Covalently-bound, hydrophilic coating compositions for surgical implants

1. A copolymeric coating composition for a surgical implant wherein the coating composition is capable of absorbing from at least 5 to about 90% water and comprises

(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; and

(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.

2. The coating composition of claim 1 wherein the hydrophilic monomer is selected from the group consisting of acrylamides.

3. The coating composition of claim 2 wherein the coating composition comprises an acrylamide selected from the group consisting of hydroxyethyl methacrylamide and aminopropyl methacrylamide.

4. The coating composition of claim 1 wherein the coating composition is capable of absorbing from about 30 to about 80% water.

5. The coating composition of claim 1 wherein the coating composition is capable of absorbing from about 40 to about 60% water.

6. The coating composition of claim 1 wherein A is CH 3 , B is (CH 2 ) m , m is 2–5, Y is nothing or O, w is 0–1, and D is H.

7. The coating composition of claim 1 wherein the hydrophobic aryl acrylic monomer is selected from the group consisting of 2-phenylethyl methacrylate; 3-phenylpropyl methacrylate; 4-phenylbutyl methacrylate; 5-phenylpentyl methacrylate; 2-benzyloxyethyl methacrylate; and 3-benzyloxypropyl methacrylate.

8. The coating composition of claim 1 wherein the coating composition comprises from about 10–60% of 2-phenylethyl (meth)acrylate, from about 5–70% of hydrophilic monomer and from about 20–40% of the reactive plasticizer.

9. The coating composition of claim 1 wherein the cross-linking agent is selected from the group consisting of blocked isocyanates and peroxides.

10. The coating composition of claim 9 wherein the cross-linking agent is imidazole blocked isocyanatoethyl methacrylamide.

11. The coating composition of claim 1 wherein the coating composition further comprises one or more ingredients selected from the group consisting of UV absorbers that are copolymerizable with the hydrophobic aryl acrylic monomer and hydrophilic monomer; blue-light blocking colorants that are copolymerizable with the hydrophobic aryl acrylic monomer and hydrophilic monomer; and chain transfer agents.

12. The coating composition of claim 1 wherein the reactive plasticizer is polyethylene glycol (400) monomethylether monomethacrylamide.

13. The coating composition of claim 1 wherein the coating composition comprises a chain transfer agent selected from the group consisting of 1-dodecanethiol and 2-mercaptoethanol.