Cementomimetics—constructing a cementum-like biomineralized microlayer via amelogenin-derived peptides

Abstract

Cementum is the outer-, mineralized-tissue covering the tooth root and an essential part of the system of periodontal tissue that anchors the tooth to the bone. Periodontal disease results from the destructive behavior of the host elicited by an infectious biofilm adhering to the tooth root and left untreated, may lead to tooth loss. We describe a novel protocol for identifying peptide sequences from native proteins with the potential to repair damaged dental tissues by controlling hydroxyapatite biomineralization. Using amelogenin as a case study and a bioinformatics scoring matrix, we identified regions within amelogenin that are shared with a set of hydroxyapatite-binding peptides (HABPs) previously selected by phage display. One 22-amino acid long peptide regions referred to as amelogenin-derived peptide 5 (ADP5) was shown to facilitate cell-free formation of a cementum-like hydroxyapatite mineral layer on demineralized human root dentin that, in turn, supported attachment of periodontal ligament cells in vitro. Our findings have several implications in peptide-assisted mineral formation that mimic biomineralization. By further elaborating the mechanism for protein control over the biomineral formed, we afford new insights into the evolution of protein–mineral interactions. By exploiting small peptide domains of native proteins, our understanding of structure–function relationships of biomineralizing proteins can be extended and these peptides can be utilized to engineer mineral formation. Finally, the cementomimetic layer formed by ADP5 has the potential clinical application to repair diseased root surfaces so as to promote the regeneration of periodontal tissues and thereby reduce the morbidity associated with tooth loss.

Self-Assembly of Filamentous Amelogenin Requires Calcium and Phosphate: From Dimers via Nanoribbons to Fibrils

“…While not widely studied in biomineralization, numerous critical roles are described for histidine-phosphate interactions in kinase biology 57 . A recent study demonstrated biomineral interactions for peptides including the residues proposed here, having been identified by analogous informatic analyses of a predicted amelogenin structure and hydroxyapatite-binding sequences from phage display data evolutionary selection experiments 58 . Specifically, the histidine-rich regions were the only ones to interact with hydroxyapatite, while the acid-rich regions bound strongly to calcium.…”

Protein-mediated hydroxyapatite composite layer formation on nanotubular titania

“…The HA-binding peptide, HABP1, selected using combinatorial techniques 34,42,52,71 with a seven amino acid sequence had previously been shown to act as a mineralisation regulator by interacting with its nano-environment enabling the specific polypeptide-mineral interaction. 51,52 We then conjugated this peptide to a fluorescence protein and designed the GFPuv-HABP1.…”

“…[32][33][34][35] Mimicking these natural systems, innovative nanomaterials have been developed using various deposition methods including mineral coatings. [27][28][29][30][31][36][37][38][39][40][41][42][43] Recently, biological materials with nanostructured topography have been developed with controlled and arranged surface porosity from macro to nanoscale, 44 that is, from the macroscale of titanium metal, maintaining bone integrity, down to the micro-nanoporous metal-oxide level interdigitating the implant with the bone tissue, to the nanocrystalline bioactive mineral layer enabling bone regeneration by the bone forming cells of the body. 45 The metal oxide-tissue interface can be enriched with the use of biomolecules that can undertake an interfacial role.…”

Accelerated Nucleation of Hydroxyapatite Using an Engineered Hydrophobin Fusion Protein

“…In the past, many research groups have focused on the in vitro synthesis of enamel. 1,[3][4][5][6][7][8][9][10][11][12] Protein or peptide mediated biomineralization has been found to be a promising method to reconstruct enamel because it can occur under physiological conditions to provide a biocompatible material. Detailed studies of extracellular matrix proteins during the development of enamel or dentin have led to a deeper understanding of the biomineralization process of teeth.…”