Barium and Fluorine Doped Synthetic Hydroxyapatite: Characterization and In-Vitro Bioactivity Analysis

We have successfully doped hydroxyapatite (HA) with barium (Ba²⁺) and fluoride (F^–) ions to furnish Ca_{10– x} Ba _x (PO₄)₆(OH)_{2– y} F _y , (where x = 0–1 and y = 1) by using microwave assisted wet precipitation method. The resulting powders were characterized by using X-ray diffraction (XRD), Fourier transform IR spectroscopy (FTIR), field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer, Emmett and Teller (BET), and inductively coupled plasma optical emission spectrometry (ICP-OES) to study phase purity, particle morphology, elemental composition, specific surface area and in-vitro ion release. XRD analysis confirmed the formation of pure phase barium doped fluorine-hydroxyapatite with increased lattice parameters but with reduced degree of crystallinity. FESEM analysis confirmed the formation of spherical nanoparticles with homogenous distribution of elements with reduction in crystallite size when compared to HA, while BET results showed an increase in specific surface area upon increased degree of Ba doping. In-vitro bioactivity study carried out in SBF revealed that the incorporation of Ba²⁺ ions into HA structure lead to the faster release of Ca²⁺ ions resulting in faster formation of apatite layer.