SiO2@Cu7S4 nanotubes for photo/chemodynamic and photo-thermal 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, provided a highly effective Fenton reagent is developed. In this research, SiO2@Cu7S4 nanotubes (NTs) were synthesized as a PCDT agent. This double-valence metal-sulfide composite material can react with H2O2 at the tumor site. SiO2@Cu7S4 NTs can produce more ROS than the traditional PDT agents, and besides, they can also be used as a photothermal therapy (PTT) agent. SiO2@Cu7S4 NTs will trigger the PTT effect under 808 nm irradiation and generate a large amount of heat to eradicate cancer cells. This heat will also promote the PCDT effect by increasing the reaction rate. Thus, the 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 NTs. Furthermore, the findings could promote the development of PCDT and PTT synergistic therapy. Thus, this research provides a feasible method to design a single, multifunctional material for cancer treatment.