“Block and attack” strategy for tumor therapy through ZnO2/siRNA/NIR‐mediating Zn2+‐overload and amplified oxidative stress

Intracellular zinc ion (Zn2+) accumulation disrupts the Zn2+ homeostasis, providing an ion‐overloading anticancer strategy with great potential. The self‐adaptation of tumor cells to ion concentration, however, puts forward higher requirements for the design of ion‐overloading strategy. Herein, “block and attack” antitumor strategy was applied through a composite nanomaterials (UHSsPZH NPs). The strategy demonstrated powerful ion interference ability through both “blocking” the efflux of excess Zn2+ via gene silencing and “attacking” tumor cells via target delivery of ZnO2. After cellular internalization, ZnO2 was degraded to Zn2+ and hydrogen peroxide (H2O2), and the gene expression of zinc transporter 1 (ZnT1) was silenced by targeting of released siRNA, which together caused intracellular Zn2+‐overload. Disorder of Zn2+ further interfered with intracellular Ca2+ homeostasis, inhibited the electron transport chain and promoted the production of endogenous reactive oxygen species (ROS), which assisted the “attack” to tumor cells together with the exogenous ROS generated by UHSsPZH NPs under 980 nm laser irradiation. In summary, this work supplies a “block and attack” strategy for the application of ion homeostasis interference in tumor therapy. The UHSsPZH NPs can not only efficiently “attack” tumor cells through targeted delivery of ZnO2 and the combined action of PDT, but also “block” the efflux of excess Zn2+ by tumor cells through gene silencing, thus demonstrating a powerful ion interference function and anti‐tumor effect.