Self-Assembled Photothermal Particles Boost Synergistic Biofilm Eradication and Remineralization in Early Dental Caries Treatment.

Abstract

Dental caries, driven by dietary habits and microbial biofilms, remains a significant global health issue. In situ biomimetic remineralization is considered a promising method, but its low efficiency is a key challenge. Additionally, the interference of cariogenic bacteria further exacerbates the problem. In this study, self-assembled photothermal particles (PAEB) with light-boosted synergistic biofilm eradication and remineralization properties for caries treatment are reported. Composed by polyaspartic acid-stabilized amorphous calcium phosphate (Pasp-ACP) and ε-poly-L-lysine/baicalein (EPL-BC), PAEB enable efficient light-to-heat conversion under near-infrared light exposure due to polymerization and stacking of baicalein. The localized hyperthermia, accompanied with EPL-BC disrupts bacterial membranes and eradicates biofilm by more than 99%, which is seven times higher than the non-radiation group (12.86%) and ≈21 times higher than the fluoride group (4.35%). Meanwhile, the releasing of calcium and phosphate ions is accelerated for rapid remineralization, with highest hardness recovery (1.96 GPa) of all groups, comparable to untreated healthy enamel. Moreover, in vivo microbiome analysis confirms that PAEB selectively reduces the abundance of cariogenic Streptococcus spp. while maintaining overall microbial diversity and oral ecological balance, presenting a promising solution for non-invasive dental caries treatment. This photothermal-enhanced strategy gives a reference for the design of bioactive therapeutic dental materials.