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1.
The deficient catalytic activity of nanozymes and insufficient endogenous H2O2 in the tumor microenvironment (TME) are major obstacles for nanozyme-mediated catalytic tumor therapy. Since electron transfer is the basic essence of catalysis-mediated redox reactions, we explored the contributing factors of enzymatic activity based on positive and negative charges, which are experimentally and theoretically demonstrated to enhance the peroxidase (POD)-like activity of a MoS2 nanozyme. Hence, an acidic tumor microenvironment-responsive and ultrasound-mediated cascade nanocatalyst (BTO/MoS2@CA) is presented that is made from few-layer MoS2 nanosheets grown on the surface of piezoelectric tetragonal barium titanate (T-BTO) and modified with pH-responsive cinnamaldehyde (CA). The integration of pH-responsive CA-mediated H2O2 self-supply, ultrasound-mediated charge-enhanced enzymatic activity, and glutathione (GSH) depletion enables out-of-balance redox homeostasis, leading to effective tumor ferroptosis with minimal side effects.  相似文献   

2.
To address the poor cycling stability and low rate capability of MoS2 as electrode materials for lithium-ion batteries (LIBs), herein, the CoS2/MoS2/PDDA-rGO/PMo12 nanocomposites are constructed via a simple hydrothermal process, combining the advantages of all three, namely, CoS2/MoS2 heterojunction and polyoxometalates (POMs) provide abundant catalytically active sites and increase the multi-electron transfer ability, and the positively charged poly(diallyldimethylammonium chloride) modified reduced graphene oxide (PDDA-rGO) improve electronic conductivity and effectively prevent the aggregation of MoS2, meanwhile stabilize the negatively charged [PMo12O40]3−. After the electrochemical testing, the resulting CoS2/MoS2/PDDA-rGO/PMo12 nanocomposite achieved 1055 mA h g−1 initial specific capacities and stabilized at 740 mA h g−1 after 150 cycles at 100 mA g−1 current density. And the specific capacities of MoS2, MoS2/PDDA-rGO, CoS2/MoS2, and CoS2/MoS2/PDDA-rGO were 201, 421, 518, and 589 at 100 mA g−1 after 150 cycles, respectively. The fact of the greatly improving capacity of MoS2-based nanocomposites suggests its potential for high performance electrode materials of LIBs. Moreover, the lithium storage mechanism of CoS2/MoS2/PDDA-rGO/PMo12 has been discussed on the basis of cyclic voltammetry with different scan rates.  相似文献   

3.
Single-atom nanozymes (SAzymes) are promising in next-generation nanozymes, nevertheless, how to rationally modulate the microenvironment of SAzymes with controllable multi-enzyme properties is still challenging. Herein, we systematically investigate the relationship between atomic configuration and multi-enzymatic performances. The constructed MnSA−N3-coordinated SAzymes (MnSA−N3−C) exhibits much more remarkable oxidase-, peroxidase-, and glutathione oxidase-like activities than that of MnSA−N4−C. Based on experimental and theoretical results, these multi-enzyme-like behaviors are highly dependent on the coordination number of single atomic Mn sites by local charge polarization. As a consequence, a series of colorimetric biosensing platforms based on MnSA−N3−C SAzymes is successfully built for specific recognition of biological molecules. These findings provide atomic-level insight into the microenvironment of nanozymes, promoting rational design of other demanding biocatalysts.  相似文献   

4.
Nanomaterials with enzyme-like activities, termed as nanozymes, have found wide applications in various fields. It has been a long-term aim to rationally design and synthesize highly active nanozymes and thus to further improve their application performance. Guided by the nanoconfinement effect, we confine cytochrome c (Cyt c) within a mesoporous metal–organic framework (MOF), PCN-222 nanoparticle (NP), forming a protein/MOF hybrid nanozyme, termed as Cyt c@PCN-222 NP. The confined Cyt c exhibits around 3–4-fold higher peroxidase-like activity than free Cyt c. Due to the increase in the activity of Cyt c, the Cyt c@PCN-222 NPs exhibit a quite low limit of detection (≈0.13 μM) towards H2O2. Sonication-induced H2O2 formation in water by using a lab-quipped ultrasonic cleaner can be sensitively probed, which suggests that H2O2-sensitive materials should be carefully handled during the utilization of ultrasonic equipment. We speculate that this nanoconfinement strategy can broaden our synthetic methodology for the rational design of nanozymes.  相似文献   

5.
Developing efficient nanozymes to mimic natural enzymes for scavenging reactive radicals remains a significant challenge owing to the insufficient activity of conventional nanozymes. Herein, we report a novel Ru single-atom nanozyme (SAE), featuring atomically dispersed Ru atoms on a biocompatible MgAl-layered double hydroxide (Ru1/LDH). The prepared Ru1/LDH SAE shows high intrinsic peroxidase (POD)-like catalytic activity, which outperforms the Ru nanoclusters (NCs) nanozyme by a factor of 20 and surpasses most SAEs. The density functional theory calculations reveal that the high intrinsic POD-like activity of Ru1/LDH can be attributed to a heterolytic path of H2O2 dissociation on the single Ru sites, which requires lower free energy (0.43 eV) compared to the homolytic path dissociation on Ru NC (0.63 eV). In addition, the Ru1/LDH SAE shows excellent multiple free radicals scavenging ability, including superoxide anion radical (O2), hydroxyl radical (⋅OH), nitric oxide radical (NO⋅) and 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH⋅). Given the advantages of Ru1/LDH with high enzymatic activities, biosafety, and ease to scale up, it paves the way for exploring SAEs in the practical biological immunity system.  相似文献   

6.
Nanozymes have attracted extensive interest owing to their high stability, low cost and easy preparation, especially in the field of cancer therapy. However, the relatively low catalytic activity of nanozymes in the tumor microenvironment (TME) has limited their applications. Herein, we report a novel nanozyme (PtFe@Fe3O4) with dual enzyme‐like activities for highly efficient tumor catalytic therapy. PtFe@Fe3O4 shows the intrinsic photothermal effect as well as photo‐enhanced peroxidase‐like and catalase‐like activities in the acidic TME, thereby effectively killing tumor cells and overcoming the tumor hypoxia. Importantly, a possible photo‐enhanced synergistic catalytic mechanism of PtFe@Fe3O4 was first disclosed. We believe that this work will advance the development of nanozymes in tumor catalytic therapy.  相似文献   

7.
Nanomaterials with enzyme‐like activities (nanozymes) attracts significant interest due to their therapeutic potential for the treatment of various diseases. Herein, we report that a Mn3O4 nanozyme functionally mimics three major antioxidant enzymes, that is, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and the multienzyme activity is size as well as morphology‐dependent. The redox modulatory effect of Mn3O4 plays a crucial role in protecting the cells from MPP+ induced cytotoxicity in a Parkinson disease (PD)‐like cellular model, indicating that manganese‐based nanomaterials having multi‐enzyme activity can robustly rescue the cells from oxidative damage and thereby possess therapeutic potential to prevent ROS‐mediated neurological disorders.  相似文献   

8.
《中国化学快报》2023,34(1):107585
Inhibition of foam cell formation is considered a promising treatment method for atherosclerosis, the leading cause of cardiovascular diseases worldwide. However, currently available therapeutic strategies have shown unsatisfactory clinical outcomes. Thus, herein, we design aloperine (ALO)-loaded and hyaluronic acid (HA)-modified palladium (Pd) octahedral nanozymes (Pd@HA/ALO) that can synergistically scavenge reactive oxygen species (ROS) and downregulate cyclooxygenase-2 (COX-2) expression to induce macrophage polarization, thus inhibiting foam cell formation to attenuate atherosclerosis. Due to the targeted effect of HA on stabilin-2 and CD44, which are overexpressed in atherosclerotic plaques, Pd@HA/ALO can actively accumulate in atherosclerotic plaques. Subsequently, the antioxidative effects of Pd octahedral nanozymes are mediated by their intrinsic superoxide dismutase- and catalase-like activities capable of effective scavenging of ROS. In addition, anti-inflammatory effects are mediated by controlled, on-demand near-infrared-triggered ALO release leading to inhibition of COX-2 expression. Importantly, the combined therapy can promote the polarization of macrophages to the M2 subtype by upregulating Arg-1 and CD206 expression and downregulating expression of TNF-α, IL-1β and IL-6, thereby inhibiting atherosclerosis-related foam cell formation. In conclusion, the presented in vitro and in vivo data demonstrate that Pd@HA/ALO enhanced macrophage polarization to reduce plaque formation, identifying an attractive treatment strategy for cardiovascular disease.  相似文献   

9.
Recently, nanozymes have attracted extensive attention because of their advantages of combining nanomaterials with enzymes. Herein, hexagonal boron nitride (h‐BN) and nitride‐doped molybdenum disulfide (N?MoS2) nano‐composites (h‐BN/N?MoS2) were synthesized by facile and cost‐effective liquid exfoliation with a solvothermal method in nontoxic ethanol solution. The results show that h‐BN, as a co‐catalyst, can not only dope into the lattice of MoS2 but also form a heterogeneous structure with MoS2NSs. It expanded the layer spacing and specific surface area of MoS2NSs, which was beneficial to the contact between the catalyst and the substrate, and resulted in a synergistic enhancement of the catalytic activity of hydrogen peroxide (H2O2) with MoS2. A colorimetric determination platform of h‐BN/N?MoS2‐TMB‐H2O2 was constructed. It exhibited a wide linear range of 1–1000 μM with a low limit of detection (LOD) of 0.4 μM under optimal conditions, high sensitivity and stability, as well as good reliability (99.4–110.0%) in practice, making the measurement system more widely applicable.1. Introduction  相似文献   

10.
《中国化学快报》2021,32(9):2715-2728
With high catalytic activity and stability, nanozymes have huge advantage in generating or eliminating the reactive oxygen species (ROS) due to their intrinsic enzyme-mimicking abilities, therefore attracting wide attention in ROS-related disease therapy. To better design nanozyme-based platforms for ROS-related biological application, we firstly illustrate the catalytic mechanism of different activities, and then introduce different strategies for using nanozymes to augment or reduce ROS level for the applications in cancer therapy, pathogen infection, neurodegeneration, etc. Finally, the challenges and future opportunities are proposed for the development and application of nanozymes.  相似文献   

11.
The accumulation and deposition of β-amyloid (Aβ) plaques in the brain is considered a potential pathogenic mechanism underlying Alzheimer's disease (AD). Chiral l/d -FexCuySe nanoparticles (NPs) were fabricated that interfer with the self-assembly of Aβ42 monomers and trigger the Aβ42 fibrils in dense structures to become looser monomers under 808 nm near-infrared (NIR) illumination. d -FexCuySe NPs have a much higher affinity for Aβ42 fibrils than l -FexCuySe NPs and chiral Cu2−xSe NPs. The chiral FexCuySe NPs also generate more reactive oxygen species (ROS) than chiral Cu2−xSe NPs under NIR-light irradiation. In living MN9D cells, d -NPs attenuate the adhesion of Aβ42 to membranes and neuron loss after NIR treatment within 10 min without the photothermal effect. In-vivo experiments showed that d -FexCuySe NPs provide an efficient protection against neuronal damage induced by the deposition of Aβ42 and alleviate symptoms in a mouse model of AD, leading to the recovery of cognitive competence.  相似文献   

12.
Tumor-associated macrophages (TAMs) play a critical role in the immunosuppressive solid tumor microenvironment (TME), yet in situ engineering of TAMs for enhanced tumor immunotherapy remains a significant challenge in translational immuno-oncology. Here, we report an innovative nanodrug-delivering-drug (STNSP@ELE) strategy that leverages two-dimensional (2D) stanene-based nanosheets (STNSP) and β-Elemene (ELE), a small-molecule anticancer drug, to overcome TAM-mediated immunosuppression and improve chemo-immunotherapy. Our results demonstrate that both STNSP and ELE are capable of polarizing the tumor-supportive M2-like TAMs into a tumor-suppressive M1-like phenotype, which acts with the ELE chemotherapeutic to boost antitumor responses. In vivo mouse studies demonstrate that STNSP@ELE treatment can reprogram the immunosuppressive TME by significantly increasing the intratumoral ratio of M1/M2-like TAMs, enhancing the population of CD4+ and CD8+ T lymphocytes and mature dendritic cells, and elevating the expression of immunostimulatory cytokines in B16F10 melanomas, thereby promoting a robust antitumor response. Our study not only demonstrates that the STNSP@ELE chemo-immunotherapeutic nanoplatform has immune-modulatory capabilities that can overcome TAM-mediated immunosuppression in solid tumors, but also highlights the promise of this nanodrug-delivering-drug strategy in developing other nano-immunotherapeutics and treating various types of immunosuppressive tumors.  相似文献   

13.
对映选择性催化是生物体内普遍存在的反应,与生命的产生代谢有着非常紧密的联系。设计研发具有高对映选择性催化效果的纳米酶在各类生物医药相关领域都至关重要。目前,关于纳米酶的研究大都集中在提高其催化活性,而涉及纳米酶对映选择性的研究相对较少。已有对映选择性酶催化报道表明,手性纳米酶主要通过手性分子修饰纳米颗粒来构建。考虑到天然酶的选择性不仅仅取决于氨基酸等手性分子的手性,而且与蛋白质空间排列和折叠所产生的超分子手性微环境密切相关,因此构建具有超分子手性微环境的纳米酶也成为设计具有优异对映选择性纳米酶的有效途径。此外,为了进一步提高手性纳米酶的对映选择性,深入理解手性纳米酶选择性因子的影响因素也成为一个重要研究方向。基于此,本文构建了一种由不含任何手性分子的M-聚苯胺(M-PANI)扭曲纳米带和三种不同尺寸(3、10和16 nm)的金纳米颗粒(AuNPs)组成的超分子纳米复合材料。扫描电子显微镜、透射电子显微镜、紫外-可见吸收光谱和X射线光电子能谱结果证实了M-PANI-Au超分子纳米复合材料的成功制备。同时,圆二色光谱显示M-PANI-Au超分子复合材料具有清晰的手性信号,表明它们在手性纳米催化方面具有潜在应用。以手性R-/S-3, 4-二羟基苯丙氨酸(R-/S-DOPA)对映体的催化氧化为模型反应,该类纳米酶对R-DOPA的催化选择性均高于对S-DOPA。进一步研究表明,得益于超分子手性聚苯胺载体和3 nm AuNPs之间的强手性传递作用,3 nm Au NPs(2.59)负载的M-PANI比10 nm Au NPs(1.46)和16 nm NPs(1.58)负载的M-PANI具有更高的选择因子。这一发现阐明了手性转移是调控对映选择性催化的关键影响因素,为负载型超分子手性纳米酶的构建和设计提供了方向和指导。  相似文献   

14.
Biofunctionalized TiO2 nanoparticles with a size range of 18.42±1.3 nm were synthesized in a single-step approach employing Grape seed extract (GSE) proanthocyanin (PAC) polyphenols. The effect of PACs rich GSE corona was examined with respect to 1) the stability and dispersity of as-synthesized GSE-TiO2-NPs, 2) their antiproliferative and antibiofilm efficacy, and 3) their propensity for internalization and reactive oxygen species (ROS) generation in urinary tract infections (UTIs) causing Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus saprophyticus strains. State-of-the-art techniques were used to validate GSE-TiO2-NPs formation. Comparative Fourier transformed infrared (FTIR) spectral analysis demonstrated that PACs linked functional -OH groups likely play a central role in Ti4+ reduction and nucleation to GSE-TiO2-NPs, while forming a thin, soft corona around nascent NPs to attribute significantly enhanced stability and dispersity. Transmission electron microscopic (TEM) and inductively coupled plasma mass-spectroscopy (ICP-MS) analyses confirmed there was significantly (p<0.05) enhanced intracellular uptake of GSE-TiO2-NPs in both Gram-negative and -positive test uropathogens as compared to bare TiO2-NPs. Correspondingly, compared to bare NPs, GSE-TiO2-NPs induced intracellular ROS formation that corresponded well with dose-dependent inhibitory patterns of cell proliferation and biofilm formation in both the tested strains. Overall, this study demonstrates that -OH rich PACs of GSE corona on biogenic TiO2-NPs maximized the functional stability, dispersity and propensity of penetration into planktonic cells and biofilm matrices. Such unique merits warrant the use of GSE-TiO2-NPs as a novel, functionally stable and efficient antibacterial nano-formulation to combat the menace of UTIs in clinical settings.  相似文献   

15.
The artificial enzyme-mimicking system using nanomaterials has attracted significant research interest in chemical and biological sensing for industrial and environmental applications. Mn3O4 nanostructure serves as an effective catalyst in oxidation and reduction reactions that mimic natural peroxidase enzymes. In this study, we synthesized Mn3O4–Au spindle nanocomposites (Mn3O4–Au SNCs) stabilized by L-cysteine using a simple hydrothermal reduction. The enzyme-mimicking peroxidase activity of these Mn3O4–Au SNCs with hydrogen peroxide (H2O2) was investigated in the presence of a chromogenic substrate, 3,3′,5,5′-tetramethylbenzidine that catalyzed reduction of H2O2 in water and milk giving rise to a blue color inferring the nanozyme activity of Mn3O4–Au SNCs. The exceptional enzyme-like catalytic activity of Mn3O4–Au SNC probes later proved to be excellent surface-enhanced Raman scattering (SERS) sensor nanoprobes for sensitive H2O2 detection over a wide concentration range from 0.005 to 10 μM. The developed Mn3O4–Au SERS sensor exhibited a lower detection limit (LoD) of 2 nM in water and 0.6 μM in spiked milk indicating sensitivity for H2O2 detection with excellent selectivity, reproducibility, and long-term stability. The developed Mn3O4–Au nanoprobes demonstrated unique combination of properties with visual and SERS methods for sensitively detecting H2O2 in food, overcoming limitations of existing H2O2 sensors. The developed SERS method using nanozymes potentially be extended to detecting a variety of other redox chemicals or explosives in industries, environments, and biomedical fields.  相似文献   

16.
Hydrogen spillover effect was studied in the presence of CoS x /Al2O3 and bulk MoS2, prepared by thermal decomposition of ammonium tetrathiomolibdate (NH4)2MoS4 dibensothiopene hydrodesulfurization, quinoline hydrodenitrogenation, and Guaiacol dehydrodeoxygenation in micro-flow set at 275–350°C and pressure 3.0 MPa.  相似文献   

17.
Nanozymes have emerged as a new generation of antibiotics with exciting broad‐spectrum antimicrobial properties and negligible biotoxicities. However, their antibacterial efficacies are unsatisfactory due to their inability to trap bacteria and their low catalytic activity. Herein, we report nanozymes with rough surfaces and defect‐rich active edges. The rough surface increases bacterial adhesion and the defect‐rich edges exhibit higher intrinsic peroxidase‐like activity compared to pristine nanozymes due to their lower adsorption energies of H2O2 and desorption energy of OH*, as well as the larger exothermic process for the whole reaction. This was demonstrated using drug‐resistant Gram‐negative Escherichia coli and Gram‐positive Staphylococcus aureus in vitro and in vivo. This strategy can be used to engineer nanozymes with enhanced antibacterial function and will pave a new way for the development of alternative antibiotics.  相似文献   

18.
Intrinsic enzyme-mimic activity of inorganic nanoparticles has been widely used for nanozymatic anticancer and antibacterial treatment. However, the relatively low peroxidase-mimic activity (PMA) and catalse-mimic activity (CMA) of nanozymes in tumor microenvironment has hampered their potential application in the cancer therapy. Therefore, in this study, we aimed to fabricate platinum (Pt) nanozymes dispersed on the surface of iron oxide (Fe3O4) nanosphere that, in addition to boosting the PMA and CMA, resulted in the formation of a pH-sensitive nano-platform for drug delivery in breast cancer therapy. After development of Fe3O4 nanospheres containing Pt nanozymes and loading 5-fluorouracil (abbreviated as: Fe3O4/Pt-FLU@PEG nanospheres), the physicochemical properties of the nanospheres were examined by electron microscopy, dynamic light scattering, zeta potential, X-ray diffraction, thermogravimetric, BET surface, and PMA/CMA analyses. Then, the cytotoxicity of the Fe3O4/Pt-FLU@PEG nanospheres against 4T1 cells was investigated by the cell counting kit-8 assay and flow cytometry. Also, the anticancer effect of fabricated nanoplatform was assessed in mouse bearing 4T1 cancer tumors, in vivo. The results showed that the Fe3O4/Pt-FLU@PEG nanospheres provide a platform for optimal FLU loading, continuous pH-sensitive drug release, and potential PMA and CMA to increase the level of ROS and O2, respectively. Cytotoxicity outputs showed that the Fe3O4/Pt-FLU@PEG nanospheres mitigate the proliferation of 4T1 cancer cells mediated by apoptosis and intracellular generation of reactive oxygen species (ROS). Furthermore, in vivo assays indicated a significant reduction in tumor size and overcoming tumor hypoxia. Overall, we believe that the developed nanospheres with dual enzyme-mimic activity and pH-sensitive drug delivery can be used for ROS/chemotherapy double-modality antitumor therapy.  相似文献   

19.
Hypertension, as a leading risk factor for cardiovascular diseases, is associated with oxidative stress and impairment of endogenous antioxidant mechanisms, but there is still a tremendous knowledge gap between hypertension treatment and nanomedicines. Herein, we report a specific nanozyme based on ultrathin two-dimensional (2D) niobium carbide (Nb2C) MXene, termed Nb2C MXenzyme, to fight against hypertension by achieving highly efficient reactive oxygen species elimination and inflammatory factors inhibition. The biocompatible Nb2C MXenzyme displays multiple enzyme-mimicking activities, involving superoxide dismutase, catalase, glutathione peroxidase, and peroxidase, inducing cytoprotective effects by resisting oxidative stress, thereby alleviating inflammatory response and reducing blood pressure, which is systematically demonstrated in a stress-induced hypertension rat model. This strategy not only opens new opportunities for nanozymes to treat hypertension but also expands the potential biomedical applications of 2D MXene nanosystems.  相似文献   

20.
A powerful individual living cell encapsulation strategy for long‐term cytoprotection and manipulation is reported. It uses manganese dioxide (MnO2) nanozymes as intelligent shells. As expected, yeast cells can be directly coated with continuous MnO2 shells via bio‐friendly Mn‐based mineralization. Significantly, the durable nanozyme shells not only can enhance the cellular tolerance against severe physical stressors including dehydration and lytic enzyme, but also enable the survival of cells upon contact with high levels of toxic chemicals for prolonged periods. More importantly, these encased cells after shell removal via a facile biomolecule stimulus can fully resume growth and functions. This strategy is applicable to a broad range of living cells  相似文献   

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