Near‐Infrared Light‐Triggered Chlorine Radical (^.Cl) Stress for Cancer Therapy

Abstract

Free radicals with reactive chemical properties can fight tumors without causing drug resistance. Reactive oxygen species (ROS) has been widely used for cancer treatment, but regrettably, the common O₂ and H₂ O₂ deficiency in tumors sets a severe barrier for sufficient ROS production, leading to unsatisfactory anticancer outcomes. Here, we construct a chlorine radical (^. Cl) nano-generator with SiO₂ -coated upconversion nanoparticles (UCNPs) on the inside and Ag⁰ /AgCl hetero-dots on the outside. Upon near-infrared (NIR) light irradiation, the short-wavelength emission UCNP catalyzes ^. Cl generation from Ag⁰ /AgCl with no dependence on O₂ /H₂ O₂ . ^. Cl with strong oxidizing capacity and nucleophilicity can attack biomolecules in cancer cells more effectively than ROS. This ^. Cl stress treatment will no doubt broaden the family of oxidative stress-induced antitumor strategies by using non-oxygen free radicals, which is significant in the development of new anticancer agents.