Multiple in-situ reactions induced by biodegradable iodides: A synergistically chemodynamic-photothermal therapy platform

Integrating multifunctional nanostructures and effectively modulating the tumor microenvironment (TME) is a need for precision nanotherapy. In this work, cuprous iodide-palladium iodides (CPIs) nanoenzymes were designed for infrared thermal (IR) and computed tomography (CT) imaging-guided synergistic chemodynamicphotothermal therapy (CDT and PTT) of tumor. CPIs act as peroxidase (POD)-like enzymes to catalyze the generation of hydroxyl radicals (center dot OH) from endogenous H2O2, and also reduce the excess glutathione (GSH) in the TME to relieve tumor antioxidant ability, which enhance the effect of CDT. More importantly, due to the promoted non-radiative recombination of carries, the CPIs shift the light absorption range to the near-infrared region and confer higher photothermal conversion efficiency (47.72%), which improves the photothermal therapeutic effect and accelerate the generation rate of center dot OH. Furthermore, the CT images exhibited by CPIs can help guide synergistic CDT/PTT treatment due to the high X-ray attenuation coefficient of the I-element. Finally, based on the dual oxidation of Cu(I) and I(I), the CPIs can be degraded to avoid long-term toxicity after inhibiting tumor growth. All in all, this nanotherapeutic platform constructed by iodides provide a possibility to simultaneously meet the biodegradability and imaging-guided synergistic chemodynamic-photothermal therapy.