Peptide-mediated route to biomimetic collagen intrafibrillar mineralization

Abstract

Overcoming short lifespan of current dental adhesives remain a significant clinical need. Adhesives rely on formation of hybrid layer to adhere to dentin, and penetrate within collagen fibrils. Achieving complete enclosure of demineralized collagen fibrils by monomers to fill in and close spaces is recognized as unattainable. We developed a peptide-based approach enabling collagen intrafibrillar mineralization and tested our hypothesis on a type-I collagen-based platform. Peptide design incorporated collagen binding and remineralization mediating properties using domain structure conservation approach. The structural changes from representative members of different peptide clusters were generated for each functional domain. Common signatures associated with secondary structure features and the related changes in the functional domain were investigated by the attenuated total reflectance Fourier-transform infrared (ATR-FTIR) and circular dichroism (CD) spectroscopy, respectively. Assembly and remineralization properties of the peptides on the collagen platforms were studied using atomic force microscopy (AFM). Mechanical properties of the collagen fibrils remineralized by the peptide assemblies was studied using PeakForce-Quantiative Nanomechanics (PF-QNM)-AFM. Engineered peptide was demonstrated to offer a promising route for collagen intrafibrillar remineralization. Proposed approach offers a platform to develop multifunctional strategies including different bioactive peptides, polymerizable peptide monomers and adhesive formulations as a step towards improving long-term prospects of composite resins.