Construction of Cu/ZIF-67/Prussian Blue Nanostructures with Photothermal-Enhanced Multizyme Activity for Cancer Therapy

Nanozymes that mimic the catalytic reaction of naturalenzymesshow great prospects for tumor catalytic therapy because they possessthe properties of nanomaterials and natural enzymes. However, thetherapeutic effect of nanozymes is restricted by the low catalyticefficiency and specific oxidation-reduction systems in thetumor microenvironment (TME), such as overexpressed glutathione (GSH)level. In order to improve the catalytic efficiency, a multifunctionalnanozyme, Cu/zeolitic imidazolate framework-67 (ZIF-67)/Prussian blue(PB), was designed through the modification of Prussian blue (PB)on the surface of the copper-doped zeolitic imidazolate framework,which can be used for imaging-guided synergistic therapy with photothermal-enhancedmultienzyme-like catalytic therapy and chemotherapy. The doping ofCu(2+) provided better glutathione oxidase-like (GPx-like)activity and peroxidase-like (POD-like) activity to deplete GSH andincrease the generation of (OH)-O-center dot in TME. The modificationof PB provided better catalase-like activity (CAT-like) to promotethe production of O-2 and enhance the multienzyme-like catalytictherapy. In vivo experiments showed a satisfactoryanticancer effect. This work thus provided a strategy for designinga type of multifunctional nanozyme for imaging-guided combinationtherapy.