Layer-by-layer coated probiotics with tannic acid-Ca²⁺ and casein phosphopeptide complexes for caries prevention and enamel remineralization

Dental caries is a common disease resulting from tooth demineralization caused by bacterial plaque. Probiotics have shown great potential against caries by regulating the balance of oral flora. However, obstacles such as poor colonization and lysozyme sensitivity in oral cavity hinder their further application. In this study, an efficient layer-by-layer surface coating of tannic acid (TA)-Ca²⁺ and casein phosphopeptide (CPP) was applied to the probiotic Bifidobacterium infantis (BI) with potential anti-caries activity. Multi-functionalized probiotics thus prepared (called BI@TA-Ca²⁺@CPP) exhibited similar growth pattern, resistance to lysozyme and enhanced colonization potential. The ability of BI@TA-Ca²⁺@CPP in inhibiting cariogenic biofilm formation was improved. Moreover, BI@TA-Ca²⁺@CPP showed excellent remineralization efficacy. In a caries-induced rat model, BI@TA-Ca²⁺@CPP significantly prevented the occurrence and progression of tooth decay, meanwhile showing good biocompatibility. In summary, this study underlines the importance of probiotics coating in antibiofilm and remineralization activity as a promising strategy against dental caries.