Synthesis and characterization of substituted apatites for biomedical applications

Hydroxyapatite is a very well known ceramic biomaterial for its great similarity with the mineral part of the human bone. To increment its bioactivity, calcium, phosphate and hydroxils can be substituted with several species. In the present work, F-substituted hydroxyapatites nanopowders have been synthesized by a simple co-precipitation method and XRD/Rietveld refinement characterization has been performed to understand the influence of the F addition on structural properties such as lattice parameters, crystal size, phase composition, and crystallinity degree. An original ion-exchange chromatography characterization set-up has been developed to assess the real content of fluoride in the samples. Codoped Sr-F apatites have been synthesized and their structural characterization has been performed as described before. A simple method to fluorinate calcium phosphates powders in aqueous solution has been developed. Beta-TCP is found to be converted in F-rich hydroxhyapatite at pH=7.5.