Surface treatment for silicone hydrogel contact lenses comprising hydrophilic polymer chains attached to an intermediate carbon coating
The present invention provides an optically clear, hydrophilic coating upon the surface of a silicone medical device by sequentially subjecting the surface of the lens to plasma polymerization in a hydrocarbon-containing atmosphere and then covalently attaching a preformed hydrophilic polymer to the surface of the carbon coating. The invention is especially useful for forming a biocompatible coating on a silicone contact lens.
1. A silicone medical device including a hydrophilic surface, wherein said surface comprises:
(a) a carbonaceous layer on the surface of the medical device; and
(b) hydrophilic polymer chains attached to the carbonaceous layer wherein the points of attachment are the result of the reaction of complementary reactive functionalities in monomeric units along the hydrophilic polymers with reactive functional i ties on the carbonaceous layer,
wherein the medical device is a silicone contact lens or a silicone intraocular lens.
2. A silicone medical device including a hydrophilic surface, wherein said surface comprises:
(a) a carbonaceous layer on the surface of the medical device; and
(b) hydrophilic polymer chains attached to the carbonaceous layer wherein the points of attachment are the result of the reaction of complementary reactive functionalities in monomeric units along the hydrophilic polymers with reactive functionalities on the carbonaceous layer,
wherein the medical device is a silicone hydrogel, continuous-wear contact lens.
3. The medical device of claim 1 , wherein the hydrophilic polymer chains attached to the medical device are the result of the reaction of isocyanate or ring-opening reactive functionalities in monomeric units along the hydrophilic reactive polymers with said reactive functionalities on the carbonaceous layer.
4. The medical device of claim 1 , wherein the hydrophilic polymer chains comprise 1 to 100 mole percent of monomeric units having reacted reactive functionalities and 0 to 99 mole percent of monomeric units that are derived from non-reactive hydrophilic monomers.
5. The medical device of claim 1 , wherein the reactive functionalities are derived from monomers containing one or more of the following groups; glycidyl, azlactone, isocyanate, and acid anhydride.
6. The medical device of claim 1 , wherein the hydrophilic monomeric units are derived from monomers selected from the group consisting of acrylamides, lactams, poly(alkyleneoxy)methacrylates, methacrylic acid or hydroxyalkyl methacrylates.
7. The medical devive of claim 1 ,
wherein the hydrophilic polymer chains comprises moieties along the chain represented by the general formula:
where R 3 and R 4 independently denote an alkyl radicals with one to six carbon atoms or a cycloalkyl radicals with 5 or 6 carbon atoms.
8. The medical device claim 1 , wherein hydrophilic polymer chains attached to the carbonaceous layer are the result of the reaction of a mixture of polymers comprising (a) a first hydrophilic reactive polymer having reactive functionalities in monomeric units along the hydrophilic polymers complementary to reactive functionalities on the carbonaceous layer and, in addition, (b) a second hydrophilic reactive polymer having supplemental reactive functionalities that are reactive with the first hydrophilic reactive polymer.