Novel gallium-doped amorphous calcium phosphate nanoparticles: Preparation, application and structure study

Novel gallium-doped amorphous calcium phosphate (ACP) nanoparticles with different (Ga + Ca)/P molar ratio (1.8-3.0) were synthesized using sol-gel method. The antibacterial effects of the gallium-doped ACP samples were tested using disk diffusion assays, against Pseudomonas aeruginosa. The results showed that the gallium-doped ACP samples have obvious effect of inhibiting the growth of Pseudomonas aeruginosa and could have a long term antibacterial properties. The local structures of these amorphous calcium phosphate nanoparticles were studied by 31P, 71Ga single pulse, double-resonance and 31P homonuclear dipolar recoupling solid state NMR techniques. The solid state NMR studies indicate that gallium-doped ACP nanoparticles are consisted of Gax(OH)yOz and calcium phosphate clusters. Gallium-doped ACP nanoparticles could be promising complex materials with the properties of antibacterial and biological mineralization.