SiO2@Cu7S4 Nanotube for Photo/Chemodynamic and Photothermal Dual-mode Synergistic Therapy under 808 nm Laser Irradiation
Photodynamic therapy (PDT) is a light-based modality for tumor treatment that involves the generation of reactive oxygen species (ROS) by the combination of light, a photosensitizer, and molecular oxygen. Nevertheless, the therapeutic effects of PDT are limited by hypoxic conditions that worsen with oxygen consumption during the PDT process. Photo/chemodynamic therapy (PCDT) based on the Fenton reaction is one strategy to improve ROS generation, providing that a highly effective Fenton reagent is developed. In this research, SiO2@Cu7S4 nanotube (NT) was synthesized as a PCDT agent. This double-valence metal-sulfide composite material can react with the H2O2 cycle at the tumor site. SiO2@Cu7S4 NT can produce more ROS than the traditional PDT agent, and besides, it can also be used as a photothermal therapy (PTT) agent. SiO2@Cu7S4 NT will trigger the PTT effect under 808 nm irradiation and generate high heat to eradicate cancer cells. This heat will also promote the PCDT effect by increasing the reaction rate. Thus, SiO2@Cu7S4 NT is a suitable material for PCDT and PTT synergistic oncotherapy. The 808 nm laser is selected as the appropriate excitation source, providing adequate penetration and minimal harm to normal cells. The experimental data presented herein demonstrate the promising photosensitive, Fenton-like, and photothermal performance of SiO2@Cu7S4 NT. Furthermore, the findings could promote the development of PCDT and PTT synergistic therapy. Thus, this research provides a feasible direction to design a single, multifunctional material for cancer treatment.