Synthesis of silver modified hydroxyapatite nanoparticle and evaluation of its biological properties in vitro for potential biomedical application

In order to impart nano hydroxyapatite (HA) more biological functions and develop its potential application in biomedical field, silver modified hydroxyapatite (Ag-HA) nanoparticles were synthesized via sol–gel method. The powders were sintered at 600 °C for 1 h. The microstructures, morphologies and chemical compositions of HA and Ag-HA were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), High resolution transmission electron microscopy (HR-TEM), Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDS). The results indicate that Ag modification has a certain effect on the microstructure, morphology and Zeta potential of HA. The hemocompatibility of HA and Ag-HA with different doses were evaluated by lots of hemolytic tests. The results indicate that pure HA performs non-hemolytic activity at the dose range of 20–2000 µg/cm3. Due to the appearance of Ag, the hemocompatibility of Ag-HA with different Ag concentration show obvious differences. The Ag-HA with concentration of 0.5 mol % Ag (0.5Ag-HA) has better hemocompatibility, its hemolytic ratio is less than 5 % when its usage dose is up to 1000 µg/cm3. But Ag-HA with concentration of 1.0 mol % and 1.5 mol % Ag (1.0Ag-HA and 1.5Ag-HA) show non-hemolytic property only lower doses. The antibacterial ratio of 0.5Ag-HA against Streptococcus mutans is up to 99 % only the dose of 400 µg/cm3. The biological evaluation further confirmed the safe dose of the antibacterial HA nanoparticles for its application in biomedical field.