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.