A bioinspired sulfur-Fe-heme nanozyme with selective peroxidase-like activity for enhanced tumor chemotherapy.

Iron-based nanozymes, recognized for their biocompatibility and peroxidase-like activities, hold promise as catalysts in tumor therapy. However, their concurrent catalase-like activity undermines therapeutic efficacy by converting hydrogen peroxide in tumor tissues into oxygen, thus diminishing hydroxyl radical production. Addressing this challenge, this study introduces the hemin-cysteine-Fe (HCFe) nanozyme, which exhibits exclusive peroxidase-like activity.

A Novel "Three-in-One" Copper-Based Metal-Organic Framework Nanozyme Eradicates Colorectal Cancer and Overcomes Chemoresistance for Tumor Therapy.

Despite considerable advancements in the treatment of colorectal cancer (CRC), the overall survival rate for patients with advanced CRC remains below 50%, primarily due to challenges posed by drug resistance and metastasis. Here, a novel "Three-in-One" Cu-based metal-organic framework nanozyme with peroxidase-like (POD-like) activity has been successfully developed, aiming to promote CRC cell death by dual targeting of oxidative stress and copper ion homeostasis, which could promote CRC cell death via apoptosis and cuproptosis, and facilitate hypoxia-inducible factor 1α (HIF-1α) degradation, leading to the reversal of chemoresistance in tumor therapy. These nanozymes, composed of copper and 2-propylimidazole (Cu-PrIm), feature a distorted Cu-N4 catalytic active center that mimics natural enzyme structures consisting of copper and histidine residues, endowing them with enzyme-like activities.

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

The tumor microenvironment (TME) exhibits characteristics such as hypoxia, weak acidity, and enrichment of glutathione and hydrogen peroxide (HO), which greatly limits the effectiveness of tumor magnetic resonance imaging (MRI) and photodynamic therapy (PDT). Carbon dots (CDs) nanozymes are excellent candidate materials with both diagnostic and therapeutic potential. However, CDs nanozymes with both ultra-high relaxation rate and good therapeutic effect are still to be developed.

Axial Chlorination Engineering of Single-Atom Nanozyme: Fe-NCl Catalytic Sites for Efficient Peroxidase-Mimicking.

Developing axial coordination engineering of single-atom nanozymes (SAzymes), directly regulating the axial coordination environment of the catalytic site, and optimizing the axial adsorption are meaningful and challenging for boosting the enzyme-like activities. Herein, the axial chlorination engineering of SAzyme with the Fe-NCl catalytic site (Fe-NCl/CNCl) was first proposed, exhibiting superior peroxidase-like activity compared to the traditional Fe-N/CN SAzyme with Fe-N site. The maximal reaction velocity (4.

Mimicomes: Mimicking Multienzyme System by Artificial Design.

Enzymes are widely distributed in organelles of cells, which are capable of carrying out specific catalytic reactions. In general, several enzymes collaborate to facilitate complex reactions and engage in vital biochemical processes within cells, which are also called cascade systems. The cascade systems are highly efficient, and their dysfunction is associated with a multitude of endogenous diseases.

Atom-pair engineering of single-atom nanozyme for boosting peroxidase-like activity.

Constructing atom-pair engineering and improving the activity of metal single-atom nanozyme (SAzyme) is significant but challenging. Herein, we design the atom-pair engineering of Zn-SA/CNCl SAzyme by simultaneously constructing Zn-N sites as catalytic sites and Zn-NCl sites as catalytic regulator. The Zn-NCl catalytic regulators effectively boost the peroxidase-like activities of Zn-N catalytic sites, resulting in a 346-fold, 1496-fold, and 133-fold increase in the maximal reaction velocity, the catalytic constant and the catalytic efficiency, compared to Zn-SA/CN SAzyme without the Zn-NCl catalytic regulator.

Stable peptide-assembled nanozyme mimicking dual antifungal actions.

Natural antimicrobial peptides (AMPs) and enzymes (AMEs) are promising non-antibiotic candidates against antimicrobial resistance but suffer from low efficiency and poor stability. Here, we develop peptide nanozymes which mimic the mode of action of AMPs and AMEs through de novo design and peptide assembly. Through modelling a minimal building block of IHIHICI is proposed by combining critical amino acids in AMPs and AMEs and hydrophobic isoleucine to conduct assembly.

Nanomaterial-Based Strategies for Attenuating T-Cell-Mediated Immunodepression in Stroke Patients: Advancing Research Perspectives.

This review article discusses the potential of nanomaterials in targeted therapy and immunomodulation for stroke-induced immunosuppression. Although nanomaterials have been extensively studied in various biomedical applications, their specific use in studying and addressing immunosuppression after stroke remains limited. Stroke-induced neuroinflammation is characterized by T-cell-mediated immunodepression, which leads to increased morbidity and mortality.

Nanozybiotics: Advancing Antimicrobial Strategies Through Biomimetic Mechanisms.

Infectious diseases caused by bacterial, viral, and fungal pathogens present significant global health challenges. The rapid emergence of antimicrobial resistance exacerbates this issue, leading to a scenario where effective antibiotics are increasingly scarce. Traditional antibiotic development strategies are proving inadequate against the swift evolution of microbial resistance.

Deciphering the Catalytic Mechanism of Peroxidase-like Activity of Iron Sulfide Nanozymes.

Iron sulfide nanomaterials represented by FeS and FeS nanozymes have attracted increasing attention due to their biocompatibility and peroxidase-like (POD-like) catalytic activity in disease diagnosis and treatments. However, the mechanism responsible for their POD-like activities remains unclear. Herein, taking the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) by HO on FeS(100) and FeS(001) surfaces, the catalytic mechanism was investigated in detail using density functional theory (DFT) calculations and experimental characterizations.

Iron-Confined CRISPR/Cas9-Ribonucleoprotein Delivery System for Redox-Responsive Gene Editing.

Clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9) is a promising gene editing tool to treat diseases at the genetic level. Nonetheless, the challenge of the safe and efficient delivery of CRISPR/Cas9 to host cells constrains its clinical applicability. In the current study, a facile, redox-responsive CRISPR/Cas9-Ribonucleoprotein (RNP) delivery system by combining iron-coordinated aggregation with liposomes (Fe-RNP@L) is reported.

Effective Treatment of Infection Using Supramolecular Antimicrobial Peptide Hydrogels.

can cause various gastric conditions including stomach cancer in an acidic environment. Although early infections can be treated by antibiotics, prolonged antibiotic administrations may lead to the development of antimicrobial resistance, compromising the effectiveness of the treatments. Antimicrobial peptides (AMPs) have been reported to possess unique advantages against antimicrobial-resistant bacteria due to their rapid physical membrane disruptions and anti-inflammation/immunoregulation properties.

Low-Temperature Adaptive Single-Atom Iron Nanozymes against Viruses in the Cold Chain.

Outbreaks of viral infectious diseases, such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A virus (IAV), pose a great threat to human health. Viral spread is accelerated worldwide by the development of cold chain logistics; Therefore, an effective antiviral approach is required. In this study, it is aimed to develop a distinct antiviral strategy using nanozymes with low-temperature adaptability, suitable for cold chain logistics.

Exploring the Specificity of Nanozymes.

Nanozymes, nanomaterials exhibiting enzyme-like activities, have emerged as a prominent interdisciplinary field over the past decade. To date, over 1200 different nanomaterials have been identified as nanozymes, covering four catalytic categories: oxidoreductases, hydrolases, isomerases, and lyases. Catalytic activity and specificity are two pivotal benchmarks for evaluating enzymatic performance.

An Erythrocyte-Templated Iron Single-Atom Nanozyme for Wound Healing.

Iron single-atom nanozymes represent a promising artificial enzyme with superior activity owing to uniform active sites that can precisely mimic active center of nature enzymes. However, current synthetic strategies are hard to guarantee each active site at single-atom state. In this work, an erythrocyte-templated strategy by utilizing intrinsic hemin active center of hemoglobin as sing-atom source for nanozyme formation is developed.

Diatomic iron nanozyme with lipoxidase-like activity for efficient inactivation of enveloped virus.

Enveloped viruses encased within a lipid bilayer membrane are highly contagious and can cause many infectious diseases like influenza and COVID-19, thus calling for effective prevention and inactivation strategies. Here, we develop a diatomic iron nanozyme with lipoxidase-like (LOX-like) activity for the inactivation of enveloped virus. The diatomic iron sites can destruct the viral envelope via lipid peroxidation, thus displaying non-specific virucidal property.

Histidine modulates amyloid-like assembly of peptide nanomaterials and confers enzyme-like activity.

Amyloid-like assembly is not only associated with pathological events, but also leads to the development of novel nanomaterials with unique properties. Herein, using Fmoc diphenylalanine peptide (Fmoc-F-F) as a minimalistic model, we found that histidine can modulate the assembly behavior of Fmoc-F-F and induce enzyme-like catalysis. Specifically, the presence of histidine rearranges the β structure of Fmoc-F-F to assemble nanofilaments, resulting in the formation of active site to mimic peroxidase-like activity that catalyzes ROS generation.

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

The contrast agents and tumor treatments currently used in clinical practice are far from satisfactory, due to the specificity of the tumor microenvironment (TME). Identification of diagnostic and therapeutic reagents with strong contrast and therapeutic effect remains a great challenge. Herein, a novel carbon dot nanozyme (Mn-CD) is synthesized for the first time using toluidine blue (TB) and manganese as raw materials.

Mackinawite nanozymes as reactive oxygen species scavengers for acute kidney injury alleviation.

Background: Iron sulfide nanomaterials have been successfully employed as therapeutic agents for bacterial infection therapy and catalytic-ferroptosis synergistic tumor therapy due to their unique structures, physiochemical properties, and biocompatibility. However, biomedical research and understanding of the biological functions of iron sulfides are insufficient, and how iron sulfide nanomaterials affect reactive oxygen species (ROS) in diseases remains unknown. Acute kidney injury (AKI) is associated with high levels of ROS, and therefore nanomedicine-mediated antioxidant therapy has emerged as a novel strategy for its alleviation.

Rescuing Nucleus Pulposus Cells From Senescence via Dual-Functional Greigite Nanozyme to Alleviate Intervertebral Disc Degeneration.

High levels of reactive oxygen species (ROS) lead to progressive deterioration of mitochondrial function, resulting in tissue degeneration. In this study, ROS accumulation induced nucleus pulposus cells (NPCs) senescence is observed in degenerative human and rat intervertebral disc, suggesting senescence as a new therapeutic target to reverse intervertebral disc degeneration (IVDD). By targeting this, dual-functional greigite nanozyme is successfully constructed, which shows the ability to release abundant polysulfides and presents strong superoxide dismutase and catalase activities, both of which function to scavenge ROS and maintain the tissue at physical redox level.

Bidirectionally Regulating Viral and Cellular Ferroptosis with Metastable Iron Sulfide Against Influenza Virus.

Influenza virus with numerous subtypes and frequent variation limits the development of high-efficacy and broad-spectrum antiviral strategy. Here, a novel multi-antiviral metastable iron sulfides (mFeS) against various influenza A/B subtype viruses is developed. This work finds that mFeS induces high levels of lipid peroxidation and •OH free radicals in the conservative viral envelope, which depends on Fe .