Polydopamine Promotes Dentin Remineralization via Interfacial Control

Biomineralization has intrigued researchers for decades. Although mineralization of type I collagen has been universally investigated, this process remains a great challenge due to the lack of mechanistic understanding of the roles of biomolecules. In our study, dentine was successfully repaired using the biomolecule polydopamine (PDA), and the remineralized dentine exhibited mechanical properties comparable to those of natural dentine. Detailed analyses of the collagen mineralization process facilitated by PDA showed that PDA can promote intrafibrillar mineralization with a decreased heterogeneous nucleation barrier for hydroxyapatite (HAP) by reducing the interfacial energy between collagen fibrils and amorphous calcium phosphate (ACP), resulting in the conversion of an increasing amount of nanoprecursors into collagen fibrils. The present work highlights the importance of interfacial control in dentine remineralization and provides profound insight into the regulatory effect of biomolecules in collagen mineralization as well as the clinical application of dentine restoration.