Vo Tiffany N, Tatara Alexander M, Santoro Marco, van den Beucken Jeroen J J P, Leeuwenburgh Sander C G, Jansen John A, Mikos Antonios G
Department of Bioengineering, Rice University, P.O. Box 1892, MS 142, Houston, Texas, 77251-1892.
Department of Chemical and Biomolecular Engineering, Rice University, P.O. Box 1892, MS 362, Houston, Texas, 77251-1892.
J Biomed Mater Res A. 2017 Jan;105(1):110-117. doi: 10.1002/jbm.a.35875. Epub 2016 Sep 21.
This study sought to characterize the composition and morphology of acellular mineralization occurring in thermally and chemically gelable hydrogels comprising copolymers of hydrophobic N-isopropylacrylamide as a function of hydrogel hydrophobicity and culture medium formulation. The deposition of calcium phosphate (CaP) mineral was hypothesized to occur with increasing hydrogel hydrophobicity and presence of serum proteins in the culture medium. Two hydrogel compositions with a solid content of 15 and 20 wt % were examined in serum-containing and nonserum-containing media for 0, 14, 28, and 56 days. Using biochemical assays, calcium, but not phosphate content, was found to significantly increase over time in hydrophobic hydrogels soaked in cell culture medium with fetal bovine serum. Significant increases in the calcium to phosphate ratio were observed within these hydrogels from day 0 to 56, with mineralization indicated by von Kossa histological staining. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) were used to analyze CaP mineral characteristics. No crystalline apatitic reflection peaks were observed using XRD, which was supported by the lack of observable mineral deposits as observed using SEM/EDX. However, FTIR showed the presence of new absorption peaks in the serum-containing samples at 28 and 56 days which suggested the formation of an immature apatitic-like mineral. The ability to undergo hydrophobicity-dependent and protein-mediated mineralization demonstrates the potential of these dual-gelling hydrogels as acellular self-mineralizing materials for bone tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 110-117, 2017.
本研究旨在表征在由疏水性N-异丙基丙烯酰胺共聚物组成的热凝胶化和化学凝胶化水凝胶中发生的无细胞矿化的组成和形态，该矿化是水凝胶疏水性和培养基配方的函数。据推测，磷酸钙（CaP）矿物质的沉积会随着水凝胶疏水性的增加和培养基中血清蛋白的存在而发生。在含血清和不含血清的培养基中，对两种固体含量分别为15 wt%和20 wt%的水凝胶组合物进行了0、14、28和56天的检测。通过生化分析发现，浸泡在含有胎牛血清的细胞培养基中的疏水性水凝胶中，钙含量随时间显著增加，但磷含量没有增加。在这些水凝胶中，从第0天到第56天观察到钙磷比显著增加，通过冯科萨组织学染色表明发生了矿化。使用X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）和扫描电子显微镜/能量色散X射线光谱（SEM/EDX）分析CaP矿物质特征。使用XRD未观察到结晶磷灰石反射峰，这得到了SEM/EDX观察到缺乏可观察到的矿物质沉积的支持。然而，FTIR显示在含血清样品中，在第28天和第56天出现了新的吸收峰，这表明形成了一种不成熟的类磷灰石矿物质。这些双凝胶化水凝胶具有进行疏水性依赖和蛋白质介导矿化的能力，证明了其作为骨组织工程无细胞自矿化材料的潜力。© 2016威利期刊公司。《生物医学材料研究杂志》A部分：105A：110 - 117，2017。
