In the paper, a composite TiO2 /SiO2 -NHOC-FA was prepared using the coupling method which is a folic acid-targeted silica-coated titanium dioxide. Their structures were characterized by Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction (XRD), Transmission electron microscope (TEM) and Zeta potential method. The results showed that the average diameter of the prepared TiO2 /SiO2 -NHOC-FA composite is 18 nm, which is spherical. Compared with unmodified TiO2 , TiO2 /SiO2 -NHOC-FA composite had superior water solubility and dispersion, and enhanced its photokilling activity by folic acid-targeted to FR (+) cells. In addition, photocatalytic TiO2 /SiO2 -NHOC-FA arrested cell cycle in G2/M phase of MCF-7 cells, resulting in a significant reduction of mitochondrial membrane potential (MMP), and also made the apoptosis rate, ROS components and intracellular calcium concentration increased. It killed the MCF-7 cells through apoptosis pathway. These results for the TiO2 /SiO2 -NHOC-FA composite can provide a theoretical basis for the photodynamic development of TiO2 .

中文翻译：

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TiO 2 /SiO 2 -NHOC-FA纳米复合材料作为具有靶向能力的光催化体外杀伤MCF-7细胞的光敏剂及其机制探索

本文采用偶联法制备了复合TiO2/SiO2-NHOC-FA，即叶酸靶向二氧化硅包覆的二氧化钛。通过傅里叶变换红外光谱(FT-IR)、紫外-可见光谱(UV-vis)、X射线衍射(XRD)、透射电子显微镜(TEM)和Zeta电位法对其结构进行了表征。结果表明,制备的TiO2/SiO2-NHOC-FA复合材料的平均粒径为18 nm,呈球形。与未改性的 TiO2 相比，TiO2 /SiO2 -NHOC-FA 复合材料具有优异的水溶性和分散性，并且通过叶酸靶向 FR (+) 细胞增强了其光杀伤活性。此外，光催化 TiO2 /SiO2 -NHOC-FA 在 MCF-7 细胞的 G2/M 期阻滞细胞周期，导致线粒体膜电位 (MMP) 显着降低，也使细胞凋亡率、ROS成分和细胞内钙浓度增加。它通过凋亡途径杀死MCF-7细胞。TiO2/SiO2-NHOC-FA复合材料的这些结果可以为TiO2的光动力学发展提供理论依据。