Nanozymes-Engineered Metal-Organic Frameworks for Catalytic Cascades-Enhanced Synergistic Cancer Therapy.

The efficiency of chemical intercommunication between enzymes in natural networks can be significantly enhanced by the organized catalytic cascades. Nevertheless, the exploration of two-or-more-enzymes-engineered nanoreactors for catalytic cascades remains a great challenge in cancer therapy because of the inherent drawbacks of natural enzymes. Here, encouraged by the catalytic activity of the individual nanozyme for benefiting the treatment of solid tumors, we propose an organized in situ catalytic cascades-enhanced synergistic therapeutic strategy driven by dual-nanozymes-engineered porphyrin metal-organic frameworks (PCN). Precisely, catalase-mimicking platinum nanoparticles (Pt NPs) were sandwiched by PCN, followed by embedding glucose oxidase-mimicking ultrasmall gold nanoparticles (Au NPs) within the outer shell, and further coordination with folic acid (P@Pt@P-Au-FA). The Pt NPs effectively enabled tumor hypoxia relief by catalyzing the intratumoral H2O2 to O2 for (1) enhancing the O2-dependent photodynamic therapy and (2) subsequently accelerating the depletion of β-d-glucose by Au NPs for synergistic starving-like therapy with the self-produced H2O2 as the substrate for Pt NPs. Consequently, a remarkably strengthened antitumor efficiency with prevention of tumor recurrence and metastasis was achieved. This work highlights a rationally designed tumor microenvironment-specific nanoreactor for opening improved research in nanozymes and provides a means to design a catalytic cascade model for practical applications.