Search

[Display omitted] In tumor therapy, copper (Cu)-based nanozymes with peroxidase-like activity play a crucial role in converting hydrogen peroxide into hydroxyl radicals (OH). This process induces immunogenic cell death, which in turn activates the body's immune response, enhancing the efficacy of tumor immunotherapy. Nonetheless, the efficiency of this reaction is curtailed due to the oxidation of Cu(I) to Cu(II), leading to the self-depletion of the nanozyme's activity and an insufficient yield of OH for effective immunotherapeutic activation. To surmount this challenge, our research introduces a photocharging self-doped semiconductor nanozyme, copper sulfide (Cu 9 S 8). The photocharging effect enables the nanozyme to convert internal Cu(II) back to Cu(I) through charge transfer induced by near-infrared (NIR)-II photothermal energy, thereby effectively maintaining the enzyme-like activity of the nanozyme. Additionally, Cu 9 S 8 is enhanced with a calcium sulfide (CaS) coating. This coating reacts in the acidic microenvironment of tumors to generate hydrogen sulfide (H 2 S) gas, which in turn suppresses the catalase activity inherent in tumor cells, ensuring a plentiful supply of H 2 O 2 for the nanozyme's operation. This dual strategy of amplifying enzyme-like activity and substrate availability culminates in the generation of ample OH within tumor cells, leading to significant immunogenic cell death and thereby realizing potent immunotherapy. [ABSTRACT FROM AUTHOR]

Many studies relating to the preparation of magnetic composites from various raw materials have been reported. However, for the first time, the magnetic Fe‐decorated carbon nanosheets (FeCNs) were prepared using waste facemasks with iron‐containing nose strip as both carbon source and iron source. The uniform decoration of Fe3O4 nanoparticles not only endows carbon matrix with magnetic separation property but also enriches the lamellar structure to furnish more catalytically active sites. The as‐prepared FeCNs nanozymes behave optimal peroxidase‐like activity under pH of 4 and temperature of 50°C, excellent reusability, and substrate affinity. Based on FeCNs, a convenient colorimetric strategy was successfully constructed for flavonoid detection in simulated and real samples. Experimental and theoretical results show that hydroxyl radicals (•OH) and superoxide radical (•O2−) are the major active species in the reactions that are catalyzed by FeCNs in the presence of H2O2. And the generation of these radicals can be attributed to the electron transfer between Fe2+/Fe3+ pairs and H2O2 molecules. This work provides a new way for preparing magnetic carbon‐based nanozymes and realizes the resource utilization of waste facemasks. [ABSTRACT FROM AUTHOR]

The practical usage of natural enzymes is limited due to their sensitivity and need for special conditions. On the other hand, nanozymes provide robust catalytic performance, high stability in challenging conditions, economical production, and versatile surface modification. With these benefits, nanozymes surpass the constraints of natural enzymes and are a better option for a range of applications. Iron oxide-based nanomaterials have attracted significant attention due to their distinctive properties, such as catalase-like function under pH seven and peroxidase enzyme activity at acrid pH values as well as higher enzyme-like activities. This study has explored how synthesis procedures have advanced recently, presenting creative approaches with increased stability, regulated particle sizes, and catalytic activities. The potential of iron oxide nanozymes in a range of domains, such as healthcare, hyperthermia, MRI, optical devices, and anticancer activity, has also been investigated. This critical study provides a comprehensive overview of the synthesis, characterization, and potential uses of iron oxide-based nanozymes, identifies the areas where research is currently lacking, and makes options for future directions to maximize its potential in medicine. Overall, this review expands our understanding of iron oxide nanozymes and is a helpful resource for scientists creating novel medicinal and diagnostic tools. [ABSTRACT FROM AUTHOR]

The significance of the tumor microenvironment (TME) in tumor initiation and progression is increasingly acknowledged. Conventional therapeutic approaches face limitations within the complex TME, including the restrictions imposed by hypoxia on photodynamic therapy (PDT) and the deficiency of endogenous H₂O₂ affecting chemodynamic therapy (CDT). In response to the TME's characteristics of high metabolism, hypoxia, and weak acidity, a multifunctional nanosystem MNPs/GOD@CS/IR820, which synergistically integrates CDT and PDT, has been developed. This system can actively accumulate at tumor sites under an external magnetic field and release active components in response to the weakly acidic TME. It mitigates the limitations imposed by hypoxia and endogenous H₂O₂ deficiency on PDT and CDT, respectively, thereby enabling synergistic treatment. Additionally, the system's multimodal imaging capabilities facilitate precise tumor localization and real-time, non-invasive in vivo assessment via fluorescence imaging and MRI. In vitro and in vivo evaluations demonstrate significant antitumor efficacy, effectively inhibiting tumor growth and improving survival rates. By comprehensively addressing the challenges posed by the complex TME and enhancing real-time monitoring capabilities, our nanosystem paves the way for personalized and precise cancer treatment. This study introduces an innovative MNPs/GOD@CS/IR820 nanosystem that represents a significant advancement in cancer nanomedicine by addressing critical limitations of conventional photodynamic therapy (PDT), particularly in hypoxic tumor microenvironments. By synergistically integrating chemodynamic therapy (CDT) with PDT and incorporating MRI and fluorescence dual-modal imaging capabilities, this multifunctional platform offers enhanced therapeutic efficacy and real-time monitoring. The system's ability to generate oxygen in situ overcomes hypoxia-induced limitations, while its multimodal mechanism of action induces tumor cell apoptosis through multiple pathways. In vitro and in vivo studies demonstrate remarkable antitumor efficacy across diverse cancer types, significantly inhibiting tumor growth and improving survival rates. This comprehensive approach to cancer diagnosis and treatment not only advances precision medicine for targeted, multimodal cancer management but also provides a promising foundation for future clinical applications, potentially transforming cancer treatment strategies and improving patient outcomes. [Display omitted] [ABSTRACT FROM AUTHOR]

Nanozymes are nanomaterials with mimetic enzyme properties and the related research has attracted much attention. It is of great value to develop methods to construct nanozymes and to study their application in bioanalysis. Herein, the metal–ligand cross-linking strategy was developed to fabricate superstructure nanozymes. This strategy takes advantage of being easy to operate, adjustable, cheap, and universal. The fabricated superstructure nanozymes possess efficient peroxidase-like catalytic activity. The enzyme reaction kinetic tests demonstrated that for TMB and H2O2, the Km is 0.229 and 1.308 mM, respectively. Furthermore, these superstructure nanozymes are applied to highly efficient and sensitive detection of glucose. The linear range for detecting glucose is 20–2000 μM, and the limit of detection is 17.5 μM. Furthermore, mechanistic research illustrated that this integrated system oxidizes glucose to produce hydrogen peroxide and further catalyzes the production of ·OH and O2·–, which results in a chromogenic reaction of oxidized TMB for the detection of glucose. This work could not only contribute to the development of efficient nanozymes but also inspire research in the highly sensitive detection of other biomarkers. [ABSTRACT FROM AUTHOR]

Nanozymes are a class of nanomaterials with biocatalytic function and enzyme-like activity, whose advantages include high stability, low cost, and mass production. They can catalyze the substrates of natural enzymes based on specific nanostructures and serve as substitutes for natural enzymes. Their applied research involves a wide range of fields such as biomedicine, environmental governance, agriculture, and food. Molecular logic gates are a new cross-disciplinary discipline, which can simulate the function of silicon circuits on a molecular scale, perform single or multiple input logic operations, and generate logic outputs. A molecular logic gate is a binary operation that converts an input signal into an output signal according to the rules of Boolean logic, generating two signals, a high level, and a low level. The high and low levels represent the "true" and "false" values of the logic gates, and their outputs correspond to "l" and "0" of the molecular logic gates, respectively. The combination of nanozymes and logic gates is a novel and attractive research direction, and the cross-application of the two brings new opportunities and ideas for various fields, such as the construction of efficient biocomputers, intelligent drug delivery systems, and the precise diagnosis of diseases. This review describes the application of logic gates based on nanozymes, which is expected to provide a certain theoretical foundation for researchers' subsequent studies. [ABSTRACT FROM AUTHOR]

The high catalytic activity of Cu-based nanozymes mainly depends on the efficient Fenton-like reaction of Cu+/ H2O2, but Cu+ cannot exist stably. Trying to find a material that can stably support Cu+ while promoting the electron cycle of Cu2+/Cu+ still faces serious challenges. C60 is expected to be an ideal candidate to solve this problem due to its unique structure and rich physicochemical properties. Here, we designed and synthesized a C60-doped Cu+-based nanozyme (termed as C60-Cu-Bpy) by loading high catalytic active site Cu+ onto C60 and coordinating with 2,2′-bipyridine (Bpy). The single crystal diffraction analysis and a series of auxiliary characterization technologies were used to demonstrate the successful preparation of C60-Cu-Bpy. Significantly, the C60-Cu-Bpy exhibited superior peroxidase-like activity during the catalytic oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB). Then, the catalytic mechanism of C60-Cu-Bpy as peroxidase was elucidated in detail, mainly benefiting from the dual function of C60. On the one hand, C60 acted as a carrier to directly support Cu+, which has the ability to efficiently decompose H2O2 to produce reactive oxygen species. The other was that C60 acted as an electron buffer, contributing to promoting the Cu2+/Cu+ cycle to facilitate the reaction. Furthermore, a colorimetric sensor for the quantitative analysis of bleomycin was established based on the principle of bleomycin specific inhibition of C60-Cu-Bpy peroxidase-like activity, with satisfactory results in practical samples. This study provides a new strategy for the direct synthesis of Cu+-based nanozymes with high catalytic performance. Schematic illustration of the preparation of C60-Cu-Bpy (a) and the colorimetric detection of bleomycin based on specific inhibition of C60-Cu-Bpy peroxidase-like activity (b) [ABSTRACT FROM AUTHOR]

Implant‐related infections are characterized by the formation of bacterial biofilms. Current treatments have various drawbacks. Nanozymes with enzyme‐like activity can produce highly toxic substances to kill bacteria and remove biofilms without inducing drug resistance. However, it is difficult for current monometallic nanozymes to function well in complex biofilm environments. Therefore, the development of multimetallic nanozymes with efficient multienzyme activities is crucial. In the present study, bimetallic nanozyme, ZnO‐CuS nanoflowers with peroxidase (POD), glutathione oxidase (GSH‐Px), and catalase (CAT) activity are successfully synthesized via calcination and loaded into F127 hydrogels for the treatment of implant‐related infections. The ability of ZnO‐CuS nanoflowers to bind bacteria is key for efficient antimicrobial activity. In addition, ZnO‐CuS nanoflowers with H2O2 disrupt the metabolism of MRSA, including arginine synthesis, nucleotide excision repair, energy metabolism, and protein synthesis. ZnO‐CuS/F127 hydrogel in combination with H2O2 has been demonstrated to be effective in clearing biofilm infection and facilitating the switch of M1 macrophages to M2‐repairative phenotype macrophages for the treatment of implant infections in mice. Furthermore, ZnO‐CuS/F127 hydrogels have favorable biosafety, and their toxicity is negligible. ZnO‐CuS/F127 hydrogel has provided a promising biomedical strategy for the healing of implant‐related infections, highlighting the potential of bimetallic nanozymes for clinical applications. [ABSTRACT FROM AUTHOR]

As novel multifunctional materials that merge enzyme-like capabilities with the distinctive traits of nanomaterials, nanozymes have made significant strides in interdisciplinary research areas spanning materials science, bioscience, and beyond. This article, for the first time, employed bibliometric methods to conduct an in-depth statistical analysis of the global nanozymes research and demonstrate research progress, hotspots and trends. Drawing on data from the Web of Science Core Collection database, we comprehensively retrieved the publications from 2004 to 2024. The burgeoning interest in nanozymes research across various nations indicated a growing and widespread trend. This article further systematically elaborated the enzyme-like activities, matrix, multifunctional properties, catalytic mechanisms and various applications of nanozymes, and the field encounters challenges. Despite notable progress, and requires deeper exploration guide the future research directions. This field harbors broad potential for future developments, promising to impact various aspects of technology and society. [ABSTRACT FROM AUTHOR]

Enzymes play a significant role in mediating inflammatory and immune responses in periodontitis. Effective diagnosis, timely treatment, and continuous management of periodontal enzymes are essential to prevent undesirable consequences; however, this remains a significant challenge. Nanoparticles (NPs) have attracted significant attention in biomedicine because of their advantageous nanosized effects. NPs are conjugated with specific enzyme substrates at responsive sites that are triggered by periodontitis enzyme biomarkers, leading to functional or characteristic changes. In contrast, NPs with enzyme-mimetic activities exhibit catalytic activity, effectively destroying pathogenic biofilms and modulating the immune response in periodontitis. The unique properties of enzyme-targeting NPs have enabled the development of biosensors and fluorescent probes capable of identifying enzyme biomarkers associated with periodontitis. Enzyme-responsive and enzyme-mimetic NPs both exert therapeutic applications in the treatment of periodontitis. In this review, we provide a comprehensive overview of the enzymes associated with periodontitis, the mechanisms of enzyme-responsive and enzyme-mimetic NPs, recent advancements in the use of NPs for detecting these enzymes, and the therapeutic applications of NPs in targeting or mimicking enzyme functions. We also discuss the challenges and prospects of using NPs in the diagnosis and treatment of periodontitis. [ABSTRACT FROM AUTHOR]

Mitochondria are crucial sites for biological oxidation and substance metabolism and plays a vital role in maintaining intracellular homeostasis. When mitochondria undergo oxidative damage or dysfunction, they can harm the organism, leading to various reactive oxygen species (ROS)-related diseases. Therefore, therapies targeting mitochondria are a strategy for treating multiple diseases. Many nanozymes can mimic antioxidant enzymes, which enables them to eliminate ROS to mitigate mitochondrial dysfunction. The therapeutic approaches and drugs targeting the mitochondrial electron transport chain (ETC) have emerged as effective treatments for oxidative stress-related diseases resulting from mitochondrial respiratory chain disorders. Therefore, nanozymes that can regulate homeostasis in the mitochondrial ETC have emerged as effective therapeutic agents for treating oxidative stress-related diseases. In addition, benefit from the controllability and modifiability of nanozymes, their modification with TPP, SS-31 peptide, and mitochondrial permeability membrane peptide to eliminate ROS and repair mitochondrial function. The nanozymes that specifically target mitochondria are powerful tools for the treatment of ROS-associated disorders. We discussed the design strategies pertaining to mitochondrion-targeted nanozymes to treat various diseases to develop more efficacious nanozyme tools for the treatment of ROS-related diseases in the future. • The therapies targeting mitochondria are a strategy for treating multiple ROS-related diseases. • Nanozymes has antioxidant enzyme activity, which can eliminate ROS to alleviate mitochondrial dysfunction. • Nanozymes are controllable and modifiable, which enables them to target mitochondria. • We present recent advancements in the design strategies of mitochondria-repairing nanozymes for the treatment of diseases. [ABSTRACT FROM AUTHOR]

Current microbial control strategies face challenges in keeping up with the escalation of microbial problems due to the presence of biofilms. Therefore, there is an urgent need to develop effective and robust strategies to control problematic biofilms in water treatment and reuse systems. Nanozymes, which have intrinsic biocatalytic activity and broad antibacterial spectra, hold promise for controlling resilient biofilms. This review summarizes the milestones of nanozyme studies and their applications as antibiofilm agents. The mechanisms behind the antibacterial, quorum quenching, and depolymerizing properties of nanozymes with different enzyme activities are discussed. Notably, the surface and composition of nanozymes are crucial for their efficacy in biofilm control; thus, rationally designed nanozymes can increase their effectiveness. Additionally, the challenges of nanozymes as antibiofilm agents in realistic scenarios are investigated along with proposed strategies to overcome these challenges. Prospects of nanozyme-based biofilm control, such as machine learning-assisted nanozyme design, are also discussed. Overall, this review highlights the potential of nanozymes as antibiofilm agents and provides insights into the future design of nanozymes for biofilm control. [ABSTRACT FROM AUTHOR]

Nanotechnology is an emerging area of science that deals with making and designing of nanosized objects having widespread applications. Nanomaterials or nanosized objects have that have at least one dimension in the nanoscale range. Nanozymes are enzymes or nanomaterials showing enzyme-like properties. Nanozymes have similar advantages that are associated with other nanomaterials, too. Nanozymes have combined properties of nanomaterials as well as enzymes, they are capable of leading innovations in science and medicine, and their utility has been demonstrated by the emergence of large number of nanotechnology-based products in the modern scenario for disease prevention and diagnosis. Many of the products utilize enzyme-mimicking properties of the nanozymes besides their other properties. But they do have their limitations and disadvantages. The present review focuses on the diverse potential uses of this newly identified group of enzymes with specific reference to their applications in tackling various aspects of coronavirus disease 2019 (COVID-19). [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nanozymes are nanomaterials that exhibit enzyme-like catalytic activity, which have drawn increasing attention on account of their unique superiorities including very high robustness, low cost, and ease of modification. Metal–organic frameworks (MOFs) and covalent–organic frameworks (COFs) have emerged as promising candidates for nanozymes due to their abundant catalytic activity centers, inherent porosity, and tunable chemical functionalities. In this review, we first compare the enzyme-mimicking activity centers and catalytic mechanisms between MOF and COF nanozymes, and then summarize the recent research on designing and modifying MOF and COF nanozymes with inherent catalytic activity. Moreover, typical examples of sensing applications based on these nanozymes are presented, as well as the translation of enzyme catalytic activity into a visible signal response. At last, a discussion of current challenges is presented, followed by some future prospects to provide guidance for designing nanozyme sensors based on MOFs and COFs for practical applications. [ABSTRACT FROM AUTHOR]

Bacterial infections are a growing problem, and antibiotic drugs can be widely used to fight bacterial infections. However, the overuse of antibiotics and the evolution of bacteria have led to the emergence of drug-resistant bacteria, severely reducing the effectiveness of treatment. Therefore, it is very important to develop new effective antibacterial strategies to fight multi-drug resistant bacteria. Nanozyme is a kind of enzyme-like catalytic nanomaterials with unique physical and chemical properties, high stability, structural diversity, adjustable catalytic activity, low cost, easy storage and so on. In addition, nanozymes also have excellent broad-spectrum antibacterial properties and good biocompatibility, showing broad application prospects in the field of antibacterial. In this paper, we reviewed the research progress of antibacterial application of nanozymes. At first, the antibacterial mechanism of nanozymes was summarized, and then the application of nanozymes in antibacterial was introduced. Finally, the challenges of the application of antibacterial nanozymes were discussed, and the development prospect of antibacterial nanozymes was clarified. [ABSTRACT FROM AUTHOR]

The treatment of solid tumors remains a significant challenge due to the complex, immunosuppressive tumor microenvironment (TME). This manuscript introduces the self‐oxygenated biomimetic nanozyme system, SS‐MSN@Au‐BOM, which innovatively combines catalytic therapy with immunotherapy to modulate the TME for enhanced therapeutic efficacy. Employing mesoporous silicon nanoparticles doped with disulfide bonds, the system integrates gold nanozymes that exhibit glucose oxidase (GOx)‐like and peroxidase (POD)‐like activities, along with a catalase (CAT) function derived from bacterial outer membrane (BOM) coatings. SS‐MSN@Au‐BOM significantly disrupted tumor growth by catalyzing endogenous hydrogen peroxide to generate cytotoxic ROS and essential oxygen, enhancing intratumoral ROS levels while alleviating hypoxia. This catalytic action facilitates immunogenic cell death, enhances dendritic cell maturation, and T‐cell activation. Notably, the system shows excellent biocompatibility, effective tumor targeting, and prolonged systemic circulation. SS‐MSN@Au‐BOM offers a dual‐functional approach that effectively disrupts the TME and promotes robust antitumor immunity. This study paves the way for further clinical investigation and the development of enzyme‐based therapeutics, potentially transforming the landscape of cancer treatment. [ABSTRACT FROM AUTHOR]

As the pathophysiological basis of type 2 diabetes mellitus (T2DM), insulin resistance (IR) is closely related to oxidative stress (OS) and inflammation, while nanozymes have a good therapeutic effect on inflammation and OS by scavenging reactive oxygen species (ROS). Hence, AuCePt porous hollow cascade nanozymes (AuCePt PHNs) are designed by integrating the dominant enzymatic activities of three metallic materials, which exhibit superior superoxide dismutase/catalase-like activities, and high drug loading capacity. In vitro experiments proved that AuCePt PHNs can ultra-efficiently scavenge endogenous and exogenous ROS. Moreover, AuCePt PHNs modified with lactobionic acid (LA) and loaded with disulfiram (DSF), named as AuCePt PHNs-LA@DSF, can significantly improve glucose uptake and glycogen synthesis in IR hepatocytes by regulating the insulin signaling pathways (IRS-1/AKT) and gluconeogenesis signaling pathways (FOXO-1/PEPCK). Intravenous administration of AuCePt PHNs-LA@DSF not only showed high liver targeting efficiency, but also reduced body weight and blood glucose and improved IR and lipid accumulation in high-fat diet-induced obese mice and diabetic ob/ob mice. This research elucidates the intrinsic activity of AuCePt PHNs for cascade scavenging of ROS, and reveals the potential effect of AuCePt PHNs-LA@DSF in T2DM treatment. [ABSTRACT FROM AUTHOR]

Comprehensive Summary Real‐time on‐site monitoring of resorcinol (RS) concentrations is crucial for detecting hazardous levels, enabling prompt response measures to mitigate potential environmental and health risks. In this study, we developed an innovative method using CoNi@CN‐2 nanozymes to activate peroxymonosulfate (PMS) for oxidizing 3,3',5,5'‐tetramethylbenzidine (TMB). Our results show that the formation of Ni2+ through the oxidation of Ni0 on the CoNi@CN‐2 surface significantly enhances the electron‐donating capacity of Co0. The catalytic reaction of TMB is mediated by redox active species (SO4•−, •O2−, •OH and 1O2). RS drives colorimetry by transferring electrons to the benzene ring and specific nitrogen atoms in ox‐TMB, reducing ox‐TMB to TMB. Furthermore, the colorimetric assay shows a robust linear correlation between RS concentration and absorbance (Abs), described by Abs = –0.44[RS] + 0.886 (0—200 μmol/L, R2 = 0.983). Also, we introduce a novel smartphone‐integrated autonomous detection software that can analyze RS concentration and grayscale values (GSV), yielding GSV = 0.327[RS] + 63.601 (0—200 μmol/L, R2 = 0.990) with a detection limit of 5.29 μmol/L. Additionally, excess PMS leads to ROS attacking specific sites in ox‐TMB, forming secondary oxidation products. This study has enabled rapid and accurate detection of RS, making a significant contribution to environmental safety and protection. [ABSTRACT FROM AUTHOR]

ABSTRACT Metal–organic framework (MOF) nanozymes have garnered widespread attention in the field of biomimetic catalysis due to their highly controllable porous structure and surface functionalization, enabling them to mimic the catalytic activity and specificity of natural enzymes while offering greater stability and reusability. In recent years, significant progress has been made in the theoretical computation studies of MOF nanozymes' catalytic reactions, providing deep insights into their catalytic and analytical mechanisms. This review comprehensively gathers the latest research progress of theoretical calculation–driven MOF nanozymes on their catalytic mechanisms and applications. First, the methods that can be used for theoretical calculations of MOF nanozymes, especially density functional theory (DFT), are reviewed to help deeply analyze the active site distribution, electron transfer pathways, and adsorption and activation mechanisms of reactants of MOF nanozymes. Subsequently, this review deeply studies the contribution of these theoretical calculation methods to revealing the catalytic reaction mechanism of MOF nanozymes (such as active sites and enzyme‐like activity), especially the specific role of electron transfer and reaction energy changes in key reaction steps. Finally, this review looks forward to the challenges and opportunities in the theoretical computation for the future design and application of MOF nanozymes, especially in accurately predicting catalytic activities, understanding complex reaction mechanisms, and guiding the synthesis of new nanozyme materials. By integrating theoretical calculations with experimental research, the study of MOF nanozymes is expected to forge new avenues in biomimetic catalysis and provide effective strategies for addressing challenges in the fields of sensing, biomedicine, and environmental protection. [ABSTRACT FROM AUTHOR]

Engineering multimetallic nanocatalysts with the entropy‐mediated strategy to reduce reaction activation energy is regarded as an innovative and effective approach to facilitate efficient heterogeneous catalysis. Accordingly, conformational entropy‐driven high‐entropy alloys (HEAs) are emerging as a promising candidate to settle the catalytic efficiency limitations of nanozymes, attributed to their versatile active site compositions and synergistic effects. As proof of the high‐entropy nanozymes (HEzymes) concept, elaborate PdMoPtCoNi HEA nanowires (NWs) with abundant active sites and tuned electronic structures, exhibiting peroxidase‐mimicking activity comparable to that of natural horseradish peroxidase are reported. Density functional theory calculations demonstrate that the enhanced electron abundance of HEA NWs near the Fermi level (EF) is facilitated via the self‐complementation effect among the diverse transition metal sites, thereby boosting the electron transfer efficiency at the catalytic interface through the cocktail effect. Subsequently, the HEzymes are integrated with a portable electronic device that utilizes Internet of Things‐driven signal conversion and wireless transmission functions for point‐of‐care diagnosis to validate their applicability in digital biosensing of urinary biomarkers. The proposed HEzymes underscore significant potential in enhancing nanozymes catalysis through tunable electronic structures and synergistic effects, paving the way for reformative advancements in nano‐bio analysis. [ABSTRACT FROM AUTHOR]

Filling of oxygen vacancies in manganese-oxide nanosheets with Pt single-atoms or nanoparticles yields nanozymes with high catalytic activity. Catalytic activity depended on the diameter of the Pt nanoparticles used for loading the nanosheet. Pt nanoparticles with intermediate diameters (3.0 nm), possessing well-developed (1 1 1) crystal planes, yielded equal catalytic activities as Pt single-atoms. [Display omitted] • Manganese-oxide nanosheets loaded with Pt single-atoms or Pt nanoparticles are compared. • Sheets with Pt single-atoms or 3.0 nm diameter Pt nanoparticles have high catalytic activities. • 1.5 nm Pt nanoparticles do not possess well-developed, highly reactive (1 1 1) crystal planes. • 7 nm Pt nanoparticles coalesce on a nanosheet, changing the Mn oxidation state. • Under-sized (1.5 nm) and over-sized Pt (7.0 nm) nanoparticles yield lower catalytic activity. Hybrid-nanozymes are promising in various applications, but comprehensive comparison of hybrid-nanozymes composed of single-atoms or nanoparticles on the same support has never been made. Here, manganese-oxide nanosheets were loaded with Pt-single-atoms or differently-sized nanoparticles and their oxidase- and-peroxidase activities compared. High-resolution Transmission-Electron-Microscopy and corresponding Fast Fourier Transform imaging showed that Pt-nanoparticles (1.5 nm diameter) had no clear (1 1 1) crystal-planes, while larger nanoparticles had clear (1 1 1) crystal-planes. X-ray Photo-electron Spectroscopy demonstrated that unloaded nanosheets were composed of MnO 2 with a high number of oxygen vacancies (V o /Mn 0.4). Loading with 7.0 nm Pt-nanoparticles induced a change to Mn 2 O 3 , while loading with 1.5 nm nanoparticles increased the number of vacancies (V o /Mn 1.2). Nanosheets loaded with 3.0 nm Pt-nanoparticles possessed similarly high catalytic activities as Pt-single-atoms. However, loading with 1.5 nm or 7.0 nm Pt-nanoparticles yielded lower catalytic activities. A model is proposed explaining the low catalytic activity of under- and over-sized Pt-nanoparticles as compared with intermediately-sized (3.0 nm) Pt-nanoparticles and single-atoms. Herewith, catalytic activities of hybrid-nanozymes composed of single-atoms and intermediately-sized nanoparticles are put a par , as confirmed here with respect to bacterial biofilm eradication. This conclusion facilitates a balanced choice between using Pt-single-atoms or nanoparticles in further development and application of hybrid-nanozymes. [ABSTRACT FROM AUTHOR]

Hydrophilicity‐hydrophobicity modulation of active sites provides a promising strategy for enhancing catalytic performance. Current researches focus on the influence of substrate molecules, however, the role of H2O molecules is often overlooked in nanozyme‐catalyzed reactions. Herein, bioinspired Pt@ZIF‐R (R = ‐90, ‐8, ‐8@TMS, where TMS is tetraethoxysilane) nanozymes are designed as model catalysts, with Pt nanoparticles as active centers and metal organic‐framework nanocavities as hydrophilic‐hydrophobic binding pockets, revealing the critical role of H2O in the peroxidase‐like catalytic process of H2O2 decomposition. A positive correlation between catalytic activity and hydrophobicity is observed, and strong hydrophobic Pt@ZIF‐8@TMS nanozyme exhibits the best catalytic performance. Theoretical calculations indicate that as hydrophobicity increases, solvent H2O reduces the competitive adsorption with H2O2 and decreases the energy barrier of the rate‐determining step (2*O→*O2) simultaneously. In addition, the desorption of the product H2O is thermodynamically favorable with increasing hydrophobicity. Importantly, Pt@ZIF‐8@TMS nanozyme is successfully used to develop a colorimetric biosensor for the detection of organophosphorus pesticides, with a detection limit as low as 0.7 ng mL−1, which is superior to numerous existing methods. This work provides fundamental insights into the function of hydrophobicity in boosting catalytic activity, which may offer guidance for the development of efficient nanozymes. [ABSTRACT FROM AUTHOR]

Plants such as herbs, vegetables, fruits, and cereals are closely related to human life. Developing effective testing methods to ensure their safety and quantify their active components are of significant importance. Recently, nanomaterials with enzyme-like activity (known as nanozymes) have been widely developed in various assays, including colorimetric, fluorescence, chemiluminescence, and electrochemical analysis. This review presents the latest advances in analyzing phytochemicals and hazardous substances in plant samples based on nanozymes, including some active ingredients, organophosphorus pesticides, heavy metal ions, and mycotoxins. Additionally, the current shortcomings and challenges of the actual sample analysis were discussed. [ABSTRACT FROM AUTHOR]

Background: In diabetic wounds, hyperglycemia-induced cytotoxicity and impaired immune microenvironment plasticity directly hinder the wound healing process. Regulation of the hyperglycemic microenvironment and remodeling of the immune microenvironment are crucial. Results: Here, we developed a nanozymatic functionalized regenerative microenvironmental regulator (AHAMA/CS-GOx@Zn-POM) for the effective repair of diabetic wounds. This novel construct integrated an aldehyde and methacrylic anhydride-modified hyaluronic acid hydrogel (AHAMA) and chitosan nanoparticles (CS NPs) encapsulating zinc-based polymetallic oxonate nanozyme (Zn-POM) and glucose oxidase (GOx), facilitating a sustained release of release of both enzymes. The GOx catalyzed glucose to gluconic acid and (H₂O₂), thereby alleviating the effects of the hyperglycemic microenvironment on wound healing. Zn-POM exhibited catalase and superoxide dismutase activities to scavenge reactive oxygen species and H₂O₂, a by-product of glucose degradation. Additionally, Zn-POM induced M1 macrophage reprogramming to the M2 phenotype by inhibiting the MAPK/IL-17 signaling diminishing pro-inflammatory cytokines, and upregulating the expression of anti-inflammatory mediators, thus remodeling the immune microenvironment and enhancing angiogenesis and collagen regeneration within wounds. In a rat diabetic wound model, the application of AHAMA/CS-GOx@Zn-POM enhanced neovascularization and collagen deposition, accelerating the wound healing process. Conclusions: Therefore, the regenerative microenvironment regulator AHAMA/CS-GOx@Zn-POM can achieve the effective conversion of a pathological microenvironment to regenerative microenvironment through integrated control of the hyperglycemic-immune microenvironment, offering a novel strategy for the treatment of diabetic wounds. [ABSTRACT FROM AUTHOR]

Inflammatory infiltration of synovial M1 macrophages, high levels of ROS, and NO exacerbate osteoarthritis (OA) progression. The PdZn/CoSA‐NC nanozymes, which are highly ordered PdZn intermetallic nanoparticles loaded with Co single atom N‐doped carbon‐rich in multi‐level pores, in an attempt to serve as SOD and CAT mimicking nanozymes for OA therapy is designed. The PdZn/CoSA‐NC nanozymes' high electron transfer and dual active site sufficient exposure enhances free radical adsorption and lower reaction energies, accelerating SOD‐like, CAT‐like, and GPx‐like catalyzed reactions, outperforming CoSA‐NC and PdZn/NC alone. Furthermore, PdZn/CoSA‐NC nanozymes exhibit favorable biocompatibility, reduce synovial macrophage oxidative stress in OA, alleviate hypoxia, restore mitochondrial function, regulate energy metabolism, increase antioxidant factors, and reduce inflammatory factors, thus effectively mitigating the progression of OA. Mechanistically, PdZn/CoSA‐NC nanozymes downregulate M1‐type phenotypic markers like IL‐1β by regulating purine metabolism. The PdZn/CoSA‐NC nanozymes offer a novel approach to treating oxidative stress‐related inflammatory diseases. [ABSTRACT FROM AUTHOR]

Cascade reactions are described as efficient and versatile tools, and organized catalytic cascades can significantly improve the efficiency of chemical interworking between nanozymes. They have attracted great interest in many fields such as chromogenic detection, biosensing, tumor diagnosis, and therapy. However, how to selectively kill tumor cells by enzymatic reactions without harming normal cells, as well as exploring two or more enzyme‐engineered nanoreactors for cascading catalytic reactions, remain great challenges in the field of targeted and specific cancer diagnostics and therapy. The latest research advances in nanozyme‐catalyzed cascade processes for cancer diagnosis and therapy are described in this article. Here, various sensing strategies are summarized, for tumor‐specific diagnostics. Targeting mechanisms for tumor treatment using cascade nanozymes are classified and analyzed, "elements" and "dimensions" of cascade nanozymes, types, designs of structure, and assembly modes of highly active and specific cascade nanozymes, as well as a variety of new strategies of tumor targeting based on the cascade reaction of nanozymes. Finally, the integrated application of the cascade nanozymes systems in tumor‐targeted and specific diagnostic therapy is summarized, which will lay the foundation for the design of more rational, efficient, and specific tumor diagnostic and therapeutic modalities in the future. [ABSTRACT FROM AUTHOR]

Based on the peroxidase activity of Cu-hemin metal–organic framework (Cu-hemin MOF) nanozyme, a colorimetric enzyme-linked immunosensor was developed for the detection of furazolidone (FZD). Cu-hemin MOF is a bimetallic nanozyme that exhibited a stronger catalytic effect compared with single-metal organic framework nanoenzymes. Cu-hemin-MOF catalyzes hydrogen peroxide (H2O2) to produce hydroxyl radicals (•OH), which oxidizes the chromogenic substrate 3,3′,5,5′-tetramethylbenzidine (TMB) to blue oxidized TMB (oxTMB). The absorbance change is at 650 nm. The content of AOZ in animal food can be quickly and accurately determined by changes in absorbance. The linear range of the colorimetric biosensor for detecting FZD was 0.01 ~ 62.52 ng/mL, and the limit of detection was as low as 0.01 ng/mL. The recovery of spikes samples was in the range 94.2-108.0 % and reproducibility was less than 4.8%. In addition, the cross-reaction rate was less than 0.1% when detecting other metabolites except AOZ, indicating that the sensor has good applicability and specificity. This study not only provides a better understanding of the relationship between the dispersion of nanoenzymes and enzyme-like activity but also offers a general method for detecting antibiotics using the nanoenzyme colorimetric method. [ABSTRACT FROM AUTHOR]

Developing powerful immunoassays for sensitive and real-time detection of targets has always been a challenging task. Due to their advantages of direct readout, controllable sensing, and low background interference, photothermal immunoassays have become a type of new technology that can be used for various applications such as disease diagnosis, environmental monitoring, and food safety. By modification with antibodies, photothermal materials can induce temperature changes by converting light energy into heat, thereby reporting specific target recognition events. This article reviews the design and application of photothermal immunoassays based on different photothermal materials, including noble metal nanomaterials, carbon-based nanomaterials, two-dimensional nanomaterials, metal oxide and sulfide nanomaterials, Prussian blue nanoparticles, small organic molecules, polymers, etc. It pays special attention to the role of photothermal materials and the working principle of various immunoassays. Additionally, the challenges and prospects for future development of photothermal immunoassays are briefly discussed. [ABSTRACT FROM AUTHOR]

Nanozymes are a new kind of material which has been applied since the beginning of this century, and its birth has promoted the development of chemistry, materials science, and biology. Nanozymes can be used as a substitute for natural enzyme and has a wide range of applications; therefore, it has attracted extensive attention from all sectors of the community, and the number of studies has constantly increasing. In this paper, we introduced the outstanding achievements in the field of nanozymes in recent years from the main function, the construction of nanozyme-based biosensors, and the treatment of ischemic stroke, and we also illustrated the internal mechanism and the catalytic principle. In the end, the obstacles and challenges in the future development of nanozymes were proposed. [ABSTRACT FROM AUTHOR]

Abstract As novel multifunctional materials that merge enzyme-like capabilities with the distinctive traits of nanomaterials, nanozymes have made significant strides in interdisciplinary research areas spanning materials science, bioscience, and beyond. This article, for the first time, employed bibliometric methods to conduct an in-depth statistical analysis of the global nanozymes research and demonstrate research progress, hotspots and trends. Drawing on data from the Web of Science Core Collection database, we comprehensively retrieved the publications from 2004 to 2024. The burgeoning interest in nanozymes research across various nations indicated a growing and widespread trend. This article further systematically elaborated the enzyme-like activities, matrix, multifunctional properties, catalytic mechanisms and various applications of nanozymes, and the field encounters challenges. Despite notable progress, and requires deeper exploration guide the future research directions. This field harbors broad potential for future developments, promising to impact various aspects of technology and society. Graphical abstract

Abstract As the pathophysiological basis of type 2 diabetes mellitus (T2DM), insulin resistance (IR) is closely related to oxidative stress (OS) and inflammation, while nanozymes have a good therapeutic effect on inflammation and OS by scavenging reactive oxygen species (ROS). Hence, AuCePt porous hollow cascade nanozymes (AuCePt PHNs) are designed by integrating the dominant enzymatic activities of three metallic materials, which exhibit superior superoxide dismutase/catalase-like activities, and high drug loading capacity. In vitro experiments proved that AuCePt PHNs can ultra-efficiently scavenge endogenous and exogenous ROS. Moreover, AuCePt PHNs modified with lactobionic acid (LA) and loaded with disulfiram (DSF), named as AuCePt PHNs-LA@DSF, can significantly improve glucose uptake and glycogen synthesis in IR hepatocytes by regulating the insulin signaling pathways (IRS-1/AKT) and gluconeogenesis signaling pathways (FOXO-1/PEPCK). Intravenous administration of AuCePt PHNs-LA@DSF not only showed high liver targeting efficiency, but also reduced body weight and blood glucose and improved IR and lipid accumulation in high-fat diet-induced obese mice and diabetic ob/ob mice. This research elucidates the intrinsic activity of AuCePt PHNs for cascade scavenging of ROS, and reveals the potential effect of AuCePt PHNs-LA@DSF in T2DM treatment. Graphical abstract

Abstract Background In diabetic wounds, hyperglycemia-induced cytotoxicity and impaired immune microenvironment plasticity directly hinder the wound healing process. Regulation of the hyperglycemic microenvironment and remodeling of the immune microenvironment are crucial. Results Here, we developed a nanozymatic functionalized regenerative microenvironmental regulator (AHAMA/CS-GOx@Zn-POM) for the effective repair of diabetic wounds. This novel construct integrated an aldehyde and methacrylic anhydride-modified hyaluronic acid hydrogel (AHAMA) and chitosan nanoparticles (CS NPs) encapsulating zinc-based polymetallic oxonate nanozyme (Zn-POM) and glucose oxidase (GOx), facilitating a sustained release of release of both enzymes. The GOx catalyzed glucose to gluconic acid and (H₂O₂), thereby alleviating the effects of the hyperglycemic microenvironment on wound healing. Zn-POM exhibited catalase and superoxide dismutase activities to scavenge reactive oxygen species and H₂O₂, a by-product of glucose degradation. Additionally, Zn-POM induced M1 macrophage reprogramming to the M2 phenotype by inhibiting the MAPK/IL-17 signaling diminishing pro-inflammatory cytokines, and upregulating the expression of anti-inflammatory mediators, thus remodeling the immune microenvironment and enhancing angiogenesis and collagen regeneration within wounds. In a rat diabetic wound model, the application of AHAMA/CS-GOx@Zn-POM enhanced neovascularization and collagen deposition, accelerating the wound healing process. Conclusions Therefore, the regenerative microenvironment regulator AHAMA/CS-GOx@Zn-POM can achieve the effective conversion of a pathological microenvironment to regenerative microenvironment through integrated control of the hyperglycemic-immune microenvironment, offering a novel strategy for the treatment of diabetic wounds.

Abstract Plants such as herbs, vegetables, fruits, and cereals are closely related to human life. Developing effective testing methods to ensure their safety and quantify their active components are of significant importance. Recently, nanomaterials with enzyme-like activity (known as nanozymes) have been widely developed in various assays, including colorimetric, fluorescence, chemiluminescence, and electrochemical analysis. This review presents the latest advances in analyzing phytochemicals and hazardous substances in plant samples based on nanozymes, including some active ingredients, organophosphorus pesticides, heavy metal ions, and mycotoxins. Additionally, the current shortcomings and challenges of the actual sample analysis were discussed.

[Display omitted] • A double variable-valence nanoscale metal–organic layer nanozyme He@Ce-BTB (Fe@Ce nMOL) was designed and constructed. • The ultra-thin structure of nanozyme He@Ce-BTB provided more catalytic sites. • Double variable-valence He@Ce-BTB could promote the efficiency of ROS generation and induce ferroptosis. • He@Ce-BTB exhibited potential application prospects in the field of anticancer treatment. Nanozymes have made great achievements in the research of tumor therapy. However, due to the complex tumor microenvironment, the catalytic activity and biosafety of nanozymes are limited. High catalytic efficiency is a relentless pursuit for the preparation of high-performance nanozymes. Dimensional reduction from 3D nanoscale metal–organic frameworks (nMOFs) to 2D nanoscale metal–organic layers (nMOLs) increases the encounters frequency of nanozymes and substrate, which facilitates the diffusion of reactive oxygen species (ROS) from nMOLs, thus significantly improving the effectiveness of chemodynamic therapy. In this study, He@Ce-BTC nMOF and He@Ce-BTB nMOL based on Ce 6 SBUs were synthesized by solvothermal reaction. Compared with the 3D nMOFs, the 2D nanozymes He@Ce-BTB nMOL possessed enhanced ROS catalytic efficiency, were able to be activated by the tumor acidic microenvironment with the polymerase mimetic activities (CAT, POD, GSH-OXD) that enhances the lipid peroxidation process and accelerates the process of ferroptosis thereby killing tumor cells. In addition, He@Ce-BTB does not affect normal tissue cells, thus avoiding diffusion-induced side effects. He@Ce-BTB has shown excellent therapeutic effects in vitro and in vivo , which indicates its potential for clinical application, and is expected to become a new generation of drugs for the treatment of tumors. [ABSTRACT FROM AUTHOR]

[Display omitted] • A multi-functional integrated nanoplatform for multimodal synergistic tumor therapy. • A tumor microenvironment-responsive PtAu/MnO 2 cascade nanoreactor with multi-enzymatic activities. • It can significantly inhibit tumor growth via ferroptosis/starvation therapy/apoptosis pathways. The utilization or improvement of tumor microenvironment (TME) has become a breakthrough in emerging oncology therapies. To address the limited therapeutic efficacy of single modality, a multi-functional integrated nanoplatform based on a TME-responsive PtAu/MnO 2 cascade nanoreactor with multi-enzymatic activities was developed for multimodal synergistic tumor therapy. Benefiting from the slightly acidic environment and high-level glutathione (GSH) in TME, PtAu/MnO 2 cascade nanoreactor consumed GSH, followed by the reductive generation of manganese ion (Mn2+) and the release of PtAu nanoparticles (NPs). Then, the multimodal synergistic tumor therapy was activated as follows. First, GSH depletion inhibited the activity of glutathione peroxidase 4 and led to the accumulation of lipid peroxidation, thereby inducing tumor cell ferroptosis. Second, PtAu NPs exhibited catalase-like, glucose oxidase-like and nicotinamide adenine dinucleotide (NADH) oxidase-like activities, which generated oxygen for the cascade reaction to alleviate hypoxia and further depleted glucose, NADH and adenosine triphosphate, leading to the inhibition of tumor cell proliferation via starvation therapy. Third, the production of reactive oxygen species by the oxidase- and peroxidase-like activities of PtAu NPs and the Fenton-like reaction of Mn2+ simultaneously induced tumor cell apoptosis via chemodynamic therapy. Briefly, the in vitro and in vivo results confirmed that the multi-functional integrated nanoplatform based on a PtAu/MnO 2 cascade nanoreactor with five nanozyme activities demonstrated outstanding biocompatibility and greater inhibition of tumor growth via synergistic ferroptosis/starvation therapy/apoptosis. [ABSTRACT FROM AUTHOR]

Manganese oxide/nitrogen-doped carbon composite nanoparticles (MnO-N/C NPs) for magnetic resonance imaging (MRI)-guided photothermal-enhanced catalytic therapy and photothermal therapy for hepatocellular carcinoma using near-infrared light to modulate multiple enzyme activities. [Display omitted] Nano-enzymatic catalytic therapy has been widely explored as a promising tumor therapeutic method with specific responsiveness to the tumor microenvironment (TME). However, the inherent lower and simplex catalytic efficiency impairs their anti-tumor efficacy. Therefore, developing novel nanozymes with relatively high and multiple catalytic characteristics, simultaneously enhancing the enzyme-like activity of nanozymes using the proper method, photothermal promoted catalytic property, is a reliable way. In this paper, we report a manganese oxide/nitrogen-doped carbon composite nanoparticles (MnO-N/C NPs) with multi-enzyme mimetic activity and photothermal conversional effect. The peroxidase (POD)-like/oxidase (OXD)-like/catalase (CAT)-like activity of MnO-N/C nanozymes was accelerated upon exposure to an 808 nm NIR laser. In vitro and in vivo results proved that the MnO-N/C NPs shown excellent magnetic resonance imaging (MRI) guided synergistic photothermal-enhanced catalytic treatment and photothermal therapy of liver cancer. The photothermal enhanced multi-enzyme activity maximizes the efficacy of catalytic and photothermal therapy while reducing harm to healthy cells, thereby offering valuable insights for the development of next-generation photothermal nanozymes to enhance tumor therapy. [ABSTRACT FROM AUTHOR]

Norfloxacin is widely used owing to its strong bactericidal effect on Gram-negative bacteria. However, the residual norfloxacin in the environment can be biomagnified via food chain and may damage the human liver and delay the bone development of minors. Present work described a reliable and sensitive smartphone colorimetric sensing system based on cobalt-doped Fe 3 O 4 magnetic nanoparticles (Co-Fe 3 O 4 MNPs) for the visual detection of norfloxacin. Compared with Fe 3 O 4 , Co-Fe 3 O 4 MNPs earned more remarkably peroxidase-like activity and TMB (colorless) was rapidly oxidized to oxTMB (blue) with the presence of H 2 O 2. Interestingly, the addition of low concentration of norfloxacin can accelerate the color reaction process of TMB, and blue deepening of the solution can be observed with the naked eye. However, after adding high concentration of norfloxacin, the activity of nanozyme was inhibited, resulting in the gradual fading of the solution. Based on this principle, a colorimetric sensor integrated with smartphone RGB mode was established. The visual sensor exhibited good linearity for norfloxacin monitoring in the range of 0.13-2.51 µmol/L and 17.5-100 µmol/L. The limit of visual detection was 0.08 µmol/L. In the actual water sample analysis, the spiked recoveries of norfloxacin were over the range of 95.7%-104.7 %. These results demonstrated that the visual sensor was a convenient and fast method for the efficient and accurate detection of norfloxacin in water, which may have broad application prospect. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • CoNiCoNC can catalyze the self-supply of H 2 O 2 from glucose and lactate, alleviating low H 2 O 2 levels in the tumor TME. • CoNiCoNC has the ability to catalyze the production of O2 from H 2 O 2 to alleviate hypoxia in tumor TME. • CoNiCoNC has GSH oxidase-like activity and causes cellular ferroptosis. • CoNiCoNC can catalyze the production of large amounts of ROS by H 2 O 2 in the tumor microenvironment and damage tumor cells. The effectiveness of chemokinetic therapy nanozymes is severely constrained because of the low H 2 O 2 levels in the tumor microenvironment. Unlike other self-produced H 2 O 2 nanozymes, the N -CNTs-encapsulated CoNi alloy (CoNiCoNC) with glucose oxidase and lactate oxidase activities has two ways to produce H 2 O 2. It can facilitate the transformation of glucose and lactic acid into H 2 O 2 simultaneously. First, the H 2 O 2 generation pathway is favorable for aggravating energy metabolism. Second, some produced H 2 O 2 can be decomposed by CoNiCoNC to H 2 O and O 2 with the 4e − pathway to alleviate the TME hypoxia. Third, H 2 O 2 can be catalyzed to form OH to enhance reactive oxygen species (ROS) content. Through proteomic analysis, nanozymes substantially impact the metabolic pathways of cancer cells because of their aggravating energy metabolism. The high levels of ROS can cause mitochondrial lipid peroxidation and cellular ferroptosis. Consequently, the two-way H 2 O 2 -selective nanoenzymatic platform realizes the synergistic effect of starvation therapy and chemokinetics. [ABSTRACT FROM AUTHOR]

Abstract Nanozymes, a category of nanomaterials with enzyme-like activity, have garnered growing interest in various biomedical contexts. Notably, nanozymes that are capable of regulating reactive oxygen species levels by emulating antioxidant or prooxidant enzymes within cells hold significant therapeutic potential for a range of disorders. Herein, we overview the catalytic mechanisms of four exemplary nanozymes within the orthopedic domain. Subsequently, we emphasize recent groundbreaking advancements in nanozyme applications in orthopaedics, encompassing osteoarthritis, osteoporosis, intervertebral disc degeneration, bone defects, spinal cord injury, gout, rheumatoid arthritis, osteosarcoma and bone infection. Furthermore, we discuss the emerging area’s future prospects and several noteworthy challenges in biomedical application. This review not only fosters the ongoing development of nanozyme research but also fosters the emergence of more potent nanozymes for the treatment of orthopaedical diseases in the future.

Abstract Doxorubicin (DOX) is the most common treatment for breast cancer, but its effectiveness is limited by drug resistance and dose variability. Evidence suggests that nanozymes can significantly improve drug penetration and effectiveness in breast cancer treatment, owing to their stable and targeted catalytic properties. However, their varied responses and concentration-dependent toxicities present challenges. After developing pH-sensitive Fe3O4/MnO2@DOX hybrid nanozymes (FMDHN) and evaluating their physicochemical and functional properties, their efficacy was investigated on MCF-7 cells using both two-dimensional and spheroid models. Our findings reveal that FMDHNs, sized 150–270 nm, inhibit MCF-7 cell growth through drug release triggered by acidity and photothermal therapy (PTT). The catalytic efficiency of FMHN in generating O2 and ·OH further enhances cancer cell suppression. Doubling the effective concentrations of FMHN and DOX by transitioning from two-dimensional to spheroid cell structures could adversely affect normal cells, while a synergistic approach combining the DOX and FMHN effectively inhibits MCF-7 cell growth at non-toxic dose. Combining FMDHN with PTT enhances this inhibition, lowering the effective dose to 1.08 μg/mL and effectively managing toxicity. The cytotoxicity mechanism in MCF-7 spheroids shows that PTT with FMDHN significantly elevates pro-inflammatory cytokines, including TNF-α, CASP9, CASP7 and CASP3. Optimizing the concentration of pH-sensitive nanozymes based on their synergistic effects can minimize side effects and maximize their breast cancer treatment potential. Graphical Abstract

Abstract Background Breast cancer, with its high morbidity and mortality rates, is a significant global health burden. Traditional treatments—surgery, chemotherapy, and radiotherapy—are widely used but come with drawbacks such as recurrence, metastasis, and significant side effects, including damage to healthy tissues. To address these limitations, new therapeutic strategies are being developed. Peroxidases (POD) can catalyze excess H2O2 in the tumor microenvironment to generate reactive oxygen species (ROS), which induce cancer cell apoptosis by disrupting redox homeostasis and modulating apoptosis-related proteins. However, natural enzymes face challenges like poor stability, high cost, and sensitivity to environmental conditions, limiting their application in breast cancer treatment. Nanozymes, nanomaterials with enzyme-like activity, offer a promising alternative by overcoming these limitations. Methods In this study, we successfully prepared Au@Pd nanozymes with peroxidase activity by depositing metallic Pd on Au nanoparticles (Au NPs) synthesized using a trisodium citrate reduction method and ascorbic acid reduction. The in vitro validation was conducted through a series of experiments, including ROS detection, flow cytometry, CCK-8 assay, DNA damage assessment, live/dead cell staining, Western blot (WB), and qPCR. Tumor treatment was performed via tail vein injection of the drug, followed by HE staining of the treated tissues and biochemical analysis of the blood. Results Au@Pd nanozymes can effectively accumulate at the tumor site through the EPR effect and exert peroxidase-like activity, catalyzing the excess H2O2 in the tumor microenvironment to produce ROS. This triggers apoptosis pathways and DNA damage, leading to the downregulation of the anti-apoptotic protein Bcl-2, upregulation of the pro-apoptotic protein Bax, and induction of apoptosis-related genes, demonstrating strong anti-tumor effects. Conclusions This study developed an efficient nanozyme-mediated catalytic therapy strategy targeting the tumor microenvironment for the treatment of breast cancer cells.

Abstract Cerium oxide (CeO2) nanospheres have limited enzymatic activity that hinders further application in catalytic therapy, but they have an “oxidation switch” to enhance their catalytic activity by increasing oxygen vacancies. In this study, according to the defect-engineering strategy, we developed PtCuOX/CeO2-X nanozymes as highly efficient SOD/CAT mimics by introducing bimetallic copper (Cu) and platinum (Pt) into CeO2 nanospheres to enhance the oxygen vacancies, in an attempt to combine near-infrared (NIR) irradiation to regulate microenvironment for osteoarthritis (OA) therapy. As expected, the Cu and Pt increased the Ce3+/Ce4+ ratio of CeO2 to significantly enhance the oxygen vacancies, and simultaneously CeO2 (111) facilitated the uniform dispersion of Cu and Pt. The strong metal-carrier interaction synergy endowed the PtCuOX/CeO2-X nanozymes with highly efficient SOD/CAT-like activity by the decreased formation energy of oxygen vacancy, promoted electron transfer, the increased adsorption energy of intermediates, and the decreased reaction activation energy. Besides, the nanozymes have excellent photothermal conversion efficiency (55.41%). Further, the PtCuOX/CeO2-X antioxidant system effectively scavenged intracellular ROS and RNS, protected mitochondrial function, and inhibited the inflammatory factors, thus reducing chondrocyte apoptosis. In vivo, experiments demonstrated the biosafety of PtCuOX/CeO2-X and its potent effect on OA suppression. In particular, NIR radiation further enhanced the effects. Mechanistically, PtCuOX/CeO2-X nanozymes reduced ras-related C3 botulinum toxin substrate 1 (Rac-1) and p-p65 protein expression, as well as ROS levels to remodel the inflammatory microenvironment by inhibiting the ROS/Rac-1/nuclear factor kappa-B (NF-κB) signaling pathway. This study introduces new clinical concepts and perspectives that can be applied to inflammatory diseases. Graphical Abstract

Doxorubicin (DOX) is the most common treatment for breast cancer, but its effectiveness is limited by drug resistance and dose variability. Evidence suggests that nanozymes can significantly improve drug penetration and effectiveness in breast cancer treatment, owing to their stable and targeted catalytic properties. However, their varied responses and concentration-dependent toxicities present challenges. After developing pH-sensitive Fe3O4/MnO2@DOX hybrid nanozymes (FMDHN) and evaluating their physicochemical and functional properties, their efficacy was investigated on MCF-7 cells using both two-dimensional and spheroid models. Our findings reveal that FMDHNs, sized 150–270 nm, inhibit MCF-7 cell growth through drug release triggered by acidity and photothermal therapy (PTT). The catalytic efficiency of FMHN in generating O2 and ·OH further enhances cancer cell suppression. Doubling the effective concentrations of FMHN and DOX by transitioning from two-dimensional to spheroid cell structures could adversely affect normal cells, while a synergistic approach combining the DOX and FMHN effectively inhibits MCF-7 cell growth at non-toxic dose. Combining FMDHN with PTT enhances this inhibition, lowering the effective dose to 1.08 μg/mL and effectively managing toxicity. The cytotoxicity mechanism in MCF-7 spheroids shows that PTT with FMDHN significantly elevates pro-inflammatory cytokines, including TNF-α, CASP9, CASP7 and CASP3. Optimizing the concentration of pH-sensitive nanozymes based on their synergistic effects can minimize side effects and maximize their breast cancer treatment potential. [ABSTRACT FROM AUTHOR]

Regulating appropriate valence states of metal active centers, such as Ce3+/Ce4+ and Mn3+/Mn2+, as well as surface vacancy defects, is crucial for enhancing the catalytic activity of cerium‐based and manganese‐based nanozymes. Drawing inspiration from the efficient substance exchange in rhizobia‐colonized root cells of legumes, we developed a symbiosis nanozyme system with rhizobia‐like CeOx nanoclusters robustly anchored onto root‐like Mn3O4 nanosupports (CeOx/Mn3O4). The process of “substance exchange” between Ce and Mn atoms—reminiscent of electron transfer—not only fine‐tunes the metal active sites to achieve optimal Ce3+/Ce4+ and Mn3+/Mn2+ ratios but also enhances the vacancy ratio through interface defect engineering. Additionally, the confinement anchoring of CeOx on Mn3O4 ensures efficient electron transfer in catalytic reactions. The final CeOx/Mn3O4 nanozyme demonstrates potent catalase‐like (CAT‐like) and superoxide dismutase‐like (SOD‐like) activities, excelling in both chemical settings and cellular environments with high reactive oxygen species (ROS) levels. This research not only unveils a novel material adept at effectively eliminating ROS but also presents an innovative approach for amplifying the efficacy of nanozymes. [ABSTRACT FROM AUTHOR]

The prevalence of neurological dieases, including neurodegenerative, neurotraumatic disorders, and neuroinflammatory conditions, has been rising due to global population and aging demographics. A key factor in the pathogenesis of these disorders is the hyperaccumulation of reactive oxygen and nitrogen species (RONS). Nanozymes have emerged as promising candidates for neurotherapeutic applications owing to their exceptional catalytic activity and stability. Of particular note is their ability to cross the blood‐brain barrier and counteract the production of reactive oxygen species via their enzyme‐mimicking characteristics. In this review, the latest advancements and theoretical knowledge in this research domain are summarized. Using the inherent functionalities of the Web of Science and bibliometric methodologies, annual publication trends are identified and extensively explored the most researched topics and neurological disorders in this field. The antioxidant reduction chemistry of the nanozymes is discussed, highlighting their ability to mimic natural oxidoreductase activity and inhibit RONS production at the source. Moreover, this review delves into the current limitations and future prospects of these mechanisms in addressing neurological disorders. The significant benefits and recent developments in the use of RONS‐regulating nanozymes for the treatment of neurological diseases are emphasized, offering insights into their therapeutic applications and broader implications for neurology. [ABSTRACT FROM AUTHOR]

Carbonic anhydrase (CA) is an important enzyme which breaks the C−O bond and catalyzes the hydration of CO2 and developing artificial enzyme to mimic the function of CA is important for the related applications. Zeolitic imidazolate frameworks (ZIFs) with typical tetrahedral Zn−N coordination units which were similar to the catalytically active site of natural CA have been reported to displayed CA‐like activities. However, the activity of crystalline ZIFs remains unsatisfactory. Herein, amorphous zeolitic imidazolate framework (aZIF) was fabricated through a facile self‐assembly process and exhibited 2.2‐fold higher CA‐like hydrolytic activity than the corresponding crystalline ZIF‐8.This phenomenon can be ascribed to the unsaturated Zn−N coordination structure and mesopores inside aZIF. This work affords a new avenue for the rational design of nanozymes. [ABSTRACT FROM AUTHOR]

Nanozymes, a category of nanomaterials with enzyme-like activity, have garnered growing interest in various biomedical contexts. Notably, nanozymes that are capable of regulating reactive oxygen species levels by emulating antioxidant or prooxidant enzymes within cells hold significant therapeutic potential for a range of disorders. Herein, we overview the catalytic mechanisms of four exemplary nanozymes within the orthopedic domain. Subsequently, we emphasize recent groundbreaking advancements in nanozyme applications in orthopaedics, encompassing osteoarthritis, osteoporosis, intervertebral disc degeneration, bone defects, spinal cord injury, gout, rheumatoid arthritis, osteosarcoma and bone infection. Furthermore, we discuss the emerging area's future prospects and several noteworthy challenges in biomedical application. This review not only fosters the ongoing development of nanozyme research but also fosters the emergence of more potent nanozymes for the treatment of orthopaedical diseases in the future. [ABSTRACT FROM AUTHOR]

A promising and sought-after class of nanozymes for various applications is Pt-containing nanozymes, primarily Au@Pt, due to their easy preparation and remarkable catalytic properties. This study aimed to explore the freeze–thaw method for functionalizing Pt-containing nanozymes with oligonucleotides featuring a polyadenine anchor. Spherical gold nanoparticles ([Au]NPs) were synthesized and subsequently used as seeds to produce urchin-like Au@Pt nanoparticles ([Au@Pt]NPs) with an average diameter of 29.8 nm. The nanoparticles were conjugated with a series of non-thiolated DNA oligonucleotides, each consisting of three parts: a 5′-polyadenine anchor (An, with n = 3, 5, 7, 10; triple-branched A3, or triple-branched A5), a random sequence of 23 nucleotides, and a linear polyT block consisting of seven deoxythymine residues. The resulting conjugates were characterized using transmission electron microscopy, spectroscopy, dynamic light scattering, and emission detection of the fluorescent label at the 3′-end of each oligonucleotide. The stability of the conjugates was found to depend on the type of oligonucleotide, with decreased stability in the row of [Au@Pt]NP conjugates with A7 > A5 > 3A3 > 3A5 > A10 > A3 anchors. These [Au@Pt]NP–oligonucleotide conjugates were further evaluated using lateral flow test strips to assess fluorescein-specific binding and peroxidase-like catalytic activity. Conjugates with A3, A5, A7, and 3A3 anchors showed the highest levels of signals of bound labels on test strips, exceeding conjugates in sensitivity by up to nine times. These findings hold significant potential for broad application in bioanalytical systems. [ABSTRACT FROM AUTHOR]