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[Display omitted] The lack of selective release ability in the tumor microenvironment and the limited efficacy of monotherapy are important factors that limit the current use of carbon monoxide (CO) donors for tumor therapy. Herein, inspired by endogenous biochemical reactions in vivo , one kind of CO-releasing nanomotor was designed for the multimodal synergistic treatment of tumor. Specifically, glucose oxidase (GOx) and 5-aminolevulinic acid (5-ALA) were co-modified onto metal–organic framework material (MIL-101) to obtain MIL-GOx-ALA nanomotors (M-G-A NMs), which exhibit excellent biocompatibility and degradation ability in tumor microenvironment. Subsequently, the released 5-ALA generates CO in the tumor microenvironment through an endogenous reaction and further acts on mitochondria to release large amounts of reactive oxygen species (ROS), which directly kill tumor cells. Furthermore, the produced ROS and the degradation products of M-G-A NMs can also provide the reaction substrate for the Fenton reaction, thereby enhancing chemodynamic therapy (CDT) and inducing apoptosis of tumor cells. Both in vitro and in vivo experimental data confirm the successful occurrence of the above process, and the combination of CO gas therapy/enhanced CDT can effectively inhibit tumor growth. This CDT-enhancing agent designed based on endogenous biochemical reactions has good prospects for tumor treatment application. [ABSTRACT FROM AUTHOR]

Nanomedicine has reshaped the landscape of cancer treatment. However, its efficacy is still hampered by innate tumor defense systems that rely on adenosine triphosphate (ATP) for fuel, including damage repair, apoptosis resistance, and immune evasion. Inspired by the naturally enzymatic reaction of glucose oxidase (GOx) with glucose, here a novel "two birds with one stone" technique for amplifying enzyme‐mediated tumor apoptosis and enzyme‐promoted metabolic clearance is proposed and achieved using GOx‐functionalized rhenium nanoclusters‐doped polypyrrole (Re@ReP‐G). Re@ReP‐G reduces ATP production while increasing H2O2 concentrations in the tumor microenvironment through GOx‐induced enzymatic oxidation, which in turn results in the downregulation of defense (HSP70 and HSP90) and anti‐apoptotic Bcl‐2 proteins, the upregulation of pro‐apoptotic Bax, and the release of cytochrome c. These processes are further facilitated by laser‐induced hyperthermia effect, ultimately leading to severe tumor apoptosis. As an enzymatic byproduct, H2O2 catalyzes the conversion of rhenium nanoclusters in Re@ReP‐G nanostructures into rhenate from the outside in, which accelerates their metabolic clearance in vivo. This Re@ReP‐G‐based "two birds with one stone" therapeutic strategy provides an effective tool for amplifying tumor apoptosis and safe metabolic mechanisms. [ABSTRACT FROM AUTHOR]

In this study we examine effect of the solvent ratio on TiO 2 physical and photoelectrochemical properties utilizing economical hydrothermal process. Sample properties were examined using XRD, SEM, Raman, UV–vis, PL, photocurrent, Mott–Schottky, and EIS measurements. XRD patterns revealed that TiO 2 samples represent a polycrystalline nature with a Tetragonal structure. Peaks at 609, 144, and 443 cm−1 were observed in Raman spectra indicating the production of the TiO 2 rutile phase. SEM images showed that TiO 2 nanorods formed evenly with square top facets and a tetragonal form. UV–vis results displayed an optical absorption edge between 386 and 405 nm which is associated with the band gap of TiO 2 NRs films. The generated TiO 2 NRs films exhibit n-type semiconductor behavior according to the photocurrent measurements. Mott-Schottky experiments indicated that the donor density and flat band potential varied with decreased acid ratio from 1.55 × 1018 to 3.33 × 1018 cm−3 and-0.47 to-0.72 V, respectively. As observed by EIS, the resistivity to charge transfer declined, reaching its lowest level at 5:11 ml, indicating improvement of electrochemical activity and structural properties with decreasing the HCl concentration. Additionally, the fabricated TiO2 NRs films was employed as biosensor for glucose where a fast amperometric response and good operating stability were detected. [ABSTRACT FROM AUTHOR]

Radiotherapy-induced immune activation holds great promise for optimizing cancer treatment efficacy. Here, we describe a clinically used radiosensitizer hafnium oxide (HfO2) that was core coated with a MnO2 shell followed by a glucose oxidase (GOx) doping nanoplatform (HfO2@MnO2@GOx, HMG) to trigger ferroptosis adjuvant effects by glutathione depletion and reactive oxygen species production. This ferroptosis cascade potentiation further sensitized radiotherapy by enhancing DNA damage in 4T1 breast cancer tumor cells. The combination of HMG nanoparticles and radiotherapy effectively activated the damaged DNA and Mn2+-mediated cGAS-STING immune pathway in vitro and in vivo. This process had significant inhibitory effects on cancer progression and initiating an anticancer systemic immune response to prevent distant tumor recurrence and achieve long-lasting tumor suppression of both primary and distant tumors. Furthermore, the as-prepared HMG nanoparticles "turned on" spectral computed tomography (CT)/magnetic resonance dual-modality imaging signals, and demonstrated favorable contrast enhancement capabilities activated by under the GSH tumor microenvironment. This result highlighted the potential of nanoparticles as a theranostic nanoplatform for achieving molecular imaging guided tumor radiotherapy sensitization induced by synergistic immunotherapy. [ABSTRACT FROM AUTHOR]

Background: The pre-analytical (PA) phase is the most vulnerable phase of the laboratory testing procedure, with critical procedures-collection, handling, sample transport, and time and temperature of sample storage. This study aimed to examine the stability of basic biochemical parameters depending on the samples' storage conditions and the number of freeze-thaw cycles (FTCs). In parallel, the presence of sample bacterial contamination during routine laboratory work was examined. Methods: Two plasma pools (ethylenediaminetetraacetic acid (EDTA), and sodium-fluoride/potassium oxalate plasma (NaF)) were stored at +4 °C/-20 °C. Total chole - sterol (TC), glucose, triglycerides (TG), urea, and albumin concentrations were measured using BioSystems reagents (cholesterol oxidase/peroxidase, glucose oxidase/per - oxidase, glycerol phosphate oxidase/peroxidase, urease/salicylate, and bromcresol green method, respectively) on Ilab 300+. Sample bacterial contamination was determined by 16S rRNA sequence analysis. The expe - riment encompassed a 5 day-period: Day 1-fresh sample, Day 2-1st FTC, Day 3-2nd FTC, Day 4-3rd FTC, Day 5-4th FTC. The appearance of bacteria in two consecutive samples was the experiment's endpoint. Results: During 4 FTCs, there were no changes in plasma urea concentrations. Glucose was stable in EDTA +4 °C and NaF -20 °C until the 3rd FTC (P=0.008, P=0.042, respectively). TG concentrations changed significantly in the EDTA -20 °C sample after 1st and 4th FTCs (P=0.022, P=0.010, respectively). In NaF samples, no bacterial contamination was observed during 4 FTCs. Conclusion: Urea and glucose concentrations were robust. Changes in lipid concentrations after FTCs follow complex patterns. Bacterial growth was not observed in NaF plasma samples. This can promote NaF use in analytical procedures in which bacterial contamination affects the quality of analysis. [ABSTRACT FROM AUTHOR]

Directed toward the limitations of natural enzymes in diabetes management, it is possible to design nano-enzymatic structures and modulate the activity as needed to obtain superior materials that are more suitable for the specific application environment. In this work, noble metal–semiconductor composite nanozymes [Te–Au nanowires (NWs)] were designed and their enzyme-like activities were systematically investigated for diabetes management. The results indicated that Te–Au NWs exhibited pH-switching multi-enzyme-like activities and adapted to a wider range of reaction conditions than natural enzymes. The kinetics of their enzyme-catalyzed reactions followed the Michaelis–Menten model, showing their substrate affinity similar to that of natural enzymes. Actually, the nanozymes showed reliable application stability, maintaining more than 80% of various enzyme activities under prolonged or extreme storage conditions. Furthermore, the nanozymes can be flexibly applied to various paths of glucose detection. For example, we constructed three different colorimetric detection methods to achieve the detection of glucose in saliva and blood. All three detection methods showed a wider linear range and lower limit of detection (LOD), among which the most optimal method was the combination of Te–Au NWs and glucose oxidase (GOx), with a linear range of 0.05–4 mM and a LOD of 2.11 μM. In summary, nanozymes with multiple enzyme-like activities have significant advantages and effectively address the limitations of natural enzymes in the application of diabetes management. [ABSTRACT FROM AUTHOR]

Here, we developed magnetically recoverable biocatalysts based on magnetite nanoparticles coated with an ultra-thin layer (about 0.9 nm) of chitosan (CS) ionically cross-linked by sodium tripolyphosphate (TPP). Excessive CS amounts were removed by multiple washings combined with magnetic separation. Glucose oxidase (GOx) was attached to the magnetic support via the interaction with N-hydroxysuccinimide (NHS) in the presence of carbodiimide (EDC) leading to a covalent amide bond. These steps result in the formation of the biocatalyst for D-glucose oxidation to D-gluconic acid to be used in the preparation of pharmaceuticals due to the benign character of the biocatalyst components. To choose the catalyst with the best catalytic performance, the amounts of CS, TPP, NHS, EDC, and GOx were varied. The optimal biocatalyst allowed for 100% relative catalytic activity. The immobilization of GOx and the magnetic character of the support prevents GOx and biocatalyst loss and allows for repeated use. [ABSTRACT FROM AUTHOR]

Considering the application prospects of a cascade catalytic system in biomedical analysis, it remains significant to develop a cascade catalytic system for one-step rapid colorimetric detection. Herein, PVP/NH2-MIL-101(Fe) possessing enhanced peroxidase (POD)-like activity was successfully synthesized by microwave-assisted and polyvinylpyrrolidone (PVP) modification strategies. Then, PVP/NH2-MIL-101(Fe) and glucose oxidase (GOx) were covalently coupled via the bifunctional cross-linker glutaraldehyde, the GOx@PVP/NH2-MIL-101(Fe) with dual enzymatic functional activities (POD-like and GOx activities) was subsequently synthesized. GOx@PVP/NH2-MIL-101(Fe) had strong affinities for the substrates glucose, 3,3',5,5'-tetramethylbenzidine, and hydrogen peroxide. Based on this specific nanozyme GOx@PVP/NH2-MIL-101(Fe), a one-step colorimetric assay for rapid glucose determination was built. This detection method not only took 20 min to analyze but also possessed a linear range of 10–250 µM with a detection limit of 1.05 µM. Furthermore, the cascade catalytic system was applied to determine glucose concentrations in human serum samples. Compared with commercial blood glucose meters, the proposed method was also accurate and effective, making it a candidate method for determining blood glucose. [ABSTRACT FROM AUTHOR]

Fish gelatin (FG)-based wound dressings exhibit superior water absorption capacity, thermal stability, and gelation properties, which enhance the performance of these dressings. In this study, our objective was to investigate the conditions underlying the enzymatic hydrolysis of FG and subsequent cross-linking to prepare high-performance gels. A two-step enzymatic method of protease-catalyzed hydrolysis followed by glutamine transglutaminase (TGase)-catalyzed cross-linking was used to prepare novel high-performance fish gelatin derivatives with more stable dispersion characteristics than those of natural gelatin derivatives. Compared with conventional TGase cross-linked derivatives, the novel derivatives were characterized by an average pore size of 150 μm and increased water solubility (423.06% to 915.55%), water retention (by 3.6-fold to 43.89%), thermal stability (from 313 °C to 323 °C), and water vapor transmission rate, which reached 486.72 g·m−2·24 h−1. In addition, loading glucose oxidase onto the fish gelatin derivatives increased their antibacterial efficacy to >99% against Escherichia coli and Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Microneedle array systems loaded with responsive nanoparticles have received increasing attention due to the advantages of good drug stability, targeting ability, controlled release of drugs, high bioavailability, painlessness, and good patient compliance. Compared with oral drug delivery, microneedle transdermal drug delivery eliminates the need to pass through the gastrointestinal tract and liver, reducing the metabolic consumption of drugs by first‐pass effect. While compared with intravenous drug delivery, microneedle transdermal drug delivery reduces patient discomfort and does not require professional administration. However, there are few review articles on microneedles loaded with responsive nanoparticles. Herein, the current researches on microneedles loaded with specific responsive nanoparticles such as glucose‐responsive, pH‐responsive, enzyme‐responsive, light‐responsive, magnetic‐responsive, ultrasound‐responsive, and multiresponsive, and the biomedical application of these microneedle array systems are summarized. In addition, the challenges and prospects of microneedle strategies loaded with responsive nanoparticles are briefly discussed, which will facilitate the development of such versatile drug‐delivery strategy. [ABSTRACT FROM AUTHOR]

Ethyl (S)-4-chloro-3-hydroxybutyrate ((S)-CHBE) is an important chiral intermediate in the synthesis of the cholesterol-lowering drug atorvastatin. Studying the use of SpyTag/SpyCatcher and SnoopTag/SnoopCatcher systems for the asymmetric reduction reaction and directed coupling coenzyme regeneration is practical for efficiently synthesizing (S)-CHBE. In this study, Spy and Snoop systems were used to construct a double-enzyme directed fixation system of carbonyl reductase (BsCR) and glucose dehydrogenase (BsGDH) for converting 4-chloroacetoacetate (COBE) to (S)-CHBE and achieving coenzyme regeneration. We discussed the enzymatic properties of the immobilized enzyme and the optimal catalytic conditions and reusability of the double-enzyme immobilization system. Compared to the free enzyme, the immobilized enzyme showed an improved optimal pH and temperature, maintaining higher relative activity across a wider range. The double-enzyme immobilization system was applied to catalyze the asymmetric reduction reaction of COBE, and the yield of (S)-CHBE reached 60.1% at 30 °C and pH 8.0. In addition, the double-enzyme immobilization system possessed better operational stability than the free enzyme, and maintained about 50% of the initial yield after six cycles. In summary, we show a simple and effective strategy for self-assembling SpyCatcher/SnoopCatcher and SpyTag/SnoopTag fusion proteins, which inspires building more cascade systems at the interface. It provides a new method for facilitating the rapid construction of in vitro immobilized multi-enzyme complexes from crude cell lysate. [ABSTRACT FROM AUTHOR]

[Display omitted] Starvation therapy has shown promise as a cancer treatment, but its efficacy is often limited when used alone. In this work, a multifunctional nanoscale cascade enzyme system, named CaCO 3 @MnO 2 -NH 2 @GOx@PVP (CMGP), was fabricated for enhanced starvation/chemodynamic combination cancer therapy. CMGP is composed of CaCO 3 nanoparticles wrapped in a MnO 2 shell, with glucose oxidase (GOx) adsorbed and modified with polyvinylpyrrolidone (PVP). MnO 2 decomposes H 2 O 2 in cancer cells into O 2 , which enhances the efficiency of GOx-mediated starvation therapy. CaCO 3 can be decomposed in the acidic cancer cell environment, causing Ca2+ overload in cancer cells and inhibiting mitochondrial metabolism. This synergizes with GOx to achieve more efficient starvation therapy. Additionally, the H 2 O 2 and gluconic acid produced during glucose consumption by GOx are utilized by MnO 2 with catalase-like activity to enhance O 2 production and Mn2+ release. This process accelerates glucose consumption, reactive oxygen species (ROS) generation, and CaCO 3 decomposition, promoting the Ca2+ release. CMGP can alleviate tumor hypoxia by cycling the enzymatic cascade reaction, which increases enzyme activity and combines with Ca2+ overload to achieve enhanced combined starvation/chemodynamic therapy. In vitro and in vivo studies demonstrate that CMGP has effective anticancer abilities and good biosafety. It represents a new strategy with great potential for combined cancer therapy. [ABSTRACT FROM AUTHOR]

[Display omitted] Reactive oxygen species (ROS)-centered chemodynamic therapy (CDT) holds significant potential for tumor-specific treatment. However, insufficient endogenous H 2 O 2 and extra glutathione within tumor microenvironment (TME) severely deteriorate the CDT's effectiveness. Herein, rich-Zn-Co 3 O 4 / N -doped porous carbon (Zn-Co 3 O 4 /NC) was fabricated by two-step pyrolysis, and applied to build high-efficiency nano-platform for synergistic cancer therapy upon combination with glucose oxidase (GOx), labeled Zn-Co 3 O 4 /NC-GOx for clarity. Specifically, the multiple enzyme-like activities of the Zn-Co 3 O 4 /NC were scrutinously investigated, including peroxidase-like activity to convert H 2 O 2 to O 2 ∙−, catalase-like activity to decompose H 2 O 2 into O 2 , and oxidase-like activity to transform O 2 to O 2 ∙−, which achieved the CDT through the catalytic cascade reaction. Simultaneously, GOx reacted with intracellular glucose to produce gluconic acid and H 2 O 2 , realizing starvation therapy. In the acidic TME, the Zn-Co 3 O 4 /NC-GOx rapidly caused intracellular Zn2+ pool overload and disrupted cellular homeostasis for ion-intervention therapy. Additionally, the Zn-Co 3 O 4 /NC exhibited glutathione peroxidase-like activity, which consumed glutathione in tumor cells and reduced the ROS consumption for ferroptosis. The tumor treatments offer some constructive insights into the nanozyme-mediated catalytic medicine, coupled by avoiding the TME limitations. [ABSTRACT FROM AUTHOR]

[Display omitted] The cancer therapeutic efficacy of the peroxidase (POD)-mimicking nanozyme-based monotherapy is significantly hindered due to insufficient intratumoral hydrogen peroxide (H 2 O 2) and glutathione (GSH) consumption effect on reactive oxygen species (ROS). In this study, we present the development of poly (o -phenylenediamine)@gold nanoparticles (AuNPs) (PoPD@Au) nanocomposites for multifunctional catalytic-photothermal therapy. These nanocomposites exhibit triple distinct nanozymatic activities, i.e. , POD-like activity that catalyzes H 2 O 2 to ROS, glucose oxidase (GOx)-like activity that supplements endogenous H 2 O 2 , and GSH depleting activity that decreases the ROS consumption efficiency. This open source and reduce expenditure strategy for ROS generation allows for the amplification of tumor oxidative stress, thereby enhancing anti-tumor efficiency. Additionally, the PoPD@Au nanocomposites demonstrate outstanding photothermal conversion efficiency, contributing to the synergistic effect between PoPD and AuNPs. Moreover, we reveal the improved photothermal performance of PoPD@Au triggered by the tumor microenvironment pH, which provides additional benefits for targeted catalytic-photothermal therapy. This "four-in-one" design of PoPD@Au enables efficient anti-tumor effects both in vitro and in vivo , making it a universal strategy for engineering catalytic-photothermal therapeutic nanoagents. [ABSTRACT FROM AUTHOR]

Background: Oxidative enzymes targeting lignocellulosic substrates are presently classified into various auxiliary activity (AA) families within the carbohydrate-active enzyme (CAZy) database. Among these, the fungal AA3 glucose–methanol–choline (GMC) oxidoreductases with varying auxiliary activities are attractive sustainable biocatalysts and important for biological function. CAZy AA3 enzymes are further subdivided into four subfamilies, with the large AA3_2 subfamily displaying diverse substrate specificities. However, limited numbers of enzymes in the AA3_2 subfamily are currently biochemically characterized, which limits the homology-based mining of new AA3_2 oxidoreductases. Importantly, novel enzyme activities may be discovered from the uncharacterized parts of this large subfamily. Results: In this study, phylogenetic analyses employing a sequence similarity network (SSN) and maximum likelihood trees were used to cluster AA3_2 sequences. A total of 27 AA3_2 proteins representing different clusters were selected for recombinant production. Among them, seven new AA3_2 oxidoreductases were successfully produced, purified, and characterized. These enzymes included two glucose dehydrogenases (TaGdhA and McGdhA), one glucose oxidase (ApGoxA), one aryl alcohol oxidase (PsAaoA), two aryl alcohol dehydrogenases (AsAadhA and AsAadhB), and one novel oligosaccharide (gentiobiose) dehydrogenase (KiOdhA). Notably, two dehydrogenases (TaGdhA and KiOdhA) were found with the ability to utilize phenoxy radicals as an electron acceptor. Interestingly, phenoxy radicals were found to compete with molecular oxygen in aerobic environments when serving as an electron acceptor for two oxidases (ApGoxA and PsAaoA), which sheds light on their versatility. Furthermore, the molecular determinants governing their diverse enzymatic functions were discussed based on the homology model generated by AlphaFold. Conclusions: The phylogenetic analyses and biochemical characterization of AA3_2s provide valuable guidance for future investigation of AA3_2 sequences and proteins. A clear correlation between enzymatic function and SSN clustering was observed. The discovery and biochemical characterization of these new AA3_2 oxidoreductases brings exciting prospects for biotechnological applications and broadens our understanding of their biological functions. [ABSTRACT FROM AUTHOR]

Wearable glucose biosensors enable noninvasive glucose monitoring, thereby enhancing blood glucose management. In this work, we present a wearable biosensor based on carbon black nanoparticles (CBNPs) for glucose detection in human sweat. The biosensor consists of CBNPs, Prussian blue (PB), glucose oxidase, chitosan, and Nafion. The fabricated biosensor has a linear range of 5 µM to 1250 µM, sensitivity of 14.64 µA mM−1 cm−2, and a low detection potential (−0.05 V, vs. Ag/AgCl). The detection limit for glucose was calculated as 4.83 µM. This reusable biosensor has good selectivity and stability and exhibits a good response to glucose in real sweat. These results demonstrate the potential of our CBNP-based biosensor for monitoring blood glucose in human sweat. [ABSTRACT FROM AUTHOR]

We describe the creation of a conductive microcavity based on the assembly of two pieces of carbon nanotube buckypaper for the entrapment of two enzymes, horseradish peroxidase (HRP) and glucose oxidase (GOx), as well as a redox mediator: 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid diammonium salt (ABTS). The hollow electrode, employing GOx, HRP, and the mediator, as an electrochemical enzyme cascade model, is utilized for glucose sensing at a potential of 50 mV vs. Ag/AgCl. This bienzyme electrode demonstrates the ability to oxidize glucose by GOx and subsequently convert H2O2 to water via the electrical wiring of HRP by ABTS. Different redox mediators (ABTS, potassium hexacyanoferrate (III), and hydroquinone) are tested for HRP wiring, with ABTS being the best candidate for the electroenzymatic reduction of H2O2. To demonstrate the possibility to optimize the enzyme cascade configuration, the enzyme ratio is studied with 1 mg HRP combined with variable amounts of GOx (1–4 mg) and 2 mg GOx combined with variable amounts of HRP (0.5–2 mg). The bienzyme electrode shows continuous operational stability for over a week and an excellent storage stability in phosphate buffer, with a decay of catalytic current by only 29% for 1 mM glucose after 100 days. [ABSTRACT FROM AUTHOR]

Background: Aspergillus niger ATCC 20611 is an industrially important fructooligosaccharides (FOS) producer since it produces the β-fructofuranosidase with superior transglycosylation activity, which is responsible for the conversion of sucrose to FOS accompanied by the by-product (glucose) generation. This study aims to consume glucose to enhance the content of FOS by heterologously expressing glucose oxidase and peroxidase in engineered A. niger. Results: Glucose oxidase was successfully expressed and co-localized with β-fructofuranosidase in mycelia. These mycelia were applied to synthesis of FOS, which possessed an increased purity of 60.63% from 52.07%. Furthermore, peroxidase was expressed in A. niger and reached 7.70 U/g, which could remove the potential inhibitor of glucose oxidase to facilitate the FOS synthesis. Finally, the glucose oxidase-expressing strain and the peroxidase-expressing strain were jointly used to synthesize FOS, which content achieved 71.00%. Conclusions: This strategy allows for obtaining high-content FOS by the multiple enzymes expressed in the industrial fungus, avoiding additional purification processes used in the production of oligosaccharides. This study not only facilitated the high-purity FOS synthesis, but also demonstrated the potential of A. niger ATCC 20611 as an enzyme-producing cell factory. [ABSTRACT FROM AUTHOR]

Aim. The purpose of our work was to test the effect of cafeteria diet and social isolation on physiological and biochemical indicators of mice. Materials and Methods. Female C57BL/6J mice aged 3 months were randomly sorted into four groups: co-housed control, co-housed cafeteria diet (CD), individually housed control (SI), and individually housed CD (CD SI). The CD comprised chocolate, nuts, crackers, and standard food (2:1 ratio) for 12 weeks. Body mass, food/water intake were monitored. Open field test assessed behavior using ToxTrack software. Blood glucose levels used LipidoCare lipidometer and glucose oxidase strip test. Myeloperoxidase activity measured spectrophotometrically in plasma. Paraoxonase activity evaluated using Tris-HCl, CaCl2, and supernatant mixture at 405 nm. GraphPad Prism 10 analyzed data via one-way ANOVA, Welch’s t-test with Benjamini-Hochberg correction. Results presented as mean ± SEM, with P ≤ 0.05 indicating significance between groups. Results and Discussion. Throughout the experiment, we monitored body mass of mice fed different diets and housed in groups or individually. As we can see in Fig. 1, mice that consumed the cafeteria diet in a group or individually gained body mass more rapidly than mice that fed a standard food. At the same time, mice kept individually gained body mass more intensively than their group counterparts (Fig. 1). During the experiment, we monitored also food consumption and water drinking. Fig. 2, A–B represent average consumption of food and water by mice in different groups. Grouped mice fed CD consumed more food than those fed a standard food (Fig. 2, A). Social isolation led to increase in food intake in both feeding groups, on the standard diet and CD. The cafeteria diet had no impact on group water intake in mice (Fig. 2, B). Socially isolated mice on a standard diet consumed more water than group-fed control mice. However, socially isolated mice on a cafeteria diet drank less water compared to those on a standard diet. Blood glucose levels were higher in all experimental groups compared to group-fed control mice on a standard diet (Fig. 3, C), indicating that both cafeteria diet and social isolation led to elevated blood glucose levels. This suggests increased food consumption in these mice. Grouped mice fed cafeteria diet spent more time in inner zone, than mice in other experimental groups (Fig. 3, A, B). Social isolation in the combination with the standard food did not affect the tested behavior parameters in mice compared with the control mice kept in the group (Fig. 3, A–D). Social isolation in the combination with the cafeteria diet increased locomotor activity of mice compared to other mouse groups, that indicates the development depression-like behavior in mice kept individually on cafeteria diet. Additionally, we quantified the protein content and assessed the activities of paraoxonase and myeloperoxidase to glean insights into oxidative stress levels, antioxidant capacity, and inflammatory status. As depicted in Fig. 4, A, discernible disparities were observed between the control group and all other experimental groups, suggestive of potential metabolic dysregulation. Moreover, in Fig. 4, B, a notable distinction was evident between the CD(SI) group and the remaining groups, indicative of heightened stress levels in the mice within this group. Conclusions. Social isolation combined with a standard diet in group-housed mice causes physiological changes similar to those induced by a cafeteria diet, including weight gain, increased food intake, and elevated blood glucose levels. However, only the cafeteria diet, not social isolation, lowers research activity. The combination of social isolation and cafeteria food exacerbates some changes, leading to greater weight gain, food consumption, and depressive behavior. Biochemical analyses revealed differences in oxidative stress, antioxidant capacity, and inflammatory status among experimental groups, with cafeteria diet and socially isolated mice showing distinct patterns indicative of metabolic dysregulation and heightened stress levels compared to control groups. [ABSTRACT FROM AUTHOR]

Diabetes has emerged as a global health crisis, with a substantial increase in prevalence and associated healthcare costs. The urgency for early diagnosis to prevent complications has fueled research into advanced biosensing technologies. Plasmonic sensors, leveraging localized surface plasmon resonance (LSPR), have gained prominence for their sensitivity. This study explores a metamaterial-based sensor platform comprising nanospheres fabricated through colloidal lithography. A comprehensive numerical and experimental analysis of the designed metamaterial-based sensor is presented, focusing on the spectral response at the resonance frequency of 535 nm. Finite-difference time-domain (FDTD) simulations reveal the field and charge distributions, enabling a systematic exploration of geometric parameters' impact on absorption resonance. The chosen optimum parameters are validated experimentally, demonstrating excellent agreement between numerical predictions and experimental outcomes. The spectral shifts occurring in the absorption spectrum of the sensor have demonstrated the molecular detection capability of very low concentrations of glucose oxidase, such as 0.001 ppm. Our approach, offering a cost-effective alternative to common fabrication methods, holds promise for the mass production of highly sensitive biosensors, providing a pathway for the development of advanced diagnostic tools for diabetes and other healthcare applications. [ABSTRACT FROM AUTHOR]

Although IgG-free immunosensors are in high demand owing to ethical concerns, the development of convenient immunosensors that alternatively integrate recombinantly produced antibody fragments, such as single-chain variable fragments (scFvs), remains challenging. The low affinity of antibody fragments, unlike IgG, caused by monovalent binding to targets often leads to decreased sensitivity. We improved the affinity owing to the bivalent effect by fabricating a bivalent antibody–enzyme complex (AEC) composed of two scFvs and a single glucose dehydrogenase, and developed a rapid and convenient scFv-employed electrochemical detection system for the C-reactive protein (CRP), which is a homopentameric protein biomarker of systemic inflammation. The development of a point-of-care testing (POCT) system is highly desirable; however, no scFv-based CRP-POCT immunosensors have been developed. As expected, the bivalent AEC showed higher affinity than the single scFv and contributed to the high sensitivity of CRP detection. The electrochemical CRP detection using scFv-immobilized magnetic beads and the bivalent AEC as capture and detection antibodies, respectively, was achieved in 20 min without washing steps in human serum and the linear range was 1–10 nM with the limit of detection of 2.9 nM, which has potential to meet the criteria required for POCT application in rapidity, convenience, and hand-held detection devices without employing IgGs. [ABSTRACT FROM AUTHOR]

As a potential tool for combating bacterial infections, chemodynamic therapy (CDT), which utilizes the highly toxic hydroxyl radical (•OH), has shown tremendous promise. Its antibacterial efficacy, however, is compromised by insufficient H 2 O 2 levels and a near-neutral pH at infection sites. Herein, a glucose-fueled and H 2 O 2 self-supplying •OH nanogenerator (GOx-Fe 3 O 4 @MIL) based on cascade catalytic reactions is successfully constructed by immobilizing glucose oxidase (GOx) on the surface of Fe 3 O 4 NPs-encapsulated MIL88B–NH 2. MIL88B–NH 2 (MIL NPs), a peroxidase-mimicking enzyme, immobilizes and protects GOx while synergistically enhancing the CDT effect of Fe 3 O 4 NPs. GOx can continuously convert glucose into gluconic acid and H 2 O 2. The former reduces the pH value to approximately 4, at which point Fe 3 O 4 @ MIL NPs exhibit the highest reaction activity. The continually produced H 2 O 2 is used for subsequent catalysis of activated Fe 3 O 4 @MIL NPs to generate highly toxic •OH for antibacterial applications, avoiding the direct use of relatively high concentrated and toxic H 2 O 2. In vitro and in vivo results indicate that the designed self-activated nanoreactor can significantly inhibit methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Acinetobacter baumannii (MDR-AB) growth with negligible biotoxicity. [ABSTRACT FROM AUTHOR]

A biodegradable hollow mesoporous Fe/HMnO 2 @DOX-GOD@HA nanoreactor was constructed for GSH-responsive MR imaging, chemotherapy and enhanced bimetallic CDT by self-supplying O 2 /H 2 O 2. [Display omitted] As an endogenous catalytic treatment, chemodynamic therapy (CDT) was attracting considerable attention, but the weak catalytic efficiency of Fenton agents and the non-degradation of nanocarriers severely limited its development. In this work, a biodegradable bimetallic nanoreactor was developed for boosting CDT, in which Fe-doped hollow mesoporous manganese dioxide (HMnO 2) was selected as nanocarrier, and the Fe/HMnO 2 @DOX-GOD@HA nanoprobe was constructed by loading doxorubicin (DOX) and modifying glucose oxidase (GOD) and hyaluronic acid (HA). The glutathione (GSH) responsive degradation of HMnO 2 promoted the release of DOX, by which the release rate significantly increased to 96.6%. Moreover, by the GSH depletion, the reduction of Mn2+/Fe2+ achieved strong bimetallic Fenton efficiency, and the hydroxyl radicals (·OH) generation was further enhanced using the self-supplying H 2 O 2 of GOD. Through the active targeting recognition of HA, the bimetallic nanoreactor significantly enriched the tumor accumulation, by which the enhanced antitumor efficacy was realized. Thus, this work developed biodegradable bimetallic nanoreactor by consuming GSH and self-supplying H 2 O 2 , and provided a new paradigm for enhancing CDT. [ABSTRACT FROM AUTHOR]

Nanofiber technology is leading the revolution of wearable technology and provides a unique capability to fabricate smart textiles. With the novel fabrication technique of electrospinning, nanofibers can be fabricated and then manufactured into a durable conductive string for the application of smart textiles. This paper presents an electrospun nanofiber mesh-based (NF-Felt) string electrode with a conducting polymer coating for an electrochemical enzymatic glucose sensor. The surface area of a nanofiber matrix is a key physical property for enhanced glucose oxidase (GOx) enzyme binding for the development of an electrochemical biosensor. A morphological characterization of the NF-Felt string electrode was performed using scanning electron microscopy (SEM) and compared with a commercially available cotton–polyester (Cot-Pol) string coated with the same conducting polymer. The results from stress–strain testing demonstrated high stretchability of the NF-Felt string. Also, the electrochemical characterization results showed that the NF-Felt string electrode was able to detect a glucose concentration in the range between 0.0 mM and 30.0 mM with a sensitivity of 37.4 μA/mM·g and a detection limit of 3.31 mM. Overall, with better electrochemical performance and incredible flexibility, the NF-Felt-based string electrode is potentially more suitable for designing wearable biosensors for the detection of glucose in sweat. [ABSTRACT FROM AUTHOR]

In this article, we demonstrate an improved efficient fibre sensor with a high sensitivity to measure glucose concentrations in the physiological range of human beings, operating in a broad spectral bandwidth from the near- to mid-infrared. The sensor consists of a dual-peak long period grating (DPLPG) with a period of 150 μm inscribed in an optical fibre with a diameter of 80 μm. The investigation of sensing for refractive index results in a sensitivity of ~−885.7 nm/refractive index unit (RIU) and ~2008.6 nm/RIU in the range of 1.30–1.44. The glucose measurement is achieved by the immobilisation of a layer of enzyme of glucose oxidase (GOD) onto the fibre surface for the selective enhancement of sensitivity for glucose. The sensor can measure glucose concentrations with a maximum sensitivity of −36.25 nm/(mg/mL) in the range of 0.1–3.0 mg/mL. To the best of our knowledge, this is the highest sensitivity ever achieved for a measurement of glucose with a long period grating-based sensor, indicating its potential for many applications including pharmaceutical, biomedical and food industries. [ABSTRACT FROM AUTHOR]

Background: The CRISPR/Cas9 technology is being employed as a convenient tool for genetic engineering of the industrially important filamentous fungus Trichoderma reesei. However, multiplex gene editing is still constrained by the sgRNA processing capability, hindering strain improvement of T. reesei for the production of lignocellulose-degrading enzymes and recombinant proteins. Results: Here, a CRISPR/Cas9 system based on a multiple sgRNA processing platform was established for genome editing in T. reesei. The platform contains the arrayed tRNA−sgRNA architecture directed by a 5S rRNA promoter to generate multiple sgRNAs from a single transcript by the endogenous tRNA processing system. With this system, two sgRNAs targeting cre1 (encoding the carbon catabolite repressor 1) were designed and the precise deletion of cre1 was obtained, demonstrating the efficiency of sgRNAs processing in the tRNA−sgRNA architecture. Moreover, overexpression of xyr1-A824V (encoding a key activator for cellulase/xylanase expression) at the ace1 (encoding a repressor for cellulase/xylanase expression) locus was achieved by designing two sgRNAs targeting ace1 in the system, resulting in the significantly enhanced production of cellulase (up to 1- and 18-fold on the Avicel and glucose, respectively) and xylanase (up to 11- and 41-fold on the Avicel and glucose, respectively). Furthermore, heterologous expression of the glucose oxidase gene from Aspergillus niger ATCC 9029 at the cbh1 locus with the simultaneous deletion of cbh1 and cbh2 (two cellobiohydrolase coding genes) by designing four sgRNAs targeting cbh1 and cbh2 in the system was acquired, and the glucose oxidase produced by T. reesei reached 43.77 U/mL. Besides, it was found the ER-associated protein degradation (ERAD) level was decreased in the glucose oxidase-producing strain, which was likely due to the reduction of secretion pressure by deletion of the major endogenous cellulase-encoding genes. Conclusions: The tRNA−gRNA array-based CRISPR-Cas9 editing system was successfully developed in T. reesei. This system would accelerate engineering of T. reesei for high-level production of enzymes including lignocellulose-degrading enzymes and other recombinant enzymes. Furthermore, it would expand the CRISPR toolbox for fungal genome editing and synthetic biology. [ABSTRACT FROM AUTHOR]

The conjugation of biomolecules to quantum dots has recently gained attention in the field of bionanotechnology. Graphene quantum dots (GQDs) have been employed in various sensing applications due to their tunable fluorescence, controllable size, low cytotoxicity, and high biocompatibility. In this work, sulfur-doped graphene quantum dots (S-GQDs) were conjugated to glucose oxidase (GOx) for the potential detection of glucose. Fluorescent S-GQDs were synthesized via one-step pyrolysis of citric acid and thioglycolic acid at 200 °C. S-GQDs were conjugated to GOx using the carbodiimide/succinimide (EDC/NHS) coupling reaction, followed by purification via centrifugal ultrafiltration. Fluorescence spectroscopy, UV-Vis absorption spectroscopy, and transmission electron microscopy were employed to characterize the S-GQDs and S-GQD-GOx conjugates. The S-GQDs obtained had an average diameter of 49.8 ± 7.4 nm (n = 12) and emitted strong blue fluorescence (λem = 460 nm) when excited with 365-nm UV light. Trinder's assay was used to assess the catalytic activity of free GOx and the S-GQD-GOx conjugates. The S-GQD-GOx conjugates consistently showed significantly greater catalytic activity compared to free GOx. The results obtained open avenues for the fabrication of a sensitive fluorescent GQD-based glucose probe in the future. [ABSTRACT FROM AUTHOR]

A biocompatible BSA@Au/Pt-IR808 nanoplatform with triple-amplification of GOx/CAT/POD was constructed for PTT and enhanced PDT/catalytic therapy. [Display omitted] The weak catalytic activity of nanocatalysts and the insufficient endogenous hydrogen peroxide (H 2 O 2) in tumor microenvironment (TME) seriously restricted the efficacy of catalytic therapy, and the non-degradability of inorganic nanocarriers was also unfavorable for their clinical applications. Herein, by depositing gold nanoparticles (AuNPs) and platinum nanoparticles (PtNPs) with ultrasmall size and modifying photosensitizer (IR808), a biocompatible bovine serum albumin (BSA) nanoplatform (BSA@Au/Pt-IR808) with triple-amplification of enzyme activity was constructed to enhance photodynamic therapy (PDT) and catalytic therapy. Ultrasmall AuNPs possessed glucose oxidase (GOx)-like activity, by which the self-supplying H 2 O 2 accelerated the dual-enzyme activity of peroxidase (POD) and catalase (CAT) of ultrasmall PtNPs, promoting the generation of hydroxyl radical (·OH) and singlet oxygen (1O 2). Compared with BSA-IR808 and BSA@Pt, the yields of 1O 2 and ·OH of BSA@Au/Pt-IR808 increased by 38.2% and 18.6%. Under the combination action of photothermal therapy (PTT)/PDT/catalytic therapy of BSA@Au/Pt-IR808, the cell viability significantly reduced to 12.8%, and the tumors were completely eliminated, demonstrating the enhanced PDT and catalytic therapy against breast cancer. [ABSTRACT FROM AUTHOR]

Diabetes patients need to monitor blood glucose all year round. In this article, a novel scheme is proposed for blood glucose detection. The proposed sensor is based on a U-shaped microfiber prepared using hydrogen-oxygen flame-heating technology, and then 3-aminopropyltriethoxysilane (APTES) and glucose oxidase (GOD) are successively coated on the surface of the U-shaped microfiber via a coating technique. The glucose reacts with the GOD of the sensor surface to produce gluconic acid, which changes the effective refractive index and then shifts the interference wavelength. The structure and morphology of the sensor were characterized via scanning electron microscope (SEM) and confocal laser microscopy (CLM). The experimental results show that the sensitivity of the sensor is as high as 5.73 nm/(mg/mL). Compared with the glucose sensor composed of the same material, the sensitivity of the sensor increased by 329%. The proposed sensor has a broad application prospect in blood glucose detection of diabetic patients due to the advantages of miniaturization, high sensitivity, and good stability. [ABSTRACT FROM AUTHOR]

In this work, the β-cyclodextrins (βCD) grafted on magnetite@polynorepinephrine (Fe3O4@PNE) nanomaterial with glucose oxidase (GOx) from Aspergillus niger was presented. The electroactive nanoplatform was used to construct rapid response and long-live time biosensor for qualitative and quantitative glucose determination. The nanomaterial was deposited on the screen-printed electrode (SPE) and integrated with the potentiostat in tandem with a portable devices. The methodology may affect its relatively low unit cost, miniaturization aspect, and electrode system integrity. The potential usage is intended for advanced diabetes care with a focus on the point-of-care testing idea. The cyclic voltammetry and amperometry were used for electrochemical characterization. The presented SPE/Fe3O4@PNE@βCD-GOx biosensor enabled measurements in a wide range of concentrations (0.1–30.0 mM), an enhanced sensitivity (204.82 µA mM− 1 cm− 2), a low limit of detection (3.2 µM), and a rapid response (2.6 s). Moreover, the proposed sensor achieved long-term stability, up to 11 months. Testing on real samples (human blood, human serum, infusion fluids) showed recovery in range from 95.5 to 98.6%. The outcomes demonstrated that this biosensor has great potential for use in determining the amount of glucose in a biological fluids and commercial products. The novelty of this work would largely consist of the possibility of qualitative and quantitative measurements of glucose in real human samples with a long time stability. This portable system enables mobile diagnostics tests including point-of-care testing idea. Due to the applied β-cyclodextrins on the surface of the novel polynorepinephrine biopolymer coating, selectivity, stability, and sensitivity were improved. [ABSTRACT FROM AUTHOR]

The management of diabetic wounds poses significant challenges due to persistent bacterial infections and chronic inflammation caused by hyperglycemia. Herein, a sequential two‐phase treatment strategy involving a reactive oxygen species (ROS) burst in the first phase for anti‐infection is proposed, followed by a benign level of ROS in the second phase for wound regeneration. To this end, ultra‐small manganese oxide nanodots (BM‐NDs) are incorporated into a gelatin methacrylamide (GelMA) hydrogel via a ROS‐responsive linker to form GelMA@BM dressing. The BM‐NDs catalyze a self‐cascade reaction that decomposes glucose into hydrogen peroxide, generates hydroxyl radicals (·OH), and simultaneously depletes glutathione. Upon application on diabetic wounds, BM‐NDs are rapidly released from the hydrogel due to endogenous ROS exposure, leading to high levels of ·OH that effectively eliminate bacteria and promote macrophage polarization to M1 phenotype, thereby facilitating phagocytosis of bacteria. With the consumption of glucose and degradation of BM‐NDs, ROS in the wound area declines to a benign level, which stimulates polarization of M2 macrophages and promotes wound healing. This two‐phase treatment strategy based on GelMA@BM dressing demonstrates potent antibacterial and pro‐healing efficacy, showcasing its potential for clinical translation. [ABSTRACT FROM AUTHOR]

Phototherapies induced by photoactive nanomaterials have inspired and accentuated the importance of nanomedicine in cancer therapy in recent years. During these light-activated cancer therapies, a nanoagent can produce heat and cytotoxic reactive oxygen species by absorption of light energy for photothermal therapy (PTT) and photodynamic therapy (PDT). However, PTT is limited by the self-protective nature of cells, with upregulated production of heat shock proteins (HSP) under mild hyperthermia, which also influences PDT. To reduce HSP production in cancer cells and to enhance PTT/PDT, small HSP inhibitors that can competitively bind at the ATP-binding site of an HSP could be employed. Alternatively, reducing intracellular glucose concentration can also decrease ATP production from the metabolic pathways and downregulate HSP production from glucose deprivation. Other than reversing the thermal resistance of cancer cells for mild-temperature PTT, an HSP inhibitor can also be integrated into functionalized nanomaterials to alleviate tumor hypoxia and enhance the efficacy of PDT. Furthermore, the co-delivery of a small-molecule drug for direct HSP inhibition and a chemotherapeutic drug can integrate enhanced PTT/PDT with chemotherapy (CT). On the other hand, delivering a glucose-deprivation agent like glucose oxidase (GOx) can indirectly inhibit HSP and boost the efficacy of PTT/PDT while combining these therapies with cancer starvation therapy (ST). In this review, we intend to discuss different nanomaterial-based approaches that can inhibit HSP production via ATP regulation and their uses in PTT/PDT and cancer combination therapy such as CT and ST. [ABSTRACT FROM AUTHOR]

In this work, we investigated the effect of multi-walled carbon nanotubes (MWCNTs) and bio-graphene (bG) on the structure and activity of glucose oxidase (GOx), as well as on the performance of the respective electrochemical glucose biosensors. Various spectroscopic techniques were applied to evaluate conformational changes in GOx molecules induced by the presence of MWCNTs and bG. The results showed that MWCNTs induced changes in the flavin adenine dinucleotide (FAD) prosthetic group of GOx, and the tryptophan residues were exposed to a more hydrophobic environment. Moreover, MWCNTs caused protein unfolding and conversion of α-helix to β-sheet structure, whereas bG did not affect the secondary and tertiary structure of GOx. The effect of the structural changes was mirrored by a decrease in the activity of GOx (7%) in the presence of MWCNTs, whereas the enzyme preserved its activity in the presence of bG. The beneficial properties of bG over MWCNTs on GOx activity were further supported by electrochemical data at two glucose biosensors based on GOx entrapped in chitosan gel in the presence of bG or MWCNTs. bG-based biosensors exhibited a 1.33-fold increased sensitivity and improved reproducibility for determining glucose over the sweat-relevant concentration range of glucose. [ABSTRACT FROM AUTHOR]

The demand for the ubiquitous detection of gases in complex environments is driving the design of highly specific gas sensors for the development of the Internet of Things, such as indoor air quality testing, human exhaled disease detection, monitoring gas emissions, etc. The interaction between analytes and bioreceptors can described as a "lock-and-key", in which the specific catalysis between enzymes and gas molecules provides a new paradigm for the construction of high-sensitivity and -specificity gas sensors. The electrochemical method has been widely used in gas detection and in the design and construction of enzyme-based electrochemical gas sensors, in which the specificity of an enzyme to a substrate is determined by a specific functional domain or recognition interface, which is the active site of the enzyme that can specifically catalyze the gas reaction, and the electrode–solution interface, where the chemical reaction occurs, respectively. As a result, the engineering design of the enzyme electrode interface is crucial in the process of designing and constructing enzyme-based electrochemical gas sensors. In this review, we summarize the design of enzyme-based electrochemical gas sensors. We particularly focus on the main concepts of enzyme electrodes and the selection and design of materials, as well as the immobilization of enzymes and construction methods. Furthermore, we discuss the fundamental factors that affect electron transfer at the enzyme electrode interface for electrochemical gas sensors and the challenges and opportunities related to the design and construction of these sensors. [ABSTRACT FROM AUTHOR]

Disrupting intracellular redox homeostasis combined with immune checkpoint blockade therapy is considered as an effective way to accelerate tumor cell death. However, suppressed tumor immune microenvironment and lower cargo delivery restrict the efficiency of tumor therapy. In this study, a multifunctional tumor microenvironment (TME)‐responsive nanocomposite is constructed using manganese tetroxide (Mn3O4)‐decorated disulfide‐bond‐incorporated dendritic mesoporous organosilica nanoparticles (DMONs) to co‐deliver indoleamine 2,3‐dioxygenase (IDO) inhibitor Epacadostat (IDOi) and glucose oxidase (GOx) following modification with polyethylene glycol. Owing to the responsiveness of Mn3O4‐decorated DMONs to the mildly acidic and glutathione (GSH) overexpressed TME, the nanocomposite can rapidly decompose and release inner contents, thus substantially improving the cargo release ability. Mn3O4 can effectively catalyze hydrogen peroxide (H2O2) decomposition to generate oxygen, enhance the ability of GOx to consume glucose to produce H2O2, and further promote the generation of hydroxyl radicals (•OH) by Mn2+. Furthermore, Mn2+‐mediated GSH depletion and the production of •OH can disrupt intracellular redox homeostasis, contributing to immunogenic cell death. Simultaneously, IDOi can inhibit IDO to reverse inhibited immune response. The results show that self‐amplifying chemodynamic/starvation therapy combined IDO‐blockade immunotherapy synergistically inhibits tumor growth and metastasis in vivo. [ABSTRACT FROM AUTHOR]

Schematic representation for the study of DMSN@Cu-CeO 2 @GOx in regulating the level of H 2 O 2 , glucose and oxygen. [Display omitted] Imbalances in the intracellular environment caused by high levels of glucose, H 2 O 2 , and hypoxia can greatly impact cancer development and treatment. However, there is limited research on regulating the levels of these species simultaneously in tumor cells. Here, a pH-responsive nanozyme-enzyme hybrid system was developed to regulate intracellular glucose, H 2 O 2 and O 2. The system, named DMSN@Cu-CeO 2 @GOx, consists of Cu-CeO 2 nanoparticles and glucose oxidase (GOx) immobilized in dendritic mesoporous silica (DMSN) spheres. GOx efficiently consumes glucose in tumor cells, causing a drop in pH and producing a significant amount of H 2 O 2. Cu-CeO 2 then catalyzes the conversion of H 2 O 2 to O 2 due to its high catalase-like (CAT) activity in weakly acidic conditions. The process was monitored by fluorescence probes, and the mechanism was investigated through fluorescence spectroscopy and confocal laser scanning microscopy. The cascade catalytic system with excellent biocompatibility continuously consumes glucose and elevates the level of O 2 in cells. This hybrid nanomaterial offers a means to regulate the glucose/H 2 O 2 /O 2 levels in cells and may provide insights into starvation therapy by modulating reactive species within cells. [ABSTRACT FROM AUTHOR]

We synthesize a kind of UCNPs@PVP-GOx-PpIX-Fe3+ nanoreactors with rare earth upconversion nanoparticles as the substrate, which can absorb NIR light at 980 nm and convert low-energy photons into high-energy photons, so as to cleverly generating UV radiation induction in vivo , and finally enhance ferroptosis effect through the synergistic starvation/photodynamic therapies. [Display omitted] The limitations of light source limit the clinical application of optical therapy technology. How to improve the application efficiency of radiant light has become the focus of researchers. Here, we synthesize a kind of UCNPs@PVP-GOx-PpIX-Fe3+ (UPGPF) nanoreactors with rare earth upconversion nanoparticles (UCNPs) as the substrate for the enhancement of ferroptosis effect by the synergistic starvation/photodynamic therapies. Firstly, glucose oxidase (GOx) and Fe3+ loaded in UPGPF nanoreactors are used to directly face the problems of insufficient H 2 O 2 level in tumor tissue and low Fenton reaction efficiency. Further, UCNPs can absorb NIR light at 980 nm and convert low-energy photons into high-energy photons, thereby cleverly generating ultraviolet (UV) radiation induction in vivo , which can produce a synergistic effect of enhancing iron death. The in vivo experimental results of breast cancer model mice show that the UPGPF nanoreactors have significant anticancer effect and good biosafety. With the help of the optical conversion characteristics of UCNPs, this kind of treatment idea of building a UV radiation-induced microplatform in the tumor microenvironment, which leads to the synergistic enhancement of iron death effect, provides a promising innovative design strategy for tumor research. [ABSTRACT FROM AUTHOR]

[Display omitted] One of the major challenges in effective cancer therapy arises because of the hypoxic microenvironment in the tumor. This compromises the efficacy of both chemo- and radiotherapy, and thus hinders patient outcomes. To solve this problem, we constructed polydopamine (PDA)-cloaked Fe-based metal organic frameworks (MOFs) loaded with d -arginine (d -Arg), glucose oxidase (GOX), and the chemotherapeutic drug tirapazamine (TPZ). These offer simultaneous multifaceted therapy combining chemodynamic therapy (CDT)/radiotherapy (RT)/starvation therapy (ST)/gas therapy (GT) and chemotherapy. The particles further can act as contrast agents in magnetic resonance imaging. GOX catalyses the conversion of endogenous glucose and O 2 to hydrogen peroxide and gluconic acid, blocking the cells' energy supply and providing ST. With the resultant acidification of the local environment, the breakdown of the MOF releases TPZ (for chemotherapy) and Fe3+, which reacts with H 2 O 2 to produce reactive oxygen species and thus stimulates the conversion of d -Arg to NO for GT and RT sensitization. The PDA coating not only seals the pores and chelates Fe3+ to enhance the T 1 -weighted magnetic resonance imaging (MRI) properties, but also is used to graft folate bovine serum albumin (FA-BSA) and thereby target the tumor site. The combined administration of low doses of X-ray irradiation and nanoparticles reduces the side effects on healthy tissue and can prevent lung metastases in mice. This work highlights the synergistic treatment of osteosarcoma via ST/GT/CDT/RT/MRI/ chemotherapy using a PDA-cloaked MOF system. [ABSTRACT FROM AUTHOR]

A glucose oxidase-mimicking and peroxidase-mimicking dual-nanozymes catalytic cascade system with the capabilities of reshaping the pathological microenvironments of diabetic wound via glucose consumption and acidification is constructed for antibacterial and accelerating wound healing. [Display omitted] Diabetes-related chronic wounds characterized by hyperglycemia and weak alkaline milieu provide numerous advantages for bacteria growth and biofilm formation, setting a myriad of stumbling blocks for wound healing. Therefore, reshaping the spatially and temporally pathological wound microenvironment against bacterial infection is critical to rescue stalled healing progress in diabetes-related chronic wounds. Herein, we demonstrate on the room-temperature construction of a glucose oxidase (GOx)-mimicking and peroxidase (POD)-mimicking dual-nanozymes catalytic cascade system upon the partial reduction of Fe3+ to Fe2+ and the deposition of Au nanoparticles, simultaneously. The as-prepared dual-nanozymes catalytic cascade system possesses the capabilities of reshaping the pathological microenvironments of diabetic wound via glucose consumption and acidification, leading to amplified catalytic cascade activities for sterilization. On the one hand, the GOx-mimicking enzymatic activity of the catalytic cascade system can not only deplete glucose and acidize wound milieu to inhibit bacteria growth, but also utilize the weak alkaline milieu of diabetic wound to provide sufficient H 2 O 2 and a favorable pH for subsequent OH generation. On the other hand, the POD-mimicking enzymatic activity of the catalytic cascade system can continuously produce OH for sterilization under the weak acidic milieu in the presence of abundant H 2 O 2. Benefiting from the simply and mild preparation process and the excellent dual-nanozymes catalytic cascade activities under the deliberate evolved milieus of diabetes-related chronic wounds, our catalytic cascade system exhibits the promising healing effect and clinical translation potential against diabetic wound infection. [ABSTRACT FROM AUTHOR]

Background: Diagnosing a case of tuberculous meningitis (TBM) has always been challenging. Numerous previous studies have demonstrated that cerebrospinal fluid-Adenosine deaminase (CSF-ADA) estimation is useful in the diagnosis of TBM and can differentiate TBM from other types of meningitis. Aims and Objectives: The current study aims to look for a simple, rapid, cost-effective, and specific test to differentiate tubercular etiology from other causes of meningitis. Materials and Methods: A total of 80 patients admitted to the hospital with signs and symptoms of meningitis were selected and divided into two groups: Group 1 (Cases): 40 patients of TBM, Group 2 (Control): 40 patients of pyogenic and viral meningitis. The CSF ADA was estimated by enzymatic method, CSF Protein by turbidimetric method, and CSF Glucose by Glucose oxidase (GOD) and Peroxidase (POD) method. Results: CSF ADA levels (mean ± SD) in the TBM and non-TBM groups were 10.874+7.72 IU/L and 2.44+1.757 IU/L, respectively (highly significant, P<0.001). With the CSF ADA cut off as >6 IU/L, the sensitivity of the test was 95%, and the specificity of 92.5%. On comparison of the values of CSF ADA in the two groups, the t value is -6.75, and the difference in these two values was found to be highly significant (P<0.01). Conclusion: ADA estimation in CSF is a simple, inexpensive, rapid, and specific method for making a diagnosis of tuberculous etiology in TBM. As a screening test, the determination of ADA activity in CSF can help the physician diagnose TBM early and reduce irreversible brain damage and neurologic sequelae by early administration of anti-tuberculous medications. [ABSTRACT FROM AUTHOR]

[Display omitted] Inspired by the way many living organisms utilize chemical/biological reactions to regulate their skin and respond to stimuli in the external environment, we have developed a self-regulating hydrogel design by incorporating chemical reaction networks (CRNs) into biomimetic photonic crystal hydrogels. In this hydrogel system, we used host–guest supramolecular non-covalent bonds between beta-cyclodextrin (β-CD) and ferrocene (Fc) as partial crosslinkers and designed a CRN involving enzyme-fuel couples of horseradish peroxidase (HRP)/H 2 O 2 and glucose oxidase (GOD)/ d -glucose, by which the responsive hydrogel was transformed into a glucose-driven self-regulating hydrogel. Due to the biomimetic structural color in the hydrogel, the progress of the chemical reaction was accompanied by a change in the color of the hydrogel. Based on this principle, the designed supramolecular photonic hydrogel (SPH) can not only achieve naked-eye detection of H 2 O 2 and glucose concentrations with the assistance of a smartphone but also monitor the reactions of HRP and GOD enzymes and determine their activity parameters. The sensitivity and stability of the sensor have been proven. In addition, due to the reversibility of the chemical reaction network, the sensor can be reused, thus having the potential to serve as a low-cost point-of-care sensor. The SPH was ultimately used to detect glucose in human plasma and H 2 O 2 in liver tumor tissue. The results are comparable with commercial assay kits. By redesigning the chemical reaction network in the hydrogel, it is expected to be used for detecting other enzymes or fuels. [ABSTRACT FROM AUTHOR]

Ordered mesoporous carbon CMK-3 sieves with a hexagonal structure and uniform pore size have recently emerged as promising materials for applications as adsorbents and electrodes. In this study, using sucrose as the sustainable carbon source and SBA-15 as a template, CMK-3 sieves are synthesized to form bioelectrocatalytic immobilization matrices for enzymatic biofuel cell (EFC) electrodes. Their electrochemical performance, capacitive features, and the stability of enzyme immobilization are analyzed and compared to commercially available multi-walled carbon nanotubes (MWCNT) using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The anodic reaction in the presence of glucose oxidase (GOx) and ferrocene methanol (FcMeOH) on the sustainably sourced CMK-3-based electrodes produces bioelectrocatalytic current responses at 0.5 V vs. saturated calomel electrode (SCE) that are twice as high as on the MWCNT-based electrodes under saturated glucose conditions. For the cathodic reaction, the MWCNT-based cathode performs marginally better than the CMK-3-based electrodes in the presence of bilirubin oxidase (BOD) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS2−). The CMK-3-based EFCs assembled from the GOx anode and BOD cathode results in a power output of 93 μW cm−2. In contrast, the output power of MWCNT-based EFCs is approximately 53 μW cm−2. The efficiency of CMK-3 as a support material for biofuel cell applications is effectively demonstrated. [ABSTRACT FROM AUTHOR]

Simple Summary: Bees are often fed by beekeepers with supplemented artificial diets. The formulation of an integrative diet for honey bee colonies able to prevent nutritional deficiencies is yet to be found. In this work, the effects of fat-enriched diet (coconut oil) administration in newly emerged and forager bees were tested. Fat supplementation in the honey bee diet determines an increase in newly emerged bees' survival in the short term and an increase in fat content. Further investigations to evaluate the use of such a supplement food to prevent the fat loss of weak families during winter are desirable. Searching for artificial diets positively affecting the survival, immune and antioxidant systems of honey bees is one of main challenges occurring in beekeeping. Among nutrients, lipids play a significant role in insect nutrition as structural components in cell membranes, energy sources and reserves, and are involved in many physiological processes. In this context, the aim of this work was to investigate the effect of 0.5% and 1% coconut oil-enriched diet administration on newly emerged and forager bees survival rate, feed intake, immune system, antioxidant system and both fat and vitellogenin content. In newly emerged bees, supplementation with 1% coconut oil determined a decrease in feed consumption, an increase in survival rate from the 3rd to 14th day of feeding, a short-term decrease in phenoloxidase activity, an increase in body fat and no differences in vitellogenin content. Conversely, supplementation with 0.5% coconut oil determined an increase in survival rate from the 3rd to 15th day of feeding and an increase in fat content in the long term (i.e., 20 days). Regarding the forager bee diet, enrichment with 0.5% and 1% coconut oil only determined an increase in fat content. Therefore, supplementation with coconut oil in honey bee diets at low percentages (0.5 and 1%) determines fat gain. Further investigations to evaluate the use of such supplement foods to prevent the fat loss of weak families during winter are desirable. [ABSTRACT FROM AUTHOR]

Cancer has always posed a significant threat to human health, prompting extensive research into new treatment strategies due to the limitations of traditional therapies. Starvation therapy (ST) has garnered considerable attention by targeting the primary energy source, glucose, utilized by cancer cells for proliferation. Glucose oxidase (GOx), a catalyst facilitating glucose consumption, has emerged as a critical therapeutic agent for ST. However, mono ST alone struggles to completely suppress tumor growth, necessitating the development of synergistic therapy approaches. Metal catalysts possess enzyme-like functions and can serve as carriers, capable of combining with GOx to achieve diverse tumor treatments. However, ensuring enzyme activity preservation in normal tissue and activation specifically within tumors presents a crucial challenge. Nanodelivery systems offer the potential to enhance therapy effectiveness by improving the stability of therapeutic agents and enabling controlled release. This review primarily focuses on recent advances in the mechanism of GOx combined with metal catalysts for synergistic tumor therapy. Furthermore, it discusses various nanoparticles (NPs) constructs designed for synergistic therapy in different carrier categories. Finally, this review provides a summary of GOx-metal catalyst-based NPs (G-M) and offers insights into the challenges associated with G-M therapy, delivery design, and oxygen (O2) supply. [ABSTRACT FROM AUTHOR]

Honey is an attractive natural product with various health benefits. A few honey-based commercial products have successfully been adopted in clinics to improve wound healing. However, screening of other potential sources of medical-grade honey, in particular, honeys from territories with high floral species diversity and high endemicity, is highly needed. The goal of this study was to characterise the physicochemical and antibacterial properties of New Caledonian honey samples (n = 33) and to elucidate the major mechanism of their antibacterial action. Inhibitory antibacterial activity of honeys against Staphylococcus aureus and Pseudomonas aeruginosa was determined with a minimum inhibitory concentration (MIC) assay. Enzymatic activity of glucose oxidase and the content of hydrogen peroxide (H2O2) in honey samples were analysed. Furthermore, total protein content of honeys together with their electrophoretic protein profiles were also determined in the study. The antibacterial efficacy of 24% of the tested honey samples was slightly superior to that of manuka honey with unique manuka factor 15+. The antibacterial activity of catalase-treated honey sample solutions was significantly reduced, suggesting that H2O2 is a key antibacterial compound of diluted honeys. However, the kinetic profiles of H2O2 production in most potent honeys at a MIC value of 6% was not uniform. Under the experimental conditions, we found that a H2O2 concentration of 150 μM in diluted honeys is a critical concentration for inhibiting the growth of S. aureus. In contrast, 150 μM H2O2 in artificial honey solution was not able to inhibit bacterial growth, suggesting a role of phytochemicals in the antibacterial activity of natural honey. In addition, the continuous generation of H2O2 in diluted honey demonstrated an ability to counteract additional bacteria in re-inoculation experiments. In conclusion, the tested New Caledonian honey samples showed strong antibacterial activity, primarily based on H2O2 action, and therefore represent a suitable source for medical-grade honey. [ABSTRACT FROM AUTHOR]

Background: Hepatic ischemia–reperfusion (IR) injury is the primary reason for complications following hepatectomy and liver transplantation (LT). Insulin-induced gene 2 (Insig2) is one of several proteins that anchor the reticulum in the cytoplasm and is essential for metabolism and inflammatory responses. However, its function in IR injury remains ambiguous. Methods: Insig2 global knock-out (KO) mice and mice with adeno-associated-virus8 (AAV8)-delivered Insig2 hepatocyte-specific overexpression were subjected to a 70% hepatic IR model. Liver injury was assessed by monitoring hepatic histology, inflammatory responses, and apoptosis. Hypoxia/reoxygenation stimulation (H/R) of primary hepatocytes and hypoxia model induced by cobalt chloride (CoCl2) were used for in vitro experiments. Multi-omics analysis of transcriptomics, proteomics, and metabolomics was used to investigate the molecular mechanisms underlying Insig2. Results: Hepatic Insig2 expression was significantly reduced in clinical samples undergoing LT and the mouse IR model. Our findings showed that Insig2 depletion significantly aggravated IR-induced hepatic inflammation, cell death and injury, whereas Insig2 overexpression caused the opposite phenotypes. The results of in vitro H/R experiments were consistent with those in vivo. Mechanistically, multi-omics analysis revealed that Insig2 is associated with increased antioxidant pentose phosphate pathway (PPP) activity. The inhibition of glucose-6-phosphate-dehydrogenase (G6PD), a rate-limiting enzyme of PPP, rescued the protective effect of Insig2 overexpression, exacerbating liver injury. Finally, our findings indicated that mouse IR injury could be attenuated by developing a nanoparticle delivery system that enables liver-targeted delivery of substrate of PPP (glucose 6-phosphate). Conclusions: Insig2 has a protective function in liver IR by upregulating the PPP activity and remodeling glucose metabolism. The supplementary glucose 6-phosphate (G6P) salt may serve as a viable therapeutic target for alleviating hepatic IR. [ABSTRACT FROM AUTHOR]

The food enzyme glucose oxidase (β‐d‐glucose:oxygen 1‐oxidoreductase; EC 1.1.3.4) is produced with the genetically modified Saccharomyces cerevisiae strain LALL‐GO by Lallemand Inc. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism, but not from recombinant DNA. It is intended to be used in baking processes. Dietary exposure was estimated to be up to 0.233 mg total organic solids/kg body weight per day in European populations. Since the production strain meets the requirements for the Qualified Presumption of Safety approach and no issues of concern arising from the production process of the food enzyme were identified, the Panel considered that no toxicological studies were necessary. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and two matches were found. The Panel considered that, under the intended conditions of use, the risk of allergic reactions upon dietary exposure to this food enzyme cannot be excluded. The glucose oxidase under assessment shows sequence homology with an allergen from almond, which is listed in the Annex II of the Regulation (EU) No 1169/2011. Other than potential allergic reactions, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use. [ABSTRACT FROM AUTHOR]

This review introduces biosensing research and development activities at the University of Tartu. The biosensor studies were initiated by Jaak Järv and Toomas Tenno at the beginning of the 1980s when a biosensor combining the enzyme glucose oxidase and a cylindrical Clarktype oxygen sensor was constructed in Tartu. Since then, a lot of theoretical research has been carried out in this field, and several original ideas for constructing biosensing devices have been proposed. Different biosensor systems, from singleuse immunosensors to reusable enzyme sensors, have been developed and tested for environmental analysis, food analysis, and clinical and veterinary diagnostics. These solutions have a high potential for practical, everyday applications and automated monitoring. Until now, biosensor research at the University of Tartu has resulted in five patents and more than one hundred scientific papers. Although some biosensor developments have been prototyped, none have been commercialized to date. [ABSTRACT FROM AUTHOR]

Aim. Among the methods of improving biosensor systems, the technique of using multi-enzyme bioselective elements is actively used. Its main idea is that, in addition to the main enzyme, auxiliary enzymes are added to the biosensor membrane, which can improve analytical characteristics or enhance the response of the biosensor to the target analyte. As a model biosensor that we intended to improve, we chose a conductometric biosensor for glucose determination based on glucose oxidase. The main enzyme of this biosensor was glucose oxidase (GOx), which is an enzyme of the oxidase class and catalyzes the reaction of splitting glucose into glucono-1,5-lactone and hydrogen peroxide using oxygen during the reaction. As an auxiliary enzyme, we additionally added catalase (CAT) to improve the characteristics of the sensor. It decomposes the peroxide formed during the first reaction with the participation of GOx into water and O2. This enables to increase the concentration of oxygen in the near-electrode layer, which improves the work of the main enzyme — GOx, and, accordingly, the entire biosensor. Methods. Two enzyme gels, glucose oxidase (GOx) and catalase (CAT) were mixed in a 2:1 ratio and applied to the first pair of electrodes for enzyme immobilization. A BSA protein gel was applied to the second pair of electrodes for reference. Immobilization occurred in glutaraldehyde vapors for 20 minutes, followed by air-drying for 10 minutes. The sensor was then washed for 5 minutes to remove residual GA and other unbound elements. Measurements were conducted in a 2 ml open cell with a 5 mM phosphate buffer solution at pH 6.2. The substrate concentration was adjusted by adding aliquotes of 500 mM D-glucose to working solution. Response time was 2–3 minutes with a 5-minute wash between responses. Response measurement could be done by comparing baseline conductance before and after exposure to the target molecule. Results and Discussion. The initial step in developing of the GOx-CAT bienzyme biosensor was to identify the most effective enzyme immobilization method on the transducer surface. We tested five biosensor variants based on different coimmobilization techniques of GOx and CAT and assessed their key analytical properties. Calibration curves were also generated for each variant to guide the selection process. Ultimately, experiments revealed that immobilization in glutaraldehyde vapors, combining GOx and CAT in a 2:1 ratio within a single-layer membrane, offered the highest sensitivity and wide linear operating range. This method was thus chosen for further development. The next stage of the work was the selection of the optimal concentration of catalase in the membrane. For this, a number of biosensors with different concentrations of catalase in the composition of the bioselective element were made and the sensitivity of these biosensors to the target analyte was compared. Thus, it was shown that the biosensor based on 5% CAT was characterized by the greatest response to the substrate. The difference between mono- and bienzyme biosensors lies in their sensitivity to glucose and their linear detection range. The sensitivity of the bienzyme biosensor (CAT-GOx mixture) was 378 μS/mM, compared to 161 μS/mM for the monoenzyme biosensor (GOx alone). Adding CAT to the biosensor extended its linear range to 1700 μM, compared to 800 μM for the monoenzyme biosensor. Additionally, the minimum detection limit decreased from 16 μM to 8 μM glucose for the monoenzyme and bienzyme biosensors, respectively. Conclusions. The study showed that the addition of catalase as an auxiliary enzyme significantly improved the analytical characteristics of the biosensor based on GOx, in particular, sensitivity, repeatability of measurement results, limits of linear and dynamic ranges of operation. It has been proven that the technology of adding an additional enzyme to the biomembrane of a biosensor can be used to improve the analytical characteristics of biosensors based on oxidases, which in turn will allow their more effective use. [ABSTRACT FROM AUTHOR]