Characterization of Tin Oxide Coatings for Biomedical Applications

Micro-mechanical properties of calcium phosphate coatings for titanium prostheses

Mineralised tissue, such as bone and teeth, are composed of inorganic and organic components which are in intimate association with each other. The latter, and particularly proteins, serve not only to strengthen these tissues but also to stabilise their mineral contents. This is one of the main driving forces for coating metal implants with calcium phosphate layers which improve their biocompatibility and osteoconductive properties.

In a previous investigation [1] it has been demonstrated that when Bovine Serum Albumin (BSA) is biomimetically coprecipitated with Ca2+ and PO4 3- ions upon titanium alloy implants, it becomes incorporated into the crystal lattice and is not merely deposited on the surface. The BSA elicits a concentration-dependent change in the crystal structure of the coating (from an octacalcium phosphate type to a carbonated apatite one) and a decrease in its crystallinity. BSA-containing coatings thus bear a closer resemblance to natural bone mineral than do non-BSAcontaining ones.