Supramolecular Nanozyme-Based Cancer Catalytic Therapy

Manganese-doped carbon dots with catalase-like activity enable MRI-guided enhanced photodynamic therapy

The tumor microenvironment (TME) exhibits characteristics such as hypoxia, weak acidity, and enrichment of glutathione and hydrogen peroxide (H2O2), which greatly limits the effectiveness of tumor magnetic resonance imaging (MRI) and photodynamic therapy (PDT). Carbon dots (CDs) nanozymes are excellent candidate materials with both diagnostic and therapeutic potential. However, CDs nanozymes with both ultra-high relaxation rate and good therapeutic effect are still to be developed. Herein, novel carbon dots (MPC-CDs) were synthesized from polyethyleneimine (PEI), the photosensitizer hexahydroporphyrin (Ce6) and manganese. The Ce6 enabled the MPC-CDs to exhibit excellent PDT therapeutic ability, with a singlet oxygen yield as high as 1.52. The doping of the metal manganese gave the complexes CAT-like activity, and the singlet oxygen rate was further increased in the presence of H2O2, up to 1.97. In addition, manganese endowed the CDs with better MRI capabilities, and the r1 and r2 relaxation rates were significantly improved by 7.8-fold and 4.6-fold under acidic and H2O2 conditions. The in vitro and in vivo results showed that MPC-CDs could achieve TME-responsive MR imaging and synergistic anti-tumor effects, providing an effective strategy to further enhance the effectiveness of tumor diagnosis and treatment.

Enzyme-Mimetic, Cascade Catalysis-Based Triblock Polypeptide-Assembled Micelles for Enhanced Chemodynamic Therapy

Peptides and their conjugates are appealing as molecular scaffolds for constructing supramolecular biomaterials from the bottom up. Through strategic sequence design and interaction modulation, these peptides can self-assemble into diverse nanostructures that can, in turn, mimic the structural and catalytic functions of contemporary proteins. Here, inspired by the histidine brace active site identified in the metalloenzyme, we developed a triblock polypeptide with a hydrophobic polyleucine segment, a hydrophilic polylysine segment, and a terminal oligohistidine segment. This polypeptide demonstrates tunable and adaptive self-assembly morphologies. Moreover, copper ions can interact with the oligohistidine chelator and mediate the supramolecular assembly, generating metal-ligand centers for redox flow. The triblock polypeptide-based peptide micelles show Fenton-type activity with high substrate affinity when coassembled with copper ions. We have also engineered therapeutic micelles by coassembling two polypeptides, one integrated with copper ions and the other conjugated with glucose oxidase. This coassembled nanoplatform shows high in vitro and in vivo antitumor efficacy through a mechanism that combines triggered starvation and chemodynamic therapy. The versatility of this polypeptide sequence, which is compatible with various metal ions and functional ligands, paves the way for a broad spectrum of therapeutic and diagnostic applications.

Quantitative Intracellular Delivery of Anticancer Nanodrugs Via an Immunoassay Employing Pt-SiO2 Janus-Peroxidase Nanozyme

The accurate and efficient quantification of nanodrug dosage is crucial for early anticancer therapy. The enzyme-linked immunosorbent assay (ELISA) has emerged as a robust tool for detecting anticancer nanodrug dosage; however, the development of sensing elements to quantify anticancer nanodrugs still poses a challenge. To overcome this problem, we utilize polysuccinimide-loaded curcumin (CUR @PSIOAm) as a model to employ an ELISA based on peroxidase nanozyme Pt-SiO2 Janus nanoparticles (Pt-SiO2 JNPs) for the indirect quantitative analysis of intracellular anticancer nanodrug dosage. This novel approach employs an immunoassay to indirectly quantify the dosage of anticancer nanodrugs while preserving its structural integrity. The silica components of Pt-SiO2 JNPs adsorb intermediates, while the Pt NP components exhibit high catalytic activity. Pt-SiO2 JNPs are functionalized with anti-PSIOAm antibody (Pt-SiO2 JNPs-Ab) to serve as an immunosensor capable of specific recognition of CUR @PSIOAm. Additionally, we employed cytotoxicity assays and confocal imaging techniques to demonstrate the excellent biocompatibility of CUR @PSIOAm, as well as its specific uptake by cancer cells. According to the experimental results, the limit of detection (LOD) for the immunoassay of Pt-SiO2 JNPs as a marker for detecting CUR @PSIOAm is approximately 4.5-fold lower than that of horseradish peroxidase. Therefore, by optimizing the conditions, we established a direct competitive ELISA using Pt-SiO2 JNPs as colorimetric indicators for the quantitative detection of intracellular CUR @PSIOAm. The LOD for this ELISA was determined to be 0.01 ng/mL, while the loaded CUR amount calculated from the drug loading capacity was found to be 0.22 pg/mL. Furthermore, the recoveries obtained from this established ELISA ranged between 94.0 and 108%, demonstrating excellent accuracy. Consequently, the peroxidase mimic Pt-SiO2 JNPs-based ELISA exhibits significant potential for precise quantification of intracellular anticancer nanodrug dosages.

Mimicomes: Mimicking Multienzyme System by Artificial Design

Enzymes are widely distributed in organelles of cells, which are capable of carrying out specific catalytic reactions. In general, several enzymes collaborate to facilitate complex reactions and engage in vital biochemical processes within cells, which are also called cascade systems. The cascade systems are highly efficient, and their dysfunction is associated with a multitude of endogenous diseases. The advent of nanotechnology makes it possible to mimic these cascade systems in nature and realize partial functions of natural biological processes both in vitro and in vivo. To emphasize the significance of artificial cascade systems, mimicomes is first proposed, a new concept that refers to the artificial cascade catalytic systems. Typically, mimicomes are able to mimic specific natural biochemical catalytic processes or facilitate the overall catalytic efficiency of cascade systems. Subsequently, the evolution and development of different types of mimicomes in recent decades are elucidated exhaustedly, from the natural enzyme-based mimicomes (immobilized enzyme and vesicle mimicomes) to the nanozyme-based mimicomes and enzyme-nanozyme hybrid mimicomes. In conclusion, the remaining challenges in the design of multifunctional mimicomes and their potential applications are summarized, offering insights into their future prospects.

Reaction Mechanisms and Kinetics of Nanozymes: Insights from Theory and Computation

"Nanozymes" usually refers to inorganic nanomaterials with enzyme-like catalytic activities. The research into nanozymes is one of the hot topics on the horizon of interdisciplinary science involving materials, chemistry, and biology. Although great progress has been made in the design, synthesis, characterization, and application of nanozymes, the study of the underlying microscopic mechanisms and kinetics is still not straightforward. Density functional theory (DFT) calculations compute the potential energy surfaces along the reaction coordinates for chemical reactions, which can give atomistic-level insights into the micro-mechanisms and kinetics for nanozymes. Therefore, DFT calculations have been playing an increasingly important role in exploring the mechanisms and kinetics for nanozymes in the past years. The calculations either predict the microscopic details for the catalytic processes to complement the experiments or further develop theoretical models to depict the physicochemical rules. In this review, the corresponding research progress is summarized. Particularly, the review focuses on the computational studies that closely interplay with the experiments. The relevant experimental results without DFT calculations will be also briefly discussed to offer a historic overview of how the computations promote the understanding of the microscopic mechanisms and kinetics of nanozymes.

Fibrous Zr-MOF Nanozyme Aerogels with Macro-Nanoporous Structure for Enhanced Catalytic Hydrolysis of Organophosphate Toxins

Metal-organic frameworks (MOFs) with Lewis acid catalytic sites, such as zirconium-based MOFs (Zr-MOFs), comprise a growing class of phosphatase-like nanozymes that can degrade toxic organophosphate pesticides and nerve agents. Rationally engineering and shaping MOFs from as-synthesized powders into hierarchically porous monoliths is essential for their use in emerging applications, such as filters for air and water purification and personal protection gear. However, several challenges still limit the production of practical MOF composites, including the need for sophisticated reaction conditions, low MOF catalyst loadings in the resulting composites, and poor accessibility to MOF-based active sites. To overcome these limitations, a rapid synthesis method is developed to introduce Zr-MOF nanozyme coating into cellulose nanofibers, resulting in the formation of processable monolithic aerogel composites with high MOF loadings. These composites contain Zr-MOF nanozymes embedded in the structure, and hierarchical macro-micro porosity enables excellent accessibility to catalytic active sites. This multifaceted rational design strategy, including the selection of a MOF with many catalytic sites, fine-tuning the coating morphology, and the fabrication of a hierarchically structured monolithic aerogel, renders synergistic effects toward the efficient continuous hydrolytic detoxification of organophosphorus-based nerve agent simulants and pesticides from contaminated water.

Co-based Nanozymatic Profiling: Advances Spanning Chemistry, Biomedical, and Environmental Sciences

Nanozymes, next-generation enzyme-mimicking nanomaterials, have entered an era of rational design; among them, Co-based nanozymes have emerged as captivating players over times. Co-based nanozymes have been developed and have garnered significant attention over the past five years. Their extraordinary properties, including regulatable enzymatic activity, stability, and multifunctionality stemming from magnetic properties, photothermal conversion effects, cavitation effects, and relaxation efficiency, have made Co-based nanozymes a rising star. This review presents the first comprehensive profiling of the Co-based nanozymes in the chemistry, biology, and environmental sciences. The review begins by scrutinizing the various synthetic methods employed for Co-based nanozyme fabrication, such as template and sol-gel methods, highlighting their distinctive merits from a chemical standpoint. Furthermore, a detailed exploration of their wide-ranging applications in biosensing and biomedical therapeutics, as well as their contributions to environmental monitoring and remediation is provided. Notably, drawing inspiration from state-of-the-art techniques such as omics, a comprehensive analysis of Co-based nanozymes is undertaken, employing analogous statistical methodologies to provide valuable guidance. To conclude, a comprehensive outlook on the challenges and prospects for Co-based nanozymes is presented, spanning from microscopic physicochemical mechanisms to macroscopic clinical translational applications.

Manganese Amplifies Photoinduced ROS in Toluidine Blue Carbon Dots to Boost MRI Guided Chemo/Photodynamic Therapy

The contrast agents and tumor treatments currently used in clinical practice are far from satisfactory, due to the specificity of the tumor microenvironment (TME). Identification of diagnostic and therapeutic reagents with strong contrast and therapeutic effect remains a great challenge. Herein, a novel carbon dot nanozyme (Mn-CD) is synthesized for the first time using toluidine blue (TB) and manganese as raw materials. As expected, the enhanced magnetic resonance (MR) imaging capability of Mn-CDs is realized in response to the TME (acidity and glutathione), and r1 and r2 relaxation rates are enhanced by 224% and 249%, respectively. In addition, the photostability of Mn-CDs is also improved, and show an efficient singlet oxygen (1 O2 ) yield of 1.68. Moreover, Mn-CDs can also perform high-efficiency peroxidase (POD)-like activity and catalyze hydrogen peroxide to hydroxyl radicals, which is greatly improved under the light condition. The results both in vitro and in vivo demonstrate that the Mn-CDs are able to achieve real-time MR imaging of TME responsiveness through aggregation of the enhanced permeability and retention effect at tumor sites and facilitate light-enhanced chemodynamic and photodynamic combination therapies. This work opens a new perspective in terms of the role of carbon nanomaterials in integrated diagnosis and treatment of diseases.

Coordination-Driven One-Step Rapid Self-Assembly Synthesis of Dual-Functional Ag@Pt Nanozyme

Realizing high-precise and adjustable regulation of engineering nanozyme is important in nanotechnology. Here, Ag@Pt nanozymes with excellent peroxidase-like and antibacterial effects are designed and synthesized by nucleic acid and metal ions coordination-driven one-step rapid self-assembly. The adjustable NA-Ag@Pt nanozyme is synthesized within 4 min using single-stranded nucleic acid as templates, and peroxidase-like enhancing FNA-Ag@Pt nanozyme is received by regulating functional nucleic acids (FNA) based on NA-Ag@Pt nanozyme. Both Ag@Pt nanozymes that are developed not only has simple and general synthesis approaches, but also can produce artificial precise adjustment and possess dual-functional. Moreover, when lead ion-specific aptamers as FNA are introduced to NA-Ag@Pt nanozyme, the Pb2+ aptasensor is successfully constructed by increasing electron conversion efficiency and improving the specificity of nanozyme. In addition, both nanozyme has good antibacterial properties, with ~100% and ~85% antibacterial efficiency against Escherichia coli and Staphylococcus aureus, respectively. This work provides a synthesis method of novelty dual-functional Ag@Pt nanozymes and successful application in metal ions detection and antibacterial agents.

Colorimetric platform based on synergistic effect between bacteriophage and AuPt nanozyme for determination of Yersinia pseudotuberculosis

The development of a novel colorimetric method is reported, using vB_YepM_ZN18 phages along with AuPt nanozyme for the sensitive detection of Y. pseudotuberculosis. The phage used in this work has been extracted from hospital sewer water and is highly specific toward Y. pseudotuberculosis. The synthesized AuPt NPs possess peroxidase-like activity, which is suitable in the development of nanozyme based detection system. Furthermore, phages@MB and AuPt@phages are added into the bacterial samples for co-incubation, forming an intercalated complex. The magnetic separation and absorbance analysis of enzymatic reaction are carried out for the detection of targeted bacteria. The proposed method has a limit of detection of 14 CFU/mL, a wide linear range from 2.50 × 10¹ ~ 2.50 × 10⁷ CFU/mL and the assay completion time is 40 min. Benefitting from the outperformance of this sensor, we have successfully employed the developed sensing platform for the detection of Y. pseudotuberculosis in food industry and hospital specimens.

Aza-BODIPY-based Fluorescent and Colorimetric Sensors and Probes

Aza-boron-dipyrromethenes (Aza-BODIPYs) represent an important class of chromophores absorbing and emitting in the near-infrared (NIR) region. They have unique optical and electronic features and higher physiological and photo stability than other NIR dyes. Especially after the development of facile synthetic routes, Aza-BODIPYs have become indispensable fluors that can find various applications ranging from chemosensors, bioimaging, phototherapy, solar energy materials, photocatalysis, photon upconversion, lasers, and optoelectronics. Herein, we review Aza-BODIPY based fluorescent and colorimetric chemosensors. We show the potential and untapped toolbox of Aza-BODIPY based fluorescent and colorimetric chemosensors. Hence, we divide the fluorescent and colorimetric chemosensors and probes into five sections according to the target analytes. The first section begins with the chemosensors developed for pH. Next, we discuss Aza-BODIPY based ion sensors, including metal ions and anions. Finally, we present the chemosensors and probes concerning reactive oxygen (ROS) and nitrogen species (RNS) along with biologically relevant species in the last two sections. We believe that Aza-BODIPYs are still in their infancy, and they have a promising future for translation from the bench to real biomedical and materials science applications. After two decades of intensive research, it seems that there are many more to come in this already fertile field. Overall, we hope that future work will further expand the applications of Aza-BODIPY in many areas.

Lentinan stabilized bimetallic PdPt3 dendritic nanoparticles with enhanced oxidase-like property for L-cysteine detection

The development of nanozymes with enhanced catalytic activity has been drawing great interest. Lentinan with special structure may be used to prepare bimetallic nanomaterials to enhance their catalytic activity. Herein, lentinan stabilized PdPt₃ dendritic nanoparticles (PdPt₃-LNT NDs) were prepared through reduction of Na₂PdCl₄ and K₂PtCl₄ with a molar ratio of 1:3 using lentinan as a biological template. PdPt₃-LNT NDs had dendritic shape with size of 10.76 ± 1.82 nm. PdPt₃-LNT NDs had the hydrodynamic size about 25.7 nm and the zeta potential between -1.4 mV and - 4.9 mV at different pH. Furthermore, PdPt₃-LNT NDs catalyzed 3,3',5,5'-tetramethylbenzidine (TMB) to produce oxidized TMB, suggesting their oxidase-like property. The catalytic activity of PdPt₃-LNT NDs was the highest when pH was 4 and the temperature was 40 °C. The catalytic mechanism was the generation of ·O₂^- and ¹O₂ from O₂ catalyzed by PdPt₃-LNT NDs. More importantly, L-cysteine detection method was set up based on the oxidase-like property of PdPt₃-LNT NDs. This method had wide linear range for 0-200 μM and low detection limit for 3.099 μM. Taken together, PdPt₃-LNT NDs have good potential applications in bio-related detection in the future.

Exogenously Triggered Nanozyme for Real-Time Magnetic Resonance Imaging-Guided Synergistic Cascade Tumor Therapy

The uncontrolled treatment process and high concentration of intracellular glutathione compromise the therapeutic efficacies of chemodynamic therapy (CDT). Here, iron oxide nanocrystals embedded in N-doped carbon nanosheets (IONCNs) are designed as a near-infrared light-triggered nanozyme for synergistic cascade tumor therapy. The IONCNs can absorb and convert 980 nm light to local heat, which induces the dissolution of iron oxide for generating Fe²⁺/Fe³⁺ in a weak acid environment, apart from thermal ablation of cancer cells. The formed Fe²⁺ takes on the active site for the Fenton reaction. The formed Fe³⁺ acts as glutathione peroxidase to magnify oxidative stress, improving the antitumor performance. The IONCNs can be used to visually track the treatment process via magnetic resonance imaging. Such IONCNs demonstrate great potential as an exogenously triggered nanozyme via an integrated cascade reaction for imaging-guided synergistic cancer therapy.

AIEgen-Based Bionic Nanozymes for the Interventional Photodynamic Therapy-Based Treatment of Orthotopic Colon Cancer

Relative to traditional photosensitizer (PS) agents, those that exhibit aggregation-induced emission (AIE) properties offer key advantages in the context of photodynamic therapy (PDT). At present, PDT efficacy is markedly constrained by the hypoxic microenvironment within tumors and the limited depth to which lasers can penetrate in a therapeutic context. Herein, we developed platelet-mimicking MnO2 nanozyme/AIEgen composites (PMD) for use in the interventional PDT treatment of hypoxic tumors. The resultant biomimetic nanoparticles (NPs) exhibited excellent stability and were able to efficiently target tumors. Moreover, they were able to generate O2 within the tumor microenvironment owing to their catalase-like activity. Notably, through an interventional approach in which an optical fiber was introduced into the abdominal cavity of mice harboring orthotopic colon tumors, good PDT efficacy was achieved. We thus propose that a novel strategy consisting of a combination of an AIEgen-based bionic nanozyme and a biomimetic cell membrane coating represents an ideal therapeutic platform for targeted antitumor PDT. This study is the first to have combined interventional therapy and AIEgen-based PDT, thereby overcoming the limited light penetration that typically constrains the therapeutic efficacy of this technique, highlighting a promising new AIEgen-based PDT treatment strategy.

Nanozymes: Versatile Platforms for Cancer Diagnosis and Therapy

Natural enzymes usually suffer from high production cost, ease of denaturation and inactivation, and low yield, making them difficult to be broadly applicable. As an emerging type of artificial enzyme, nanozymes that combine the characteristics of nanomaterials and enzymes are promising alternatives. On the one hand, nanozymes have high enzyme-like catalytic activities to regulate biochemical reactions. On the other hand, nanozymes also inherit the properties of nanomaterials, which can ameliorate the shortcomings of natural enzymes and serve as versatile platforms for diverse applications. In this review, various nanozymes that mimic the catalytic activity of different enzymes are introduced. The achievements of nanozymes in different cancer diagnosis and treatment technologies are summarized by highlighting the advantages of nanozymes in these applications. Finally, future research directions in this rapidly developing field are outlooked.

Ultrasmall Manganese Ferrites for In Vivo Catalase Mimicking Activity and Multimodal Bioimaging

Manganese ferrite nanoparticles display interesting features in bioimaging and catalytic therapies. They have been recently used in theranostics as contrast agents in magnetic resonance imaging (MRI), and as catalase-mimicking nanozymes for hypoxia alleviation. These promising applications encourage the development of novel synthetic procedures to enhance the bioimaging and catalytic properties of these nanomaterials simultaneously. Herein, a cost-efficient synthetic microwave method is developed to manufacture ultrasmall manganese ferrite nanoparticles as advanced multimodal contrast agents in MRI and positron emission tomography (PET), and improved nanozymes. Such a synthetic method allows doping ferrites with Mn in a wide stoichiometric range (Mn_x Fe_3-x O₄ , 0.1 ≤ x ≤ 2.4), affording a library of nanoparticles with different magnetic relaxivities and catalytic properties. These tuned magnetic properties give rise to either positive or dual-mode MRI contrast agents. On the other hand, higher levels of Mn doping enhance the catalytic efficiency of the resulting nanozymes. Finally, through their intracellular catalase-mimicking activity, these ultrasmall manganese ferrite nanoparticles induce an unprecedented tumor growth inhibition in a breast cancer murine model. All of these results show the robust characteristics of these nanoparticles for nanobiotechnological applications.

Selective Fluorescence Imaging of Cancer Cells Based on ROS-Triggered Intracellular Cross-Linking of Artificial Enzyme

Inside living cells, regulation of catalytic activity of artificial enzymes remains challenging due to issues such as biocompatibility, efficiency, and stability of the catalyst, by which the practical applications of artificial enzymes have been severely hindered. Here, an artificial enzyme, PTT-SGH, with responsiveness to reactive oxygen species (ROS), was obtained by introducing a catalytic histidine residue to pentaerythritol tetra(3-mercaptopropionate) (PTT). The artificial enzyme formed large aggregates in cells via the intracellular ROS-mediated oxidation of thiol groups. The process was significantly facilitated in tumor cells because of the higher ROS concentration in the tumor microenvironment. The catalytic activity of this artificial enzyme was intensively enhanced through deprotonation of cross-linked PTT-SGH, which showed typical esterase activities. Selective fluorescence imaging of tumor cells was achieved using the artificial enzyme to trigger the cleavage of the ester bond of the caged fluorophore inside living cells.

Albumin-mediated “Unlocking” of supramolecular prodrug-like nanozymes toward selective imaging-guided phototherapy

An adaptive nanozyme without producing off-target toxicity has been successfully applied in phototherapy.

N-doped MoS2-nanoflowers as peroxidase-like nanozymes for total antioxidant capacity assay

Total Antioxidant Capacity (TAC) Assay plays an important role in evaluating the quality of antioxidant food and monitoring the oxidative stress level of human body. It is mainly achieved by measuring the contents of antioxidants such as AA, L-Cys and GSH, while TAC can be detected by using peroxidase-like activity of artificial nanoenzyme materials. In this work, the N-Doped, defect-rich N-MoS₂NFs nano-materials were used to build the nano enzyme, which has strong stability and high peroxidase-like activity. H₂O₂ was detected because it can be catalyzed to generate the intermediate ·OH and make TMB appears blue. However, when H₂O₂, AA, L-Cys and GSH coexist in solution, due to the oxidation resistance of AA, L-Cys and GSH, they can competitively react with ·OH in solution or reduce TMB in oxidation state (oxTMB), which reduces the characteristic absorption of oxTMB, indirectly achieves the purpose of detecting AA, L-Cys and GSH, and finally realizes the determination of TAC, even in actual serum and saliva samples. At the same time, the N-MoS₂ NFs/NH₂-MIL-53(Al)+OPD system is further constructed. Based on the fluorescence resonance energy transfer (FRET) between NH₂-MIL-53(Al) and oxidized OPD (oxOPD), the purpose of detecting TAC by fluorescence method was realized.

A metastasis suppressor Pt-dendrimer nanozyme for the alleviation of glioblastoma

Nanozymes are nanostructure-based materials which mimic the enzymatic characteristics of natural enzymes. Biological applications of nanozymes have been highlighted in basic research, industry, and translational medicine as a new cutting-edge tool. In this work, and for the first time, we disclose a tumor alleviation property of a nanozyme that is made up of amine-terminated sixth-generation polyamidoamine dendrimers with encapsulated tiny platinum nanoparticles. We systematically conducted the synthesis and characterization of the dendrimer-encapsulated Pt nanoparticles (denoted Pt-dendrimer) and confirmed their enzymatic function (hydrogen peroxide (H2O2) decomposition) within various cell lines (normal, cancerous), including glioblastoma (GBM) cells. By understanding the effects of the Pt-dendrimer at the gene level, especially related to cancer cell metastasis, we have thoroughly demonstrated its ability for tumor alleviation and suppressing GBM migration, invasion, and adhesion. The present findings show great promise for the application of the nanozyme for use in GBM-related basic research as well as at clinical sites.

An Ultra-Stable, Oxygen-Supply Nanoprobe Emitting in Near-Infrared-II Window to Guide and Enhance Radiotherapy by Promoting Anti-Tumor Immunity

Currently, radiotherapy (RT) is the main method for cancer treatment. However, the hypoxic environment of solid tumors is likely to cause resistance or failure of RT. Moreover, high-dose radiation may cause side effects to surrounding normal tissues. In this study, a new type of nanozyme is developed by doping Mn (II) ions into Ag₂ Se quantum dots (QDs) emitting in the second near-infrared window (NIR-II, 1000-1700 nm). Through the catalysis of Mn (II) ions, the nanozymes can trigger the rapid decomposition of H₂ O₂ and produce O₂ . Conjugated with tumor-targeting arginine-glycine-aspartate (RGD) tripeptides and polyethylene glycol (PEG) molecules, the nanozymes are then constructed into in vivo nanoprobes for NIR-II imaging-guided RT of tumors. Owing to the radiosensitive activity of the element Ag, the nanoprobes can promote radiation energy deposition. The specific tumor-targeting and NIR-II emitting abilities of the nanoprobes facilitate the precise tumor localization, which enables precise RT with low side effects. Moreover, their ultra-stability in the living body ensures that the nanoprobes continuously produce oxygen and relieve the hypoxia of tumors to enhance RT efficacy. Guided by real-time and high-clarity imaging, the nanoprobe-mediated RT promotes anti-tumor immunity, which significantly inhibits the growth of tumors or even cures them completely.