A bifunctional nanocomplex with remineralizing and antibacterial activities to interrupt dental caries

Dental caries result from an imbalance between the demineralization and remineralization of dental hard tissues, primarily caused by biofilm accumulation. According to the theory of interrupting dental caries, effective anticaries materials and techniques should possess both remineralizing and antibacterial properties. However, current anticaries materials fail to mimic the process of amelogenesis to achieve remineralization while inhibiting the adhesion of cariogenic bacteria and the formation of biofilms. In this study, silk fibroin (SF) loaded with benzalkonium chloride (BZC) successfully formed an SF-BZC composite. This composite stabilized amorphous calcium phosphate (ACP), creating an ACP@SF-BZC dual-functional nanocomplex with both remineralizing and antibacterial properties. ACP@SF-BZC demonstrated significant anti-adhesion and biofilm inhibitory effects against Streptococcus mutans and Streptococcus sobrinus. Moreover, compared to fluoride, ACP@SF-BZC significantly enhanced the remineralization of demineralized enamel surfaces, forming a stable remineralized layer with improved mechanical properties, both in vitro and in vivo. In summary, the dual-function ACP@SF-BZC nanocomplex, with its remineralizing and antibacterial effects, offers a promising alternative for preventing and arresting enamel caries.