Anticancer Tetranuclear Cu(I) Complex Catalyzes a Click Reaction to Synthesize a Chemotherapeutic Agent in situ to Achieve Targeted Dual‐Agent Combination Therapy for Cancer

To develop next‐generation metal‐based drugs and dual‐drug combination therapy for cancer, we proposed to develop a copper (Cu) complex that exerts anticancer function by integrating chemotherapy, immunotherapy and catalyzes a click reaction for the in situ synthesis of a chemotherapeutic agent, thereby achieving targeted dual‐agent combination therapy. We designed and synthesized a tetranuclear Cu(I) complex (Cu4) with remarkable cytotoxicity and notable catalytic ability for the in situ synthesis of a chemotherapeutic agent via Cu(I)‐catalyzed azide‐alkyne 1,3‐cycloaddition (CuAAC). We also constructed an apoferritin (AFt)‐Cu4 nanoparticles (NPs) delivery system. AFt‐Cu4 NPs not only showed an enhanced performance of tumor growth inhibition, but also improved the targeting ability and reduced the systemic toxicity of Cu4 in vivo. Importantly, the anticancer effect was enhanced by combining the AFt‐Cu4 NPs with the resveratrol analogue obtained from the CuAAC reaction in situ. Finally, we revealed the anticancer mechanism of the Cu4/AFt‐Cu4 NPs, which involves both cuproptosis and cuproptosis‐induced systemic immune response.