Process for preparation of slippery, tenaciously adhering, hydrophilic polyurethane hydrogel coating, coated polymer and metal substrate materials, and coated medical devices

A sterilized coating of a reactivatable, dried, hydrophilic polyurethane-polyurea hydrogel, on the surface of a medical device fabricated from a polymeric substrate, said sterilized coating being produced by a process comprising:

• a) making at least a portion of an outer surface of said polymeric substrate from which said medical device is fabricated, chemically reactive by affixing reactive chemical functional groups thereto;
• b) coating the resulting reactive outer surface of said substrate with a first coating comprising a hydrophilic polyurethane-urea prepolymer intermediate, which is capable of forming a polyurethane-polyurea hydrogel-forming polymer, and which contains terminal isocyanate groups, such that at least a portion of said terminal isocyanate groups are reacted with and are covalently bonded to said reactive chemical functional groups on said surface of said substrate, forming covalent polyurea bonds therewith, resulting in the formation of a tie coat of a polyurethane-polyurea hydrogel-forming polymer, that adheres to said reactive outer surface of said substrate, and wherein at least a portion of said terminal isocyanate groups of said polyurethane-urea prepolymer intermediate are present in said polyurethane-polyurea hydrogel-forming polymer, such that they remain free to react with other species;
• c) coating said tie coat with a second coating comprising a moisture-containing hydrogel-forming compound, further containing isocyanate-reactive chemical functional groups, such that a barrier coat of a lubricious, hydrated hydrogel is formed upon the application of said second coating to said tie coat of said first coated substrate;
• wherein said isocyanate-reactive functional groups of said moisture-containing hydrogel-forming compound are reacted with and are covalently bonded to at least a portion of said terminal isocyanate groups of said polyurethane-polyurea hydrogel-forming polymer that remain free to react with other species, to form a hydrated, hydrophilic polyurethane-polyurea polymer hydrogel, that is directly adhering to said tie coat, and thus also indirectly adhering to said substrate surface;
• d) drying said hydrated, hydrophilic polyurethane-polyurea hydrogel coating formed in step (c) to form a dried hydrogel coating thereof;
• and
• e) sterilizing the resulting coated medical device, bearing said dried hydrogel coating of step (d).