Hydrogel co-loading SO2 prodrug and FeGA nanoparticles for enhancing chemodynamic therapy by photothermal-triggered SO2 gas therapy

Chemodynamic therapy (CDT) is an effective anti-tumor method, while CDT alone cannot achieve a good therapeutic effect. Moreover, the overexpression of glutathione (GSH) in tumor cells dramatically limits the efficiency of CDT. Here, we proposed a hydrogel co-loading SO 2 prodrug and FeGA nanoparticles (NPs) for enhancing CDT by photothermal-triggered SO 2 gas therapy (FBH) system by mixing benzothiazolyl sulfonates (BTS) and FeGA NPs in a certain ratio and encapsulating them in a heat-sensitive hydrogel. FeGA NPs could accelerate the release of Fe 2+ under acidic conditions and light, and combine with excess H 2 O 2 in the tumor for chemokinetic treatment. BTS, as a water-soluble prodrug of SO 2 , can accurately control the release of SO 2 gas by virtue of the excellent photothermal conversion ability of FeGA NPs and the acidic pH value of tumor site. SO 2 can not only induce cell apoptosis, but also consume excess GSH in cancer cells and increase the content of reactive oxygen species, which seriously destroyed the redox balance in cancer cells and further promotes the therapeutic effect of Fenton reaction. The intelligent FBH system provided a new approach for the synergistic treatment of CDT and SO 2 gas, which demonstrated good anticancer effects both in vivo and in vitro .