Hydrophilic interpenetrating polymer networks derived from hydrophobic polymers

Abstract

A composition having a hydrogel bearing side of a biostable polymer network, wherein the biostable polymer network comprises a first gradient of the biostable polymer, which biostable polymer network decreases in concentration from the hydrogel bearing side to a bone interface surface; and a second gradient of a biostable polyurethane network, which polyurethane network increases in concentration from the hydrogel bearing side to the bone interface surface, the bone interface surface useful for an orthopedic implant.

1 . An orthopedic implant device, said implant device comprising:
 a composition comprising two or more polymer networks having a hydrogel bearing side of a polymer network, wherein the polymer network comprises a first gradient of the polymer, which polymer network decreases in concentration from the hydrogel bearing side to a bone interface surface; and   a second gradient of a polyurethane network, which polyurethane network increases in concentration from the hydrogel bearing side to the bone interface surface, the bone interface surface of the polyurethane network comprises an osteochondral graft, wherein the orthopedic implant device is a cartilage replacement prosthesis.   
     
     
         2 . The orthopedic implant device of  claim 1 , wherein the polymer is polyacrylic acid, without polyethylene glycol. 
     
     
         3 . The orthopedic implant device of  claim 1 , wherein at least one of the networks is a covalently cross-linked network. 
     
     
         4 . The orthopedic implant device of  claim 1 , further comprising an antioxidant. 
     
     
         5 . The orthopedic implant device of  claim 1 , further comprising water. 
     
     
         6 . The orthopedic implant device of  claim 1 , wherein the polyurethane includes a pourous polyurethane, which is a bone anchoring layer. 
     
     
         7 . The orthopedic implant device of  claim 6 , wherein the porosity is made by incorporating a porogen into the polyurethane that is leached out. 
     
     
         8 . The orthopedic implant device of  claim 7 , wherein the bone interface surface is a bone-like porous structure. 
     
     
         9 . The orthopedic implant device of  claim 6 , wherein the porous polyurethane further comprises an osteoconductive agent. 
     
     
         10 . The orthopedic implant device of  claim 1 , wherein the hydrogel bearing side is a lubricious surface. 
     
     
         11 . The orthopedic implant device of  claim 1 , wherein the device has a shape selected from the group consisting of a cap, a cup, a plug, and a patch. 
     
     
         12 . The orthopedic implant device of  claim 1 , wherein the hydrogel bearing side is grafted to the polyurethane. 
     
     
         13 . The orthopedic implant device of  claim 12 , wherein the polyurethane network is grafted through vinyl end groups. 
     
     
         14 . The orthopedic implant device of  claim 12 , wherein the composition is a hybrid copolymer/interpenetrating polymer network. 
     
     
         15 . The orthopedic implant device of  claim 1 , wherein the polyurethane network comprises polycarbonate urethane, polycarbonate urethane urea, polyether urethane, polyether urethane urea, or a silicone-containing derivative of thereof. 
     
     
         16 . The orthopedic implant device of  claim 15 , wherein the polyurethane is a polyether urethane.