An amyloid-based hydrogel with remineralizing and antibacterial properties for interrupting dental caries.

Dental caries is a multifactorial and dynamic disease primarily mediated by biofilm formation, resulting in a disruption of plaque microecological homeostasis and an imbalance in demineralization/remineralization of dental hard tissues. The development of antibacterial/remineralizing composite materials may help restore this balance. However, anticaries products that can mimic the amelogenesis process to achieve enamel remineralization and possess antimicrobial property are lacking. In this study, bovine serum albumin (BSA)-loaded ethylpyridinium chloride (CPC) was successfully used to form a BSA-CPC complex through H-bonding, van der Waals forces and electrostatic attraction. Subsequently, through fast amyloid-like aggregation, the phase-transitioned BSA (PTB)-CPC stabilized the amorphous calcium phosphate (ACP) to generate an ACP@PTB-CPC hydrogel. Next, 1% sodium hypochlorite (NaClO) was used to partly degrade this hydrogel and induce enamel remineralization. Herein, a biomimetic system of amelogenesis composed of the ACP@PTB-CPC hydrogel and NaClO was constructed, which mimics the gel-like microenvironment of amelogenesis, the amyloid-like structure of amelogenin, and the whole process of the three "key events" in the amelogenesis process. Compared with fluoride, this hydrogel has significant remineralization ability both in vitro and in vivo. Additionally, the application of the ACP@PTB-CPC hydrogel effectively inhibited the growth, adhesion and biofilm formation of Streptococcus mutans. In conclusion, the ACP@PTB-CPC hydrogel with remineralizing and antibacterial properties serves as an alternative therapy for preventing or arresting caries. STATEMENT OF SIGNIFICANCE: 1. Construction of An Amyloid-based Hydrogel: Using PTB as a fundamental framework, CPC was loaded and subsequently coassembled with ACP to obtain an amyloid-based hydrogel--ACP@PTB-CPC. 2. Biomimetic Amelogenesis Process: A biomimetic system of amelogenesis composed of ACP@PTB-CPC hydrogel and NaClO was constructed. 3. Potential for Clinical Application: A bifunctional anticaries material with remineralizing and antibacterial ability was developed, representing a promising alternative therapy of preventing and arresting enamel caries.