Department of Materials Science and Technology, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka, Niigata 940-2188, Japan.
J Mater Chem B. 2020 Feb 21;8(7):1524-1537. doi: 10.1039/c9tb02534k. Epub 2020 Jan 31.
We synthesized nanostructured mesoporous silica (MS)/hydroxyapatite (HA) hybrid particles in the presence of amphiphilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEOPPOPEO) triblock copolymer (P123). The particles exhibited slit-shaped mesostructures and underwent hybridization reaction between the MS and HA phases containing P123. Furthermore, the aggregated form of the particles exhibited dispersion stability in water in the monodispersed state (average particle size: 145 nm and coefficient of variation: 4.3% in the case of the maximum added amount of P123). Then, the structures of the hydration layer and the adsorbed protein on the particles were investigated to understand the effect of the hydration layer structures on the protein secondary structures. The ratio of the bonding water (intermediate and nonfreezing water) to free water increased upon hybridization, and it decreased with increasing P123 concentration. Upon hybridization, the component ratio of the asymmetric O-H stretching vibration between free water molecules decreased, and that of the symmetric O-H stretching vibration of intermediate water molecules increased. With increasing P123 concentration, the asymmetric O-H stretching vibration between free water molecules increased and the symmetric O-H stretching vibration of intermediate water molecules decreased. It was found that the protein native state component ratios of α-helix and β-sheet increased with increasing symmetric O-H stretching vibration between intermediate water molecules, and they decreased with decreasing asymmetric O-H stretching vibration between free water molecules. Moreover, the cytotoxicity against osteoblasts (MC3T3-E1) was evaluated and the hybrid particles exhibited a high cell density, indicating their bioactivity. On the hybrid particles interacting with P123, the cells were three-dimensionally assembled and uniaxially grown with the culture. Therefore, this is the first successful report of the synthesis of nanostructured MS/HA hybrid particles interacting with P123, and the controlled hydration layer structures on the particle surfaces were found to contribute to the protein secondary structures, promoting cytocompatibility.
我们在两亲性聚（环氧乙烷）-聚（环氧丙烷）-聚（环氧乙烷）（PEOPPOPEO）三嵌段共聚物（P123）的存在下合成了纳米结构介孔二氧化硅（MS）/羟基磷灰石（HA）杂化粒子。这些粒子表现出狭缝型介孔结构，并在含有 P123 的 MS 和 HA 相之间发生了杂交反应。此外，粒子的聚集形式在水中以单分散状态表现出分散稳定性（在 P123 的最大添加量的情况下，平均粒径为 145nm，变异系数为 4.3%）。然后，研究了粒子上水化层和吸附蛋白质的结构，以了解水化层结构对蛋白质二级结构的影响。杂交后，结合水（中间和非冻结水）与自由水的比例增加，而随着 P123 浓度的增加而降低。杂交后，自由水分子之间不对称 O-H 伸缩振动的组分比降低，而中间水分子的对称 O-H 伸缩振动的组分比增加。随着 P123 浓度的增加，自由水分子之间不对称 O-H 伸缩振动增加，中间水分子的对称 O-H 伸缩振动减少。结果发现，随着中间水分子之间对称 O-H 伸缩振动的增加，蛋白质天然状态的α-螺旋和β-折叠组分比增加，而随着自由水分子之间不对称 O-H 伸缩振动的减少，它们减少。此外，还评估了对成骨细胞（MC3T3-E1）的细胞毒性，杂化粒子表现出高细胞密度，表明其生物活性。在与 P123 相互作用的杂化粒子上，细胞在培养过程中进行了三维组装和单轴生长。因此，这是首次成功报道与 P123 相互作用的纳米结构 MS/HA 杂化粒子的合成，并且发现粒子表面上受控的水化层结构有助于蛋白质二级结构，促进细胞相容性。
