Nanocrystalline hydroxyapatite doped with selenium oxyanions: A new material for potential biomedical applications

• We synthesized and analyzed hydroxyapatites doped with selenium oxyanions.
• We used various analytical methods, i.e. XRD, TEM, AAS and FT-IR.
• We confirmed incorporation of SeO32 − and SeO42 − into the crystal lattice.
• The toxicity of the materials was studied.

Selenium-substituted hydroxyapatites containing selenate SeO42 − or selenite SeO32 − ions were synthesized using a wet precipitation method. The selenium content was determined by atomic absorbance spectrometry. The raw, unsintered powders were also characterized using powder X-ray diffraction, middle-range FT-IR spectroscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopic microanalysis. The synthesized apatites were found to be pure and nanocrystalline with a crystal size similar to that in bone mineral. The incorporation of selenium oxyanions into the crystal lattice was confirmed.The toxicity of hydroxyapatites containing selenite or selenate ions was evaluated with a protozoan assay and bacterial luminescence test.