Biocompatible polymer film
The present invention includes a co-polymer film which can be applied over a surface of an article to form a continuous surface that is more biocompatible and has a smoother surface morphology than an untreated article. In general the co-polymer film of the invention can be formed by providing a hydrophobic polymer block, such as polydimethylsiloxane (PDMS) with functional —OH end groups and reacting the —OH ends with a conventional monomer or prepolymer of a film-forming polymer capable of reacting with —OH groups. Such reactions are exemplified, using as reactive PDMS a triblock copolymer of the polylactone-polysiloxane-polylactone (PL-PDMS-PL) type, or silicone polyesters. The —OH groups of the polylactone blocks can react with any of a variety of isocyanates in a suitable solvent to form a polymer having PDMS incorporated with its structure. The film can be applied to the surface of an article by any convenient means of coating the article with the reaction mixture in solvent, and allowing the solvent to evaporate.
1. A co-polymer film comprising a film-forming polymer component and a hydrophobic polymer block having reactive end groups, said film having a non-uniform surface characterized by domains of varied properties of hydrophobicity, roughness, hardness or other physico-chemically distinct patches, said domains having average diameters in the range 0.1 nm-100 nm, wherein the film-forming polymer is selected from the group consisting of polyurethanes, polyolefins, cellulosic polymers, polycarbonates, polyarylethersulfones, polysulfones, polyvinylchlorides, and polyamides, and the hydrophobic polymer block is selected from the group consisting of siloxane polymers, fluoropolymers, polyethyleneglycol-polydimethyl siloxane co-polymers, silicone polyesters and polylactone-polysiloxane-polylactone triblock co-polymers.
2. The co-polymer film of claim 1 wherein the film-forming polymer is a polyurethane and the hydrophobic polymer block is a polylactone-polysiloxane-polylactone triblock co-polymer.
3. The co-polymer film of claim 1 wherein the film-forming polymer is a polydiphenyl methane diisocyanate prepolymer and the hydrophobic block is a polycaprolacton-polydimethylsiloxane-polycaprolactone triblock co-polymer.
4. The film of claim 3 wherein prior to condensation, the proportion of —OH groups on the hydrophobic block to —NCO groups on the film-forming polymer is in the range of 0.1 to 10.0.
5. A method of making a co-polymer film comprising the steps of:
a) combining a film-forming polymer component and a hydrophobic polymer block having end groups reactive with the film-forming polymer component in the presence of a solvent such that all components are dissolved in the solvent, wherein the film-forming polymer is selected from the group consisting of polyurethanes, polyolefins, cellulosic polymers, polycarbonates, polyarylethersulfones, polysulfones, polyvinylchlorides, and polyamides, and the hydrophobic polymer block is selected from the group consisting of siloxane polymers, fluoropolymers, polyethylenealycol-polydimethyl siloxane co-polymers, silicone polyesters and polylactone-polysiloxane-polylactone triblock co-polymers;
(b) applying the components dissolved in the solvent to a surface to be coated; and
(c) forming a film over the surface to be coated under conditions that allow the solvent to evaporate and the components to react with one another,
whereby a co-polymer film having a non-uniform surface characterized by domains of varied properties of hydrophobicity, roughness, hardness or other physico-chemically distinct patches, and said domains having average diameters in the range 0.1 nm-100 nm, is obtained.
6. The method of claim 5 wherein the film-forming polymer component is a polyurethane-forming component and the hydrophobic block is a polylactone-polysiloxane-polylactone triblock co-polymer.
7. The method of claim 6 wherein, prior to reaction, the proportion of —OH groups on the hydrophobic block to —NCO groups on the film-forming polymer is in the range from 0.1 to 10.0.
8. A The method of claim 6 where in the film-forming polymer component consists essentially of a mixture of an isocyanate and a polyol.
9. The method of claim 5 wherein the step of applying the components dissolved in the solvent to a surface to be coated is carried out by immersing an article to be coated by the film in the solution, then removing the article to permit the solvent to evaporate.
10. The method of claim 5 wherein the surface to be coated has been pre-coated with a layer comprising a polyol, or a polylactone-polysiloxane-polylactdone triblock co-polymer.
11. A method of coating a surface with a biocompatible co-polymer film comprising the steps of:
(a) covering the surface with a solution comprising a film-forming polymer component and a hydrophobic polymer block component having end groups reactive with the film-forming polymer component, the components being dissolved in a solvent, wherein the film-forming polymer is selected from the group consisting of polyurethanes, polyolefins, cellulosic polymers, polycarbonates, polyarylethersulfones, polysulfones, polyvinylchlorides, and polyamides, and the hydrophobic polymer block is selected from the group consisting of siloxane polymers, fluoropolymers, polyethyleneglycol-polydimethyl siloxane co-polymers, silicone polyesters and polylactone-polysiloxane-polylactone triblock co-polymers; and
(b) removing the solvent from the solution covering the surface to allow the components react with one another, whereby a co-polymer film having a non-uniform surface characterized by domains of varied properties of hydrophobicity, roughness, hardness or other physico-chemically distinct patches, and said domains having average diameters in the range 0.1 nm-100 nm, is formed on the surface.
12. The method of claim 11 wherein the film-forming polymer component is a polyurethane-forming component and the hydrophobic block is a polylactone-polysiloxane-polylactone triblock co-polymer.
13. The method of claim 12 wherein prior to reaction, the proportion of —OH groups on the hydrophobic block to —NCO groups on the film-forming polymer is in the range from 0.1 to 10.0.
14. The method of claim 12 wherein the film-forming polymer component consists essentially of a mixture of an isocyanate and a polyol.
15. The method of claim 11 wherein the surface has been pre-coated with a layer comprising a polyol, or a polylactone-polysiloxane-polylactone triblock co-polymer.
16. The method of claim 15 comprising the added step of forming a film over the pre-coating, prior to forming the bio-compatible co-polymer film.