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Although Prussian blue nanozymes (PBNZ) are widely applied in various fields, their catalytic mechanisms remain elusive. Here, we investigate the long-term catalytic performance of PBNZ as peroxidase (POD) and catalase (CAT) mimetics to elucidate their lifespan and underlying mechanisms. Unlike our previously reported Fe 3 O 4 nanozymes, which exhibit depletable POD-like activity, the POD and CAT-like activities of PBNZ not only persist but slightly enhance over prolonged catalysis. We demonstrate that the irreversible oxidation of PBNZ significantly promotes catalysis, leading to self-increasing catalytic activities. The catalytic process of the pre-oxidized PBNZ can be initiated through either the conduction band pathway or the valence band pathway. In summary, we reveal that PBNZ follows a dual-path electron transfer mechanism during the POD and CAT-like catalysis, offering the advantage of a long service life. Sustained catalytic performance wound benefit the applications of nanozymes, but the catalytic activity of some nanozymes depletes with time. Here the authors report Prussian blue nanozymes that exhibit self-increasing catalytic activity and elucidate the underlying catalytic mechanisms.

Prussian blue nanoparticles (PBNPs) have emerged as versatile nanozymes with reactive oxygen species (ROS)-scavenging capabilities, predominantly applied in antioxidant therapies. In this work, we present a combined theoretical and experimental study demonstrating that modulating Fe coordination environments can fundamentally reconfigure PBNPs’ catalytic properties, enabling ROS generation and pro-oxidative functionality. Ab initio molecular dynamics revealed different H 2 O 2 lysis mechanisms at Fe sites with varying coordination numbers: Low-coordinated center (FeN 4 ) induced hydrogen atom transfer to form Fe=O species, while high-coordinated FeN 5 generated ·OH radicals via H + -assisted homolysis under acidic conditions. Guided by calculations, Cs-doped PBNPs (Cs-PBs) with elevated coordination numbers were synthesized via alkali cation stoichiometric control, leveraging high distribution coefficient and low hydration energy of Cs + . Experimental results confirmed radical generation in Cs-PBs aligned with theoretical predictions. The size-optimized Cs-PBs demonstrated ultrahigh peroxidase-like activity (1182.26 U·mg -1 ) and outperformed ROS generating properties in both pollutant degradation and chemodynamic therapy. This work redefines PBNPs’ catalytic potential beyond conventional antioxidant roles, and lays the foundation for innovative environmental and therapeutic solutions. While Prussian blue (PB) nanozymes are typically employed as antioxidants, their reactive oxygen species-generating capability remains unexplored. Here, the authors predict by molecular dynamics and identify explicit hydroxyl radical generation in highly crystalline cesium-doped PBs.

In recent years, hydrogel-based cancer drug delivery systems have developed rapidly due to the versatility of hydrogels [...].In recent years, hydrogel-based cancer drug delivery systems have developed rapidly due to the versatility of hydrogels [...].

Highlights This review uniquely provides an in-depth focus on the stability issues of single-atom nanozymes (SAzymes), covering multiple aspects such as metal atom clustering and active site loss, ligand bond breakage at high temperature, insufficient environment tolerance, biosecurity risks, and limited catalytic long-term stability. This review integrates and systematically discusses a wide range of potential strategies to overcome stability issues, including synthesis process optimization (space-limited strategy, coordination site design, bimetallic synergistic strategy, defect engineering strategy, atom stripping-capture), surface modification, and dynamic responsive design. To transform SAzymes from “star materials” of the laboratory into precise clinical tools for medicine, the authors propose the four-dimensional roadmap: structure-predictable, activity-tunable, biocompatible, and scalable. Single-atom nanozymes (SAzymes) exhibit exceptional catalytic efficiency due to their maximized atom utilization and precisely modulated metal-carrier interactions, which have attracted significant attention in the biomedical field. However, stability issues may impede the clinical translation of SAzymes. This review provides a comprehensive overview of the applications of SAzymes in various biomedical fields, including disease diagnosis (e.g., biosensors and diagnostic imaging), antitumor therapy (e.g., photothermal therapy, photodynamic therapy, sonodynamic therapy, and immunotherapy), antimicrobial therapy, and anti-oxidative stress therapy. More importantly, the existing challenges of SAzymes are discussed, such as metal atom clustering and active site loss, ligand bond breakage at high temperature, insufficient environment tolerance, biosecurity risks, and limited catalytic long-term stability. Finally, several innovative strategies to address these stability concerns are proposed—synthesis process optimization (space-limited strategy, coordination site design, bimetallic synergistic strategy, defect engineering strategy, atom stripping-capture), surface modification, and dynamic responsive design—that collectively pave the way for robust, clinically viable SAzymes.

Glioblastoma (GBM) is the most aggressive tumor of the central nervous system and remains universally lethal due to lack of effective treatment options and their inefficient delivery to the brain. Here the development of multifunctional polymeric nanoparticles (NPs) for effective treatment of GBM is reported. The NPs are synthesized using a novel glutathione (GSH)‐reactive poly (2,2″‐thiodiethylene 3,3″‐dithiodipropionate) (PTD) polymer and engineered for brain penetration through neutrophil elastase‐triggered shrinkability, iRGD‐mediated targeted delivery, and lexiscan‐induced autocatalysis. It is found that the resulting lexiscan‐loaded, iRGD‐conjugated, shrinkable PTD NPs, or LiPTD NPs, efficiently penetrate brain tumors with high specificity after intravenous administration. Furthermore, it is demonstrated that LiPTD NPs are capable of efficient encapsulation and delivery of chemotherapy doxorubicin and sonosensitizer chlorin e6 to achieve combined chemotherapy and sonodynamic therapy (SDT). It is demonstrated that the capability of GSH depletion of LiPTD NPs further augments the tumor cell killing effect triggered by SDT. As a result, treatment with LiPTD NPs effectively inhibits tumor growth and prolongs the survival of tumor‐bearing mice. This study may suggest a potential new approach for effective GBM treatment. Glutathione (GSH)‐reactive polymer‐based nanoparticles (NPs), which can target drug delivery to the brain tumor through the integration of neutrophil elastase‐triggered shrinkability, ligand‐mediated interaction, and lexiscan‐induced blood–brain barrier modulation. The resulting NPs with excellent penetration capability can efficiently deliver chemotherapy drug doxorubicin and sonosensitizer chlorin e6 to tumors in the brain for effective chemo‐sonodynamic combination therapy.

Ischemia–reperfusion is a rapidly evolving cascade that involves a variety of metabolic shifts whose precise timing and sequential order are still poorly understood. Clarifying these dynamics is critical for understanding the core injury trajectory of stroke and for refining time-delimited therapeutic interventions. More broadly, continuous in situ monitoring of the middle-cerebral-artery occlusion process at the system level has not yet been achieved. Here, we report the first single-subject high-resolution spatiotemporal resolution metabolic maps of the ultra-early phase of ischemic stroke in a rodent model. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) imaging mapped a metabolic abnormality area in the ischemic hemisphere that propagates from the striatum to the cortex. Microdialysis probes were then stereotaxically implanted within this metabolic abnormality area, capturing 10,429 metabolites that resolved into 16 temporally distinct trajectories aligned with probe insertion, ischemic injury, and reperfusion injury. Analysis of specific metabolic pathways mainly revealed that the delayed clearance of metabolic waste (urea and tryptamine) during early reperfusion, the transient attenuation of the citrate-to-oxaloacetate buffering gradient within the TCA cycle, and the accumulation of extracellular branched-chain amino acids all play crucial roles in shaping the injury trajectory. Simultaneously, the depletion of cellular repair mechanisms (pyrimidine synthesis) in the early phase of reperfusion also warrants our attention. These findings provide novel insights into the molecular basis and mechanisms of ischemia–reperfusion and offer a comprehensive resource for further investigation.

Diffuse large B-cell lymphoma (DLBCL), accounting for 31% of non-Hodgkin lymphomas, remains recalcitrant to conventional therapies due to chemoresistance, metastatic progression, and immunosuppressive microenvironments. We report a novel injectable Fe3O4@DMSA@Pt@PLGA-PEG-PLGA hydrogel system integrating magnetothermal therapy (MHT), chemodynamic therapy (CDT), and immunomodulation. Under alternating magnetic fields (AMF), the system achieves rapid therapeutic hyperthermia (50 °C within 7 min) while activating pH/temperature-dual responsive peroxidase (POD) -like activity in Fe3O4@DMSA@Pt nanoparticles. Catalytic efficiency under tumor-mimetic conditions was significantly higher than Fe3O4@DMSA controls, generating elevated reactive oxygen species (ROS). Flow cytometry revealed 75.9% apoptotic cell death in A20 lymphoma cells at 50 °C, significantly surpassing CDT alone (24.5%). Importantly, this dual mechanism induced immunogenic cell death (ICD) characterized by 4.1-fold CRT externalization, 68% HMGB1 nuclear depletion, and 40.74 nM ATP secretion. This triggered robust dendritic cell maturation (92% CD86+/CD80+ DCs comparable to LPS controls) and T cell activation (16.9% CD25+/CD69+ ratio, 130-fold baseline). Our findings validate the therapeutic potential of magnetothermal-chemodynamic synergy for DLBCL treatment, paving the way for innovative multi-mechanism therapeutic strategies against DLBCL with potential clinical translation prospects.

Tumor whole-cell vaccines are designed to introduce a wide range of tumor-associated antigens into the body to counteract the immunosuppression caused by tumors. In cases of lymphoma of which the specific antigen is not yet determined, the tumor whole-cell vaccine offers distinct advantages. However, there is still a lack of research on an effective preparation method for the lymphoma whole-cell vaccine. To solve this challenge, we prepared a whole-cell vaccine derived from non-Hodgkin B-cell lymphoma (A20) via the photothermal effect mediated by Prussian blue nanoparticles (PBNPs). The immune activation effect of this vaccine against lymphoma was verified at the cellular level. The PBNPs-treated A20 cells underwent immunogenic cell death (ICD), causing the loss of their ability to form tumors while retaining their ability to trigger an immune response. A20 cells that experienced ICD were further ultrasonically crushed to prepare the A20 whole-cell vaccine with exposed antigens and enhanced immunogenicity. The A20 whole-cell vaccine was able to activate the dendritic cells (DCs) to present antigens to T cells and trigger specific immune responses against lymphoma. Whole-cell vaccines are primarily administered through direct injection, a method that often results in low delivery efficiency and poor patient compliance. Comparatively, the microneedle patch system provides intradermal delivery, offering enhanced lymphatic absorption and improved patient adherence due to its minimally invasive approach. Thus, we developed a porous microneedle patch system for whole-cell vaccine delivery using Gelatin Methacryloyl (GelMA) hydrogel and n-arm-poly(lactic-co-glycolic acid) (n-arm-PLGA). This whole-cell vaccine combined with porous gel microneedle patch delivery system has the potential to become a simple immunotherapy method with controllable production and represents a promising new direction for the treatment of lymphoma.

Cancer targeting nanoprobes with precisely designed physicochemical properties may show enhanced pharmacological targeting and therapeutic efficacy. As a widely used commercialized antibody, rituximab has been in clinical use for three decades and has lengthened or even saved thousands of lives. However, many people cannot benefit from rituximab treatment because of drug resistance or side effects. In this study, a 13-nm rituximab-conjugated magnetic nanoparticle was developed as a therapeutic nanoprobe targeting CD20 overexpressing malignant lymphoma cells to enhance the treatment effects of rituximab. The magnetic cores (2,3-dimercaptosuccinicacid modified Fe O nanoparticles, Fe O @DMSA) of the nanoprobes with an average diameter of 6.5 nm were synthesized using a co-precipitation method. Rituximab was then conjugated on the surface of Fe O @DMSA using a cross-linking agent (carbodiimide/N-hydroxysulfosuccinimide sodium salt). Based on theoretical calculations, approximately one antibody was coupled with one nanoparticle, excluding the multivalent antibody effect. Cell targeting experiments and magnetic resonance (MR) signal and T2 measurements showed that the Fe O @DMSA@Ab nanoprobes have specific binding affinity for CD20-positive cells. Compared to rituximab and Fe O @DMSA, Fe O @DMSA@Ab nanoprobes significantly reduced cell viability and promoted Raji cell apoptosis. Initiating events of apoptosis, including increased intracellular calcium and reactive oxygen species, were observed in nanoprobe-treated Raji cells. Nanoprobe-treated Raji cells also showed the most drastic decrease in mitochondrial membrane potential and Bcl-2 expression, compared to rituximab and Fe O @DMSA-treated Raji cells. These results indicate that Fe O @DMSA@Ab nanoprobes have the potential to serve as MRI tracers and therapeutic agents for CD20-positive cells.

Extracellular vesicle (EV) microRNAs (miRNAs) are promising liquid biopsy biomarkers for non‐invasive diagnosis, monitoring, and therapeutic evaluation of cancer. However, sensitive EV miRNA detection is hindered by complex pre‐analytical processing. Here, the authors present an anionic liposome (AL) assisted membrane fusion strategy enabling one‐step multiplexed quantification of EV miRNAs directly from plasma without EV isolation or RNA extraction, termed EValarm (Anionic Liposome Assisted miRNAs Monitoring for Extracellular Vesicles). Liposomes encapsulating probes are prepared using a microfluidic chip, achieving catalytic signal amplification after target recognition of miRNA. Systematic lipid screening identified ALs as optimal carriers, exhibiting minimal background and superior sensitivity compared to cationic and neutral liposomes. The AL‐based assay delivered accuracy comparable to quantitative PCR with a streamlined workflow. Applied to 106 clinical samples from lymphoma patients and healthy controls, integration with artificial intelligence achieved high accuracy (AUC > 0.99). In summary, this study demonstrates a platform enabling direct and sensitive plasma EV miRNA detection, offering strong potential for clinical translation in cancer liquid biopsy. A novel strategy for in situ multiplexed miRNA analysis of plasma extracellular vesicles (EValarm) has been developed. EValarm enables straightforward detection of different extracellular vesicle miRNAs from plasma samples through systematic screening of liposome surface charges, without requiring complex pretreatment steps, and achieves satisfactory accuracy in lymphoma patient detection in combination with artificial intelligence analysis.