Motif-designed peptide nanofibers as bioactive surface modifiers for biomimetic hydroxyapatite formation on demineralized porous dentin

Abstract

Dentin hypersensitivity (DH) is closely associated with mineral loss and subsequent exposure of dentinal tubules, which underscores the need for biomimetic strategies capable of restoring dentin as an organic–inorganic composite. In this work, a short peptide (KLVFFAKMLPHHGA) was designed by integrating a self-assembly motif with a mineralization-inducing segment, aiming to promote dentin remineralization. The peptide readily formed stable nanofibrous assemblies in ethanol containing 0.1% (v/v) trifluoroacetic acid (TFA; TFA : ethanol = 1 : 9) at 37 °C. These peptide nanofibers (PNFs) could be immobilized onto the demineralized dentin surface and acted as organic frameworks for calcium phosphate deposition. After in vitro remineralization under 1.5× simulated body fluid (1.5× SBF), a continuous and dense remineralized layer was gradually formed on the dentin surface. As the mineralization process progressed, mineral deposition extended inward along the dentinal tubules, resulting in effective deep tubule occlusion. Micromorphological observations and compositional analyses further revealed that the newly formed mineral phase exhibited structural and chemical features consistent with an apatite-like calcium phosphate phase. Compared with the control group, dentin treated with PNFs showed an improvement in surface microhardness. Meanwhile, biocompatibility evaluations indicated that the system exhibited favorable biocompatibility under the experimental conditions. Based on these findings, the self-assembling short PNF-mediated biomimetic mineralization strategy proposed in this study provides a facile materials design approach with potential applicability for the remineralization and functional improvement of demineralized dentin.