MOF Nanosystem Activated By Caries Microenvironment For Caries Repair

Breaking through the physical barrier of biofilm while repairing caries lesion is the key issue in biomimetic mineralization. We aimed to design a metal organic framework (MOF) nanosystem capable of penetrating biofilm and promoting the remineralization of caries lesions. MOF (Cu-ZIF-8) encapsulated with Glucose oxidase (GOx) was synthesized via aqueous one-step method. Calcium and phosphorus prenucleation clusters (CaP-PNCs) was synthesized using starch template. MOF nanosystem was formed by mixing GOx@Cu-ZIF-8 and CaP-PNCs, then characterized using SEM, TEM, Zeta potentiometer, and EDX. The peroxidase and cascade catalytic activity, bactericidal capability, biocompatibility, and remineralization effect were evaluated using SEM, CLSM, EDS, and CCK8 assay. MOF nanosystem with a particle size of ∼200 nm and negative charge could penetrate bacterial biofilms. MOF nanosystem exhibited peroxidase and GOx activities. Under acidic conditions, it catalyzed the production of H2O2 from glucose and generated reactive oxygen species for bactericidal effects. When cultured with human gingival fibroblasts, this nanosystem demonstrated excellent biocompatibility. In the presence of biofilms, enamel-like crystals were regenerated on the etched enamel surface. EDS analysis indicated that the composition and density of the regenerated crystals were comparable to those of natural enamel. In vivo caries model confirmed that the remineralized layer not only achieved morphological repair but also exhibited favorable mechanical properties. MOF nanosystem could respond to glucose and acidic cariogenic microenvironment, demonstrating superior efficacy in repairing caries. This strategy, activated by caries microenvironment, exhibited significant clinical potential for the prevention and treatment of caries.