Covalently-bound, hydrophilic coating compositions for surgical implants

1. A coated surgical implant comprising a coating and a substrate wherein the coating and the substrate are not identical, the coating is attached to the substrate by covalent bonds, the coating is from about 0.01 to about 1 μm thick, and the coating comprises a covalently cross-linked copolymer comprising

(i) a hydrophobic aryl acrylic monomer of the formula

wherein: A is H, CH 3 , CH 2 CH 3 , or CH 2 OH;

B is (CH 2 ) m or [O(CH 2 ) 2 ] n ;

C is (CH 2 ) w ;

m is 2–6;

n is 1–10;

Y is nothing, O, S, or NR, provided that if Y is O, S, or NR, then B is (CH 2 ) m ;

R is H, CH 3 , C n H 2n+1 (n=1–10), iso-OC 3 H 7 , C 6 H 5 , or CH 2 C 6 H 5 ;

w is 0–6, provided that m+w≦8; and

D is H, C 1 –C 4 alkyl, C 1 –C 4 alkoxy, C 6 H 5 , CH 2 C 6 H 5 or halogen;

(ii) a hydrophilic monomer selected from the group consisting of hydroxyalkyl (meth)acrylates; n-vinyl pyrrolidone and acrylamides;

(iii) a reactive plasticizer of the formula

wherein: X and X′ are independently H, CH 3 , CH 2 CH 3 , CH 2 CH 2 CH 3 , CH 2 OH, or

CH 2 CH 2 OH; and

n is 3–114, such that the average molecular weight of the polyethylene glycol

unit is 132–5000;

and a cross-linking agent, and wherein the covalently cross-linked copolymer is capable of absorbing from at least 5 to about 90% water.

2. The coated surgical implant of claim 1 wherein the substrate comprises a hydrophobic acrylic material.

3. The coated surgical implant of claim 1 wherein the covalently cross-linked copolymer comprises a hydrophilic monomer selected from the group consisting of acrylamides.

4. The coated surgical implant of claim 3 wherein the acrylamide is selected from the group consisting of hydroxyethyl methacrylamide and aminopropyl methacrylamide.

5. The coated surgical implant of claim 1 wherein the covalently cross-linked copolymer is capable of absorbing from about 30 to about 80% water.

6. The coated surgical implant of claim 1 wherein the covalently cross-linked copolymer comprises from about 10–60% of the hydrophobic aryl acrylic monomer, from about 5–70% of hydrophilic monomer and from about 20–40% of reactive plasticizer, and wherein the reactive plasticizer is polyethylene glycol (400) monomethylether monomethacrylamide.

7. The coated surgical implant of claim 3 wherein the implant is selected from the group consisting of intraocular lenses and contact lenses.