Nitrosothiol-functionalized silicate bioceramic scaffolds with enhanced antibacterial property for bone repair

Abstract

Bacterial infection is a challenge in the field of bone tissue engineering. Antibiotics are often used to combat infection, but the abuse of antibiotics causes nonselective cytotoxicity and induces bacterial drug resistance. Therefore, it is of great clinical significance to develop bone tissue engineering scaffolds with antibacterial properties for bone repair. In this study, polymer-derived β-Ca2SiO4 (C2S) scaffolds were functionalized with nitric oxide (NO) precursors to repair infected bone defects due to their synergistic antibacterial properties by combining a photothermal effect and NO gas therapy. The results showed that the functionalization of C2S scaffolds with NO precursors not only maintained the initial macropore structure and photothermal effect of the scaffolds, but also endowed the scaffolds with sustained NO release ability. Importantly, the NO precursor-functionalized C2S (C2S–SNO) scaffolds improved the proliferation and alkaline phosphatase (ALP) activity of bone marrow mesenchymal stem cells (rBMSCs), as well as the expression of related osteogenic genes. Furthermore, the photothermal effect of the C2S–SNO scaffolds and the NO release induced by near-infrared (NIR) laser irradiation contributed to enhanced antibacterial efficacy, and the inhibition efficiencies of the C2S–SNO scaffolds against Staphylococcus aureus and Escherichia coli were estimated to be approximately 83.3% and 87.5%, respectively. Therefore, the C2S–SNO scaffolds are promising for repairing infected bone defects.