Processing of biocompatible coating on polymeric implants

Abstract

The present invention provides polymeric substrates comprising a biocompatible coating and methods of preparation thereof. In particular, the coating may be a ceramic material, especially a calcium phosphate material, which may be functionally graded. The invention provides the ability to apply high quality coatings to polymeric substrates without damaging the substrate (e.g., melting the polymeric material). The functionally graded coating can provide crystalline calcium phosphate near the coating interface with the substrate and provide amorphous calcium phosphate at the outer surface of the coating.

1 . A biocompatible coated substrate comprising:
 a substrate having a surface formed of a polymeric material; and   a biocompatible coating layer comprising calcium phosphate overlying at least a portion of the substrate surface and bonded thereto; and   a thermal barrier coating between the substrate and the calcium phosphate coating layer;   the calcium phosphate in the coating layer being in a predominantly crystalline form in an area of the coating layer proximal to the substrate and being in a predominantly amorphous form in an area of the coating layer distal to the substrate.   
     
     
         2 . The coated substrate of  claim 1 , wherein the thermal barrier coating comprises a material selected from the group consisting of zirconia, yttrium stabilized zirconia, or combinations thereof. 
     
     
         3 . The coated substrate of  claim 1 , wherein said substrate is a prosthetic implant. 
     
     
         4 . The coated substrate of  claim 3 , wherein said prosthetic implant is selected from the group consisting of a dental implant and an orthopedic implant. 
     
     
         5 . The coated substrate of  claim 1 , wherein the polymeric material is polyetheretherketone (PEEK). 
     
     
         6 . The coated substrate of  claim 1 , wherein the polymeric material is carbon fiber reinforced PEEK. 
     
     
         7 . The coated substrate of  claim 1 , wherein the polymeric material is polyurethane. 
     
     
         8 . The coated substrate of  claim 1 , wherein the calcium phosphate coating has a thickness of about 100 nm to about 5 μm. 
     
     
         9 . The coated substrate of  claim 1 , wherein the calcium phosphate coating has a thickness of about 500 nm to about 5 μm. 
     
     
         10 . The coated substrate of  claim 1 , wherein the calcium phosphate is selected from the group consisting of hydroxyapatite, tricalcium phosphate, and mixtures thereof. 
     
     
         11 . The coated substrate of  claim 1 , wherein the thermal barrier coating comprises a metal component. 
     
     
         12 . The coated substrate of  claim 1 , wherein the thermal barrier coating comprises a metal oxide. 
     
     
         13 . The coated substrate of  claim 1 , wherein the calcium phosphate in the coating layer distal to the substrate is at least about 75% amorphous. 
     
     
         14 . The coated substrate of  claim 1 , wherein the calcium phosphate in the coating layer distal to the substrate is at least about 90% amorphous. 
     
     
         15 . The coated substrate of  claim 1 , wherein the calcium phosphate in the coating layer proximal to the substrate is at least about 70% crystalline. 
     
     
         16 . The coated substrate of  claim 1 , wherein the calcium phosphate in the coating layer proximal to the substrate is at least about 90% crystalline. 
     
     
         17 . The coated substrate of  claim 1 , wherein the biocompatible coating layer comprising calcium phosphate further comprises a component selected from the group consisting of zinc, magnesium, yttrium, and fluoride. 
     
     
         18 . The coated substrate of  claim 1 , wherein the biocompatible coating layer comprising calcium phosphate further comprises an antimicrobial or antibacterial component. 
     
     
         19 . The coated substrate of  claim 1 , wherein the biocompatible coating layer comprising calcium phosphate comprises calcium phosphate in an amount of at least 90% by weight. 
     
     
         20 . The coated substrate of  claim 1 , wherein the biocompatible coating layer comprising calcium phosphate comprises calcium phosphate in an amount of at least 98% by weight.