Au@Pt nanoparticles as catalase mimics to attenuate tumor hypoxia and enhance immune cell-mediated cytotoxicity

Hypoxic tumor microenvironment (TME) is closely linked to tumor progression, heterogeneity and immune suppression. Therefore, the development of effective methods to overcome hypoxia and substantially enhance the immunotherapy efficacy remains a desirable goal. Herein, we engineered a biocompatible Au core/Pt shell nanoparticles (Au@PtNPs) to reoxygenate the TME by reacting with endogenous H2O2. Treatment with Au@PtNPs appeared to improve oxygen in intracellular environments and decrease hypoxia-inducible factor-1 alpha expression. Furthermore, the integration of high catalytic efficiency of Au@PtNPs with cytokine-induced killer (CIK) cell immunotherapy, could lead to significantly improve the effect of CIK cell-mediated cytotoxicity. These results suggest great potential of Au@PtNPs for regulation of the hypoxic TME and enhance immune cell mediated anti-tumor immunity.