Disclosed is a urological device comprising a polymeric prosthesis coated on its surface by a grafted or interpenetrated hydrogel copolymer comprising 2-hydroxyethyl methacrylate, methacrylic acid, and a crosslinking agent, wherein each constituent of said copolymer is present in an amount selected from a defined range of mole fraction %. The hydrogel exhibits a shrink/swell behavior which varies with changing urine composition such that the polymer undergoes swelling and collapse in rapid response to said change and thereby prevents calcium encrustation. Also disclosed is a method for making the device.