Abstract: Objective　 To prepare the drug delivery system of mesoporous silica coated Au Nanobipyramids(Au NBPs@SiO2), and evaluate its characterization, biocompatibility, drug loading, near-infrared responsive property and antibacterial properties. Methods　 The Au Nanobipyramids (Au NBPs) were synthesized by a seed-mediated method, and coated with mesoporous silica (MSNs). It was characterized by scanning electron microscopy, transmission electron microscopy and ultraviolet spectrophotometer, and its biocompatibility was tested by MTT assay. Then, to investigate the Near-Infrared responsive drug release behavior. Finally, the antibacterial properties was evaluated by using E.coli. Results　The drug delivery system of Au NBPs@SiO2 was successfully prepared. The disordered pore structure was observed under transmission electron microscope. And it had no obvious effect on cell proliferation. The loading efficiency reached 76.5%, and the cumulative drug release increased by 41.7% under NIR irradiation. In vitro antibacterial experiments showed it had significantly antibacterial effects. Conclusions　 The drug delivery system of Au NBPs@SiO2 had good biocompatibility, near-infrared responsive drug release behavior and antibacterial properties, and had potential application in periodontal sustained-release antibacterial therapy.

Key words: periodontitis, Au nanobipyramids, mesoporous silica, nearinfrared responsive, antibacterial property