Analysing the bioactive makeup of demineralised dentine matrix on bone marrow mesenchymal stem cells for enhanced bone repair

Abstract

Dentine matrix has proposed roles for directing mineralised tissue repair in dentine and bone; however, the range of bioactive components in dentine and specific biological effects on bone-derived mesenchymal stem cells (MSCs) in humans are less well understood. The aims of this study were to further elucidate the biological response of MSCs to demineralised dentine matrix (DDM) in enhancing wound repair responses and ascertain key contributing components. Dentine was obtained from human teeth and DDM proteins solubilised with ethylenediaminetetraacetic acid (EDTA). Bone marrow derived MSCs were commercially obtained. Cells with a more immature phenotype were then selected by preferential fibronectin adhesion (FN-BMMSCs) for use in subsequent in vitro assays. DDM at 10 µg/mL reduced cell expansion, attenuated apoptosis and was the minimal concentration capable of inducing osteoblastic differentiation. Enzyme-linked immunosorbent assay (ELISA) quantification of growth factors indicated physiological levels produced the above responses; transforming growth factor β (TGF-β1) was predominant (15.6 ng/mg DDM), with relatively lower concentrations of BMP-2, FGF, VEGF and PDGF (6.2-4.7 ng/mg DDM). Fractionation of growth factors from other DDM components by heparin affinity chromatography diminished osteogenic responses. Depletion of biglycan from DDM also attenuated osteogenic potency, which was partially rescued by the isolated biglycan. Decorin depletion from DDM had no influence on osteogenic potency. Collectively, these results demonstrate the potential of DDM for the delivery of physiological levels of growth factors for bone repair processes, and substantiate a role for biglycan as an additional adjuvant for driving osteogenic pathways.

Nano-Structured Demineralized Human Dentin Matrix to Enhance Bone and Dental Repair and Regeneration

“…The amount of growth factors was detected by enzyme-linked immunosorbent assay (ELISA). Results showed that TGF-β1 was the most abundant growth factor; BMP-2, FGF-2, VEGF, PDGF and IGF-1 demonstrated intermediate abundance; while BMP-4 and BMP-7 had the lowest concentrations, as shown in Table 1 [32]. DDM proposed osteogenic and dentingenic differentiation of bone mesenchymal stem cells (BMSCs), however, after fractionation of growth factors from DDM by heparin affinity chromatography, the osteogenic responses of BMSCs diminished, indicated that growth factors play significant role in the osteogenesis and dentingenesis of DDM.…”

“…The demineralization process opens the dentin tubules and frees up the growth factors, which can stimulate tissue repair and regeneration. Previous studies demonstrated transforming growth factor β (TGF-β1), bone morphogenetic proteins (BMPs), vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), platelet-derived growth factor (PDGF) and insulin-like growth factor-1 (IGF-1) in DDM [32][33][34][35][36]. The amount of growth factors was detected by enzyme-linked immunosorbent assay (ELISA).…”

Histological Review of Demineralized Dentin Matrix as a Carrier of rhBMP-2

“…35 Among many NCPs preembedded in the dentin inorganic mineral phase, 15,36,37 HD-GFs, including transforming GF b, BMP-2, fibroblast growth factor, vascular endothelial growth factor, platelet-derived GF, BMP-7, and BMP-4, have been extensively studied. 19 BMP-2, BMP-7, and BMP-4 are present in dentin as ED-BMPs.…”

“…This feature could be explained by the observation that dentin and bone are similar in chemical composition and structural organization, both showing collagen and mineral crystal deposition at the micro-and nanometer levels. Moreover, dentin has an absolute number of NCPs, including dentin sialoprotein, osteopontin, dentin matrix protein-1, and matrix extracellular phosphoglycoprotein, 18,19 which are thought to influence cell behavior. 39 For example, osteocytic proteins, which are expressed in bone but not in dentin, may suppress osteoclast formation during the bone remodeling process.…”

“…[14][15][16][17] As a major component of teeth, dentin is an acid-insoluble, acellular, avascularized type I collagenous scaffold with nanoporous dentinal tubules containing minerals and noncollagenous proteins (NCPs), including GFs. 18,19 Among the many human dentin matrix-derived GFs (HD-GFs), endogenous dentin BMPs (ED-BMPs), which are similar to bone matrix-derived BMPs, have been identified and purified, showing similar actions in vivo. 20 The dentin matrix comprises four types of calcium phosphate (e.g., hydroxyapatite, b-tricalcium phosphate, amorphous calcium phosphate, and octacalcium phosphate) with low crystalline apatite, which possess higher solubility.…”