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

Abstract

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.