Mesoporous silica nanoparticles/gelatin porous composite scaffolds with localized and sustained release of vancomycin for treatment of infected bone defects.

Treatment of infected bone defects still remains a formidable clinical challenge, the design of bone implants with the controlled release of antibiotics is now regarded as a powerful strategy for infection control and bone healing. In this study, we fabricated a composite scaffold based on vancomycin (Van) loaded mesoporous silica nanoparticles (Van@MSNs) and a gelatin matrix. The microscopic structure of the gelatin-based composite scaffolds was characterized as highly porous. By the addition of MSNs, an enhancement in the compression property of MSNs-incorporated composite scaffolds was observed. The Van could release from the Van@MSNs incorporated composite scaffold in a sustained-release manner with a minimal burst, and thus effectively inhibit the growth of Staphylococcus aureus in a subsequent in vitro antibacterial study. In addition, the drug-loaded composite scaffold showed no unfavorable effects on the proliferation and differentiation of bone mesenchymal stem cells (BMSCs), confirming good biocompatibility. Moreover, in vivo results demonstrated that the antibiotic-loaded composite scaffold could significantly reduce bacterial contamination while promoting bone healing. Thus, our results suggest that the fabricated Van@MSNs/Gelatin composite scaffold with a localized and sustained release of antibiotics is a promising biomaterial for treating infected bone defects.