TiO2/SiO2-NHOC-FA Nanocomposite as a Photosensitizer with Targeting Ability for Photocatalytic Killing MCF-7 Cells in Vitro and its Mechanism Exploration

In the paper, a composite TiO 2 /SiO 2 -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 TiO 2 /SiO 2 -NHOC-FA composite is 18 nm, which is spherical. Compared with unmodified TiO 2 , TiO 2 /SiO 2 -NHOC-FA composite had superior water solubility and dispersion, and enhanced its photokilling activity by folic acid-targeted to FR (+) cells. In addition, photocatalytic TiO 2 /SiO 2 -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 TiO 2 /SiO 2 -NHOC-FA composite can provide a theoretical basis for the photodynamic development of TiO 2 .