this invention relates to a new technique for preparing metal devices such as guidewires for the subsequent attachment of hydrophilic coatings . the invention also relates to guidewires and other devices made according to that method . in one embodiment of the method of this invention , a hydrocarbon residue undercoat is applied to a metal guidewire core by plasma deposition . a photoactive hydrophilic polymer is then deposited on the hydrocarbon residue coating and activated by ultraviolet light . the hydrocarbon residue coating acts as a tie layer between the hydrophilic polymer and the metal guidewire core apparently by providing c -- c bonds for the covalent linking of the coating material to the tie layer . the resulting article of this invention is a guidewire having the maneuverability of a metal guidewire and the biocompatibility of a lubricious , hydrophilic polymer .