In vitro study of iron doped hydroxyapatite

The effect of iron substitution on the bioactivity of hydroxyapatite (HAp) under the physiological conditions was investigated. Five samples of iron doped hydroxyapatite (FeHAp) with different iron concentrations (0, 0.05, 0.1, 0.2, and 0.3 mol%) were synthesized by wet chemical method. The formation of bone-like apatite layer on the surface of the samples was detected using X-ray diffraction (XRD), Fourier transforms infrared (FTIR) and scanning electron microscope techniques. The changes of the pH of SBF medium were measured at pre-determined time intervals using a pH meter. The dissolution of calcium, phosphorus and iron ions in SBF medium was determined by single beam scanning spectrophotometer. XRD and FTIR results exhibit the formation of carbonate apatite layer on the surface of the immersed samples, which increase with the increase of iron content. SEM results showed agglomeration of small crystals on the surface of the immersed samples. The solubility and dissolution tests revealed that iron doped HAp samples had a higher solubility and dissolution rate than pure sample, which indicated that iron increased the bioactivity of HAp in vitro.