A MOF‐based Core–Shell System Enables Controlled Release and Ordered Assembly of Nano‐Hydroxyapatite for Enamel Remineralization

Abstract Enamel demineralization is a prevalent complication during orthodontic treatment, necessitating effective interventions to restore tooth function and prevent caries progression. While in situ enamel remineralization emerges as a promising therapeutic approach, the regeneration of enamel‐like structures remains a significant challenge. Herein, a controlled‐release system based on a ZIF‐8@nHA core–shell architecture is proposed for targeted enamel remineralization. The gradual degradation of ZIF‐8 metal‐organic framework (MOF) in saliva facilitates the controlled release of encapsulated nano‐hydroxyapatite (nHA) agents, preventing their disorganized aggregation during crystal assembly. Furthermore, liberated 2‐methylimidazole molecules direct epitaxial alignment and oriented assembly of nHA on the enamel surface. Leveraging these merits, ZIF‐8@nHA enables the formation of a well‐aligned remineralization layer, replicating both microstructure and mechanical strength of natural enamel. Moreover, ZIF‐8@nHA is amenable to a facile one‐step synthesis with economic viability, and can be easily coated onto invisible orthodontic appliances (ZIF‐8@nHA@OA), demonstrating exceptional potential for addressing orthodontic‐induced enamel demineralization.