Mineralization of Dense Collagen Hydrogel Scaffolds by Human Pulp Cells
Mineralization of Dense Collagen Hydrogel Scaffolds by Human Pulp Cells
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DOI：
10.1177/0022034513488599
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发表时间：
2013-07-01
影响因子：
7.6
通讯作者：
McKee, M. D.
中科院分区：
文献类型：
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作者：
Coyac, B. R.;Chicatun, F.;McKee, M. D.
尽管近年来生物矿化研究取得了进展，但在骨和牙齿细胞分化、细胞外基质的外向内信号以及蛋白质表达与矿物质沉积之间的联系等方面仍存在未解之谜。在目前的研究中，我们验证了使用生物工程三维（3D）致密胶原水凝胶支架作为细胞培养模型来探索这些问题。将人类脱落乳牙（SHEDs）的牙髓祖细胞/干细胞植入细胞外基质样胶原凝胶中，其纤维密度通过塑料压缩而增加。在24天的培养中，研究了SHED的活力、形态、代谢活性以及支架矿化。此外，碱性磷酸酶酶活性的测量，以及矿化组织细胞标记物ALPL（组织非特异性碱性磷酸酶）、DMP1（牙本质基质蛋白1）和OPN（骨桥蛋白）的免疫印迹，表明致密胶原支架中的成骨/牙源性细胞分化与矿化一致。通过电子衍射和能量色散x射线能谱分析，结合傅里叶变换红外光谱和生化分析，对矿物相进行了分析，发现磷灰石矿物的形成与胶原原纤维排列一致。总之，3D致密胶原支架的使用促进了SHED骨/牙源性细胞的分化和矿化。
While advances in biomineralization have been made in recent years, unanswered questions persist on bone- and tooth-cell differentiation, on outside-in signaling from the extracellular matrix, and on the link between protein expression and mineral deposition. In the present study, we validate the use of a bioengineered three-dimensional (3D) dense collagen hydrogel scaffold as a cell-culture model to explore these questions. Dental pulp progenitor/stem cells from human exfoliated deciduous teeth (SHEDs) were seeded into an extracellular matrix-like collagen gel whose fibrillar density was increased through plastic compression. SHED viability, morphology, and metabolic activity, as well as scaffold mineralization, were investigated over 24 days in culture. Additionally, measurements of alkaline phosphatase enzymatic activity, together with immunoblotting for mineralized tissue cell markers ALPL (tissue-non-specific alkaline phosphatase), DMP1 (dentin matrix protein 1), and OPN (osteopontin), demonstrated osteo/odontogenic cell differentiation in the dense collagen scaffolds coincident with mineralization. Analyses of the mineral phase by electron microscopy, including electron diffraction and energy-dispersive x-ray spectroscopy, combined with Fourier-transform infrared spectroscopy and biochemical analyses, were consistent with the formation of apatitic mineral that was frequently aligned along collagen fibrils. In conclusion, use of a 3D dense collagen scaffold promoted SHED osteo/odontogenic cell differentiation and mineralization.