Synthesis and structural characterization of nanoapatite ceramics powders for biomedical applications

Zn/HAp particles were prepared by soaking hydroxyapatite (HAp), derived through a wet chemical method, into aqueous solutions containing various amounts of zinc nitrate. Obtained samples were characterized by inductively coupled plasma emission spectroscopy, X-ray diffraction (XRD), Brunauer-Emmett-Teller surface area analysis (SA), and transmission electron microscopy. Their zeta potential was also measured. The analyzed Zn content was almost proportional to the content in the aqueous solutions. The Zn ²⁺ ions were partially replaced the Ca ²⁺ ions in the apatite, and hence, little change was observed in crystallinity, particle size and SA. Adsorption of bovine serum albumin (BSA) and ß ₂-microglobulin (ß ₂-MG) in the solutions containing both BSA and ß ₂-MG was examined. As the Zn ²⁺ ion content in the apatites increased, the adsorbed amount of BSA was almost constant, whereas that of ß ₂-MG increased. Thus, the Zn incorporation increased the selectivity, and it is suggested that the Zn-substituted site should be the active ones for ß ₂-MG adsorption.