Objective:To prepare nanosilver-hybridized polylactic acid-glycolic acid copolymer (PLGA) microspheres loaded with simvastatin (SIM), and to evaluate its sustained release effect in vitro. Methods:The emulsification-solvent evaporation method was used to prepare SIM-loaded PLGA microspheres. Silk fibroin (SF) was used to modify the surface of SIM-loaded PLGA microspheres by hydrophobic interaction. Then, the microspheres were continually modified by electrostatic adsorption to chitosan (CTS) and nano-silver (AgNPs) to prepare SF-AgNPs-CTS-SF-SIM-PLGA microspheres. Scanning electron microscope, Fourier transform infrared spectrometer, energy spectrometer, Zeta potential meter were used to analyze the SIM-loaded microspheres. The external release properties of the SIM-loaded microspheres were also investigated.Results:The average diameter of the prepared PLGA microspheres was about 9.67 μm. The results of Fourier transform infrared spectroscopy and energy spectroscopy showed that the AgNPs-CTS-SF-SIM-PLGA microspheres have been successfully constructed. The Zeta potential results indicated that the SIM-loaded microspheres were all in a stable state. The in vitro release results showed that the SF-AgNPs-CTS-SF-SIM-PLGA microspheres had a good in vitro release effect, could delay the drug release rate and prolong the drug release time. Conclusions:The SF-AgNPs-CTS-SF-SIM-PLGA microspheres have antibacterial and osteogenic effects, and exhibit a good in vitro release effect. They can be used for local sustained-release administration in the oral cavity, which make makes them potentially useful in the treatment of periodontitis.