In situ remineralizaiton of partially demineralized human dentine mediated by a biomimetic non-collagen peptide

Abstract

Biomineralization is a well-regulated process mediated by many extracellular matrix proteins. Some collagenous proteins act as frameworks for depositing minerals in a preferred orientation while non-collagenous proteins (BSP, BPP, OC, etc.) function as regulators of the mineralization process, either as nuclei or inhibitors of hydroxyapatite. Biomimetic remineralization strategies should reproduce the dimension and structural hierarchy of apatite within a collagen matrix. Here we synthesized a peptide with sequence (EEEEEEEEDS_pES_pS_pEEDR) mimicking the function of BSP and DMP1 as calcium phosphate- and collagen-binding matrix protein analogues. More metastable calcium phosphate nanoprecursors were combined with the collagen matrix in acid-demineralized dentine pre-incubated with peptides during the process of remineralization in the phosphate-containing fluid. With the presence of our synthetic peptides, these nanoprecursors were transformed into polyelectrolyte-stabilized apatite nanocrystals that assembled at the “hole zones” (gap remineralization) and along the surface of the dentine collagen fibrils (surface remineralization). The transition from nanocrystals to larger apatite platelets was promoted by synthetic peptidesvia the formation of mesocrystal intermediates. It was concluded that deliberately designed peptide (EEEEEEEEDS_pES_pS_pEEDR) improved in situ remineralization of acid-etched dentine.