Amyloid-Like Protein Matrix Composite Occluding Exposed Dentinal Tubules

A biomimetic mineralization strategy is developed to replicate essential biomineralization processes, constructing an organic-inorganic composite matrix for durable dentinal tubules (DTs) occlusion in treating dentin hypersensitivity(DH). Tris(2-carboxyethyl)phosphine (TCEP) stabilized amorphous calcium phosphate(ACP) nanoparticles (ACP@TCEP) were hybridized with PEG-grafted lysozyme (Lyso-PEG) to form amyloid-matrix nanocomplexes (ACP@Lyso-PEG). A series of characterizations confirmed the successful fabrication, followed by in vitro evaluation of DTs occlusion on demineralized dentin via SEM imaging, EDS analysis, and nanoindentation measurements, while in vivo rat oral models simultaneously validated the reparative efficacy. The in vivo and in vitro results indicated that the ACP@lyso-PEG nanocomplexes promoted the rapid occlusion of DTs (5 days). Moreover, peritubular dentine surface, with a crystal depth exceeding 60 μm, which was significantly deeper than most reported values. Elemental mapping and EDS analysis of the sealed DTs, revealing a uniform distribution of Ca and P around the peritubular dentin, with a Ca/P ratio of 1.66. The crystals formed in the restorative layer were enamel like, and their mechanical properties and stability were far superior to those obtained with fluoride treatment applied clinically. In this work, a biomimetic organic-inorganic composite matrix mineralization strategy was proposed. The amyloid-like structure of the composite matrix provides a template for inducing biomineralization, while the introduction of ACP supplies essential mineral components for the remineralization process. This biomimetic strategy offers a promising approach for clinical treatment of DH by effectively occluding DTs.