Mineralization induction effects of osteopontin, bone sialoprotein, and dentin phosphoprotein on a biomimetic collagen substrate

Abstract

Native bone tissue is composed of a matrix of collagen, non-collagenous proteins, and calcium phosphate minerals, which are primarily hydroxyapatite (HA). The SIBLING (small integrin-binding ligand, N-linked glycoprotein) family of proteins is the primary non-collagenous protein group found in mineralized tissues. In this work, the mineralization induction capabilities of three of the SIBLING members, bone sialoprotein (BSP), osteopontin (OPN), and the calcium binding subdomain of dentin sialophosphoprotein, dentin phosphoprotein (DPP), are directly compared on a biomimetic collagen substrate. A self-assembled, loosely aligned collagen fibril substrate was prepared and then 125I radiolabeled adsorption isotherms were developed for BSP, OPN, and DPP. The results showed that BSP exhibited the highest binding capacity for collagen at lower concentrations, followed by DPP and OPN. However, at the highest concentrations all three proteins had similar adsorption levels. The adsorption isotherms were then used to identify conditions that resulted in identical amounts of adsorbed protein. These substrates were prepared and placed in simulated body fluid for 5 hours, 10 hours, and 24 hours at 37°C. The resulting mineral morphology was assessed by atomic force microscopy and the composition was determined using photochemical assays. Mineralization was seen in the presence of all of the proteins. However, DPP was seen to be the only protein that formed individual mineral nodules similar to those seen in developing bone. This suggests that DPP plays a significant role in the biomineralization process and that the incorporation of DPP into tissue engineering constructs may facilitate the induction of biomimetic mineral formation.

Ex vivo detection and characterization of remineralized carious dentin, by nanoindentation and single point Raman spectroscopy, after amalgam restoration

“…4C·II). This finding is consistent with fibrils containing intrafibrillar and extrafibrillar mineral [49,50] . Collagen regulates mineralization, and a single mutation on a gen that encodes for an α-chain can be responsible for osteogenesis imperfect and dentinogenesis imperfect type I [34] .…”

On modeling and nanoanalysis of caries-affected dentin surfaces restored with Zn-containing amalgam and in vitro oral function

“…This typical staggered pattern of collagen fibrils (Figs 9·bI, 9·cII) was not visible in the partially demineralized dentin of CAD (Fig 9a), but was evident when this substrate became clearly remineralized (Fig 9c). This finding is consistent with fibrils containing intrafibrillar or extrafibrillar mineral 61,63 .…”

Synergistic Inhibition of Enamel Demineralization by Peptide 8DSS and Fluoride

“…The loss or mutation of the DPP gene in humans and mice is associated with mineralization defects in dentin and bone [Prasad et al, 2010], leading to suggestions that the protein plays a significant role in biomineralization. This led to the proposal that incorporating DPP into engineered tissue may help induce biomimetic mineral formation [Zurick et al, 2013]. Indeed, human DPP has been shown to induce dentin mineralization when tightly combined with certain supports [Luo et al, 2003].…”