pH/glutathione-responsive release of SO2 induced superoxide radical accumulation for gas therapy of cancer.

A pH/GSH-responsive SO2 generation nanoplatform (BODS NPs) is established to achieve lysosomal escape and GSH depletion in tumor cells. O2˙- as the main ROS during SO2-mediated gas therapy can be accumulated through Cu/Zn-SOD enzymatic activity suppression and mitochondrial biogenesis, further exacerbating the oxidative stress and resulting in cell apoptosis.