Nanozymes are nanomaterials with enzyme-like properties that have attracted significant interest owing to their high stability, easy preparation, and tunable catalytic properties, especially in the field of cancer therapy. However, the unfavorable catalytic effects of nanozymes in the acidic tumor microenvironment have limited their applications. Herein, we developed a biomimetic erythrocyte membrane-camouflaged ultrasmall black phosphorus quantum dots (BPQDs) nanozymes that simultaneously exhibited an exceptional near-infrared (NIR) photothermal property and dramatically photothermal-enhanced glucose oxidase (GOx)-like activity in the acidic tumor microenvironment. We demonstrated the engineered BPQDs gave a photothermal conversion efficiency of 28.9% that could rapidly heat the tumor up to 50 ℃ while effectively localized into tumors via homing peptide iRGD leading after intravenously injection. Meanwhile, the significantly enhanced GOx-like activity of BPQDs under NIR irradiation was capable of catalytical generating massive toxic reactive oxygen species via using cellular glucose. By combining the intrinsic photothermal property and the unique photothermal-enhanced GOx-like catalytic activity, the developed BPQDs were demonstrated to be an effective therapeutic strategy for inhibiting tumor growth in vivo. We believe that this work will provide a novel perspective for the development of nanozymes in tumor catalytic therapy.

Atherosclerotic plaque rupture results in thrombus formation and vessel occlusion, and is the leading cause of death worldwide. There is a pressing need to identify plaque vulnerability for the treatment of carotid and coronary artery diseases. Nanomaterials with enzyme-like properties have attracted significant interest by providing biological, diagnostic and prognostic information about the diseases. Here we showed that bioengineered magnetoferritin nanoparticles (M-HFn NPs) functionally mimic peroxidase enzyme and can intrinsically recognize plaque-infiltrated active macrophages, which drive atherosclerotic plaque progression and rupture and are significantly associated with the plaque vulnerability. The M-HFn nanozymes catalyze the oxidation of colorimetric substrates to give a color reaction that visualizes the recognized active macrophages for one-step pathological identification of plaque vulnerability. We examined 50 carotid endarterectomy specimens from patients with symptomatic carotid disease and demonstrated that the M-HFn nanozymes could distinguish active macrophage infiltration in ruptured and high-risk plaque tissues, and M-HFn staining displayed a significant correlation with plaque vulnerability (r = 0.89, P < 0.0001).