Process for producing slippery, tenaciously adhering hydrogel coatings containing a polyurethane-urea polymer hydrogel commingled with a poly (n-vinylpyrrolidone) polymer hydrogel

A process for producing a material bearing thereon a dried coating of an adhering, commingled hydrogel of a hydrophilic polyurethane-polyurea polymer hydrogel and a poly(N-vinylpyrrolidone) polymer hydrogel, which is regenerable by re-exposure to moisture, said process comprising:

• a) affixing reactive chemical functional groups, at least some of which are amine-containing groups, to a surface of a hydrophilic or hydrophilicized hydrophobic polymer substrate or a metal substrate to make a reactive substrate surface;
• b) coating the resulting reactive surface of (a) 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 some of said terminal isocyanate groups are reacted with and are covalently bonded to said reactive chemical functional groups on said substrate surface, forming covalent polyurea bonds therewith, resulting in the formation of a tie coat of a polyurethane-polyurea hydrogel-forming polymer, which adheres to said reactive substrate surface, and wherein at least some of said terminal isocyanate groups in said polyurethane-polyurea hydrogel-forming polymer remain free to react with other species;
• c) treating said resulting tie coat of (b) with a treatment selected from the group (i-ii) consisting of:
• (i) applying a second coating comprising an aqueous solution of a poly(N-vinylpyrrolidone) hydrogel-forming polymer;
• (ii) applying a second coating comprising an aqueous solution of a poly(N-vinylpyrrolidone) hydrogel-forming polymer, followed by application, in a vapor phase, of a moisture-containing substance, such that a barrier coat which is a commingled hydrogel of a hydrophilic polyurethane-polyurea polymer hydrogel and a poly(N-vinylpyrrolidone) hydrogel is formed;
• wherein water of said aqueous solution or said moisture-containing substance is bound with said polyurethane-polyurea hydrogel-forming polymer forming said polyurethane-polyurea polymer hydrogel;
• wherein water of said aqueous solution or said moisture-containing substance is bound with said poly(N-vinylpyrrolidone) hydrogel-forming polymer forming said poly(N-vinylpyrrolidone) polymer hydrogel;
• and
• wherein said poly(N-vinylpyrrolidone) polymer hydrogel is adherent to said substrate surface as a result of being commingled with said polyurethane:
• polyurea polymer hydrogel;
• and
• (d) further performing a drying of said wet, slippery, adhering, commingled hydrogel of a polyurethane-polyurea polymer hydrogel and a poly(N-vinylpyrrolidone) polymer hydrogel of (c), to form a reactivatable dried coating thereof.

A process for producing a sterilized coating of a reactivatable, dried, adhering, commingled hydrogel of a hydrophilic polyurethane-polyurea polymer hydrogel and a poly(N-vinylpyrrolidone) polymer hydrogel, on the surface of a medical device fabricated from a polymeric substrate or a metallic substrate, said process comprising:

• (a) making at least a portion of an outer surface of said polymeric or metallic substrate from which said medical device is fabricated chemically reactive by affixing reactive chemical functional groups, including at least some amine-containing 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 some of said terminal isocyanate groups are reacted with and are covalently bonded to said reactive chemical functional groups on said outer surface of said polymeric or metallic 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 some 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 poly(N-vinylpyrrolidone) hydrogel-forming polymer, and a moisture-containing, hydrogel-forming substance, which also contains isocyanate-reactive chemical functional groups, such that a barrier coat of a wet, slippery, commingled 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 hydrogel-forming substance are reacted with and are covalently bonded to at least some of said terminal isocyanate groups of said polyurethane-polyurea hydrogel-forming polymer that remain free to react with other species, to form a first hydrogel of said commingled hydrogel barrier coat, such that said first hydrogel of said commingled hydrogel barrier coat is a polyurethane-polyurea polymer hydrogel that adheres to said tie coat, and thus also adheres to said substrate surface;
• wherein said moisture of said hydrogel-forming substance is bound with said poly(N-vinylpyrrolidone) hydrogel-forming polymer, to form a second hydrogel of said commingled hydrogel barrier coat, such that said second hydrogel of said commingled hydrogel barrier coat is a poly(N-vinylpyrrolidone) polymer hydrogel;
• and
• wherein said first hydrogel of said commingled hydrogel barrier coat and said second hydrogel of said commingled hydrogel barrier coat are commingled with one another, such that said second hydrogel of said commingled hydrogel barrier coat is thereby rendered adhering to said tie coat and thus also adhering to said substrate surface;
• (d) drying said wet, slippery commingled hydrogel barrier coat formed in (c) to form a dried hydrogel coating thereof;
• and
• (e) sterilizing the resulting coated medical device, bearing said dried hydrogel coating of (d).