Shou Guohui, Lin Suya, Shen Shuxian, He Xuzhao, Dong Lingqing, Cheng Kui, Weng Wenjian
School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China.
The Stomatologic Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China.
ACS Biomater Sci Eng. 2019 Jul 8;5(7):3352-3360. doi: 10.1021/acsbiomaterials.9b00679. Epub 2019 Jun 20.
Cell responses to oxide biomaterials depend on the protein adsorption behavior of the biomaterial surface. Thus, the inherent properties of oxide biomaterial surfaces play a key role in this process. However, commonly used biomaterials, such as calcium phosphate and titanium dioxide, have surfaces with strong mineralization, which may interfere with the ability to clarify the key aspects of the oxide biomaterial regarding protein adsorption and cellular processes. Here, nonmineralized crystalline and vitreous silica were selected as model oxide biomaterials to explore the inherent properties of these materials on the absorption behavior of the functional protein fibronectin (Fn) and on the osteogenic differentiation of mesenchymal stem cells (MSCs). We demonstrated that due to the smaller O binding energy, the weaker polarization of oxygen atoms in vitreous silica produced a greater amount of acidic hydroxyls after hydration compared to crystalline silica. These distinct features significantly upregulated the exposure of arginylglycylaspartic acid (RGD) and synergy sites (PHSRN) of Fn and eventually enhanced the osteogenic differentiation of MSCs on vitreous silica surfaces through activation of the integrin-linked kinase (ILK) signaling pathway. Our results highlight the key role of inherent oxide biomaterial crystallinity in protein adsorption and cell behavior.
细胞对氧化物生物材料的反应取决于生物材料表面的蛋白质吸附行为。因此，氧化物生物材料表面的固有特性在这一过程中起着关键作用。然而，常用的生物材料，如磷酸钙和二氧化钛，其表面具有很强的矿化作用，这可能会干扰阐明氧化物生物材料在蛋白质吸附和细胞过程方面的关键特性。在此，选择非矿化的结晶态和玻璃态二氧化硅作为氧化物生物材料模型，以探究这些材料对功能蛋白纤连蛋白（Fn）吸附行为以及对间充质干细胞（MSCs）成骨分化的固有特性。我们证明，由于玻璃态二氧化硅中氧结合能较小，与结晶态二氧化硅相比，其在水化后氧原子的极化较弱，产生了更多的酸性羟基。这些独特特性显著上调了Fn的精氨酰甘氨酰天冬氨酸（RGD）和协同位点（PHSRN）的暴露，并最终通过激活整合素连接激酶（ILK）信号通路增强了MSCs在玻璃态二氧化硅表面的成骨分化。我们的结果突出了氧化物生物材料固有结晶度在蛋白质吸附和细胞行为中的关键作用。
