Synthesis and antibacterial evaluation of calcinated Ag-doped nano-hydroxyapatite with dispersibility.

PurposeDispersible hydroxyapatite (HAp) nanoparticles are very useful for applying a monolayer to implantable medical devices using the nano-coating technique. To improve tolerance to infection on implanted medical devices, silver-doped HAp (Ag-HAp) nanoparticles with dispersiblity and crystallinity were synthesized, avoiding calcination-induced sintering, and evaluated for antibacterial activity.MethodsThe Ca10-xAgx(PO4)6(OH)2 with x = 0 and 0.2 were prepared by wet chemical processing at 100°C. Before calcination at 700°C for 2 h, two kinds of anti-sintering agents, namely a Ca(NO3)2 (Ca salt) and a poly-acrylic acid/Ca salt mixture (PAA-Ca), were used. Escherichia coli was used to evaluate the antibacterial activity of the nanopowder.ResultsWhen PAA-Ca was used as an anti-sintering agent in calcination to prepare the dispersible nanoparticles, strong metallic Ag peaks were observed at 38.1° and 44.3° (20) in the X-ray diffraction (XRD) profile. However, the Ag peak was barely observed when Ca salt was ...