more low molecular weight scaffolds, and wherein said low molecular weight scaffold is an organic compound having a weight average molecular weight in the range of 100-10,000 Da (g/mol); (a) as the only polymer constituent(s), one or more poly(ethylene oxide)s, which do not carry any ethylenically unsaturated functionalities, optionally in combination with one or more non-thermoplastic hydrophilic polymers, said one or more poly(ethylene oxide)s constituting at least 50 % by weight of said polymer constituent(s), and (b) one or more low molecular weight scaffolds 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 one or more poly(ethylene oxide)s, any non-thermoplastic hydrophilic polymers and the one or more low molecular weight scaffolds, and wherein said low molecular weight scaffold is an organic compound having a weight average molecular weight in the range of 100-10,000 Da (g/mol); (iii) extruding, injection moulding or powder coating the coating composition of step (ii) on the prefabricated shaped article and/or the thermoplastic substrate polymer of step (i) so as to provide the medical device element of said prefabricated shaped article and/or said substrate polymer having thereon a layer of said coating composition, wherein, when both of said prefabricated shaped article and said substrate polymer are present, said prefabricated shaped article has thereon a layer of said substrate polymer; (iv) irradiating the coating composition with UV or visible light so as to covalently crosslink said coating composition.