Search

This paper reports a flexible glucose biosensor which is modified by a reduced-swelling and conductive zwitterionic hydrogel enzyme membrane that contains two forms of chemical cross-links. One chemical cross-linking is induced by thermal initiators and forms the basal network of the hydrogel. Another cross-linking is achieved by the coordination interactions between the multivalent metal ion Al3+ and anionic group -COO− of zwitterionic poly-carboxy betaine (pCBMA), which significantly increase the cross-linking density of the zwitterionic hydrogel, improving the reduced-swelling property and reducing the pore size. The better reduced-swelling property and reduced diameters of pores within the zwitterionic hydrogel make less glucose oxidase (GOx) leakage, thus significantly improving the enzyme membrane's service life. By introducing the Al3+ and Cl−, the conductivity of the zwitterionic hydrogel is enhanced approximately 10.4-fold. According to the enhanced conductivity, the reduced-swelling property, and the high GOx loading capacity of the zwitterionic hydrogel, the sensitivity of the biosensor with GOx/pCBMA-Al3+ is significantly improved by 5 times and has a long service life. Finally, the proposed GOx/pCBMA-Al3+ biosensor was applied in non-invasive blood glucose detection on the human body, verifying the capability in practice. [ABSTRACT FROM AUTHOR]

A highly efficient ratiometric electrochemiluminescence (ECL) immunoassay was explored by bidirectionally regulating the ECL intensity of two luminophors. The immunoassay was conducted in a split-type mode consisting of an ECL detection procedure and a sandwich immunoreaction. The ECL detection was executed using a dual-disk glassy carbon electrode modified with two potential-resolved luminophors (g-C3N4-Ag and Ru-MOF-Ag nanocomposites), and the sandwich immunoreaction using glucose oxidase (GOx)-modified SiO2 nanospheres as labels was carried out in a 96-well plate. The Ag nanoparticles (NPs) acted as bifunctional units both for triggering the resonance energy transfer (RET) with g-C3N4 and for accelerating the electron transfer rate of the Ru-MOF-Ag ECL reaction. When the H2O2 catalyzed by GOx in the 96-well plate was transferred to the dual-disk glass carbon electrode, the doped Ag NPs in the two luminophors could be etched, thus destroying the RET between C3N4 and the accelerated reaction to Ru-MOF, resulting in an opposite trend in the ECL signal outputted from the dual disks. Using the ratio of the two signals for quantification, the constructed immunosensor for a model target, i.e. myoglobin, exhibited a low detection limit of 4.7 × 10–14 g/mL. The ingenious combination of ECL ratiometry, bifunctional Ag NPs, and a split-type strategy effectively reduces environmental and human errors, offering a more precise and sensitive analysis for complex samples. [ABSTRACT FROM AUTHOR]

Schematic illustration of the mechanism by which universal NR promotes Fenton/Fenton-like reactions. [Display omitted] Fenton/Fenton-like reaction induced chemical dynamic therapy (CDT) has been widely recognized in tumor therapy. Due to the low efficiency of conversion from high-valent metal ions (M(n+1)+) to low-valent ions (M n+) in the Fenton/Fenton-like catalytic process, enhancing the conversion efficiency safely and effectively would create a great opportunity for the clinical application of CDT. In the study, a universal nanoreactor (NR) consisting of liposome (Lip), tumor cell membrane (CM), and bis(2,4,5-trichloro-6-carboxyphenyl) oxalate (CPPO) is developed to tackle this challenge. The CPPO was first discovered to decompose under weak acidity and H 2 O 2 conditions to generate carboxylic acids (R′COOH) and alcohols (R′OH) with reducibility, which will reduce M(n+1)+ to M n+ and magnify the effect of CDT. Furthermore, glucose oxidase (GOx) was introduced to decompose glucose in tumor and generate H 2 O 2 and glucose acid, which promote the degradation of CPPO, further strengthening the efficiency of CDT, leading to a butterfly effect. This demonstrated that the butterfly effect triggered by NR and GOx encourages Fenton/Fenton-like reactions of Fe 3 O 4 and MoS 2 , thereby enhancing the tumor inhibition effect. The strategy of combining GOx and CPPO to strengthen the Fenton/Fenton-like reaction is a universal strategy, which provides a new and interesting perspective for CPPO in the application of CDT, reflecting the exquisite integration of Fenton chemistry and catalytic medicine. [ABSTRACT FROM AUTHOR]

This study reports a micromachined parylene-C-coated integrated electrode (IDE) sensor fabricated on a polyimide film. Glucose and uric acid within the human sweat concentration range were tested using hydrothermally grown ZnO nanoparticles (NPs) immobilized on the IDE regions of sensors and modified with urate oxidase and glucose oxidase enzymes. Four important sensing parameters, including capacitance, impedance, resistance, and phase, were simultaneously investigated during the dynamic test. The sensor fabrication and characterization of ZnO NPs and ZnO NP formed sensing film were described in detail. The experimental results show that the amount of capacitance change and phase change vs. the concentration variation of glucose and uric acid exhibits an excellent linear regression relationship. On the other hand, the amount of impedance change vs. concentration variation of glucose and uric acid exhibits a power regression relationship. Sensitivities of uric acid and glucose detection based on capacitance changes were 0.1131 pF/µM and 0.7875 pF/µM, respectively. Limits of detection of uric acid and glucose were 1.23 µM and 0.311 µM, respectively. Thus, the developed sensor can be applied to wearable devices for the quantitative analysis of sweat composition in the future. [ABSTRACT FROM AUTHOR]

Tumor cells can survive when detached from the extracellular matrix (ECM) or lose cell–cell connections, a phenomenon known as anoikis-resistance (AR). AR is closely associated with tumor cell metastasis and recurrence, enabling tumor cells to disseminate, migrate, and invade after detachment. To address this issue, a novel intervention method combining intraoperative hemostasis with multifunctional nanozyme driven-enhanced chemodynamic therapy (ECDT) has been proposed, which holds the potential to weaken the AR capability of tumor cells and suppress tumor recurrence. Here, a nanocomposite containing a dendritic mesoporous nanoframework with Cu2+ was developed using an anion-assisted approach after surface PEG grafting and glucose oxidase (GOx) anchoring (DMSN-Cu@GOx/PEG). DMSN-Cu@GOx/PEG was further encapsulated in a thermal-sensitive hydrogel (H@DMSN-Cu@GOx/PEG). DMSN-Cu@GOx/PEG utilizes its high peroxidase (POD) activity to elevate intracellular ROS levels, thereby weakening the AR capability of bladder cancer cells. Additionally, through its excellent catalase (CAT) activity, DMSN-Cu@GOx/PEG converts the high level of hydrogen peroxide (H2O2) catalyzed by intracellular GOx into oxygen (O2), effectively alleviating tumor hypoxia, downregulating hypoxia-inducible factor-1α (HIF-1α) expression, inhibiting epithelial-mesenchymal transition (EMT) processes, and ultimately suppressing the migration and invasion of bladder cancer cells. Interestingly, in vivo results showed that the thermosensitive hydrogel H@DMSN-Cu@GOx/PEG could rapidly gel at body temperature, forming a gel film on wounds to eliminate residual tumor tissue after tumor resection surgery. Importantly, H@DMSN-Cu@GOx/PEG exhibited excellent hemostatic capabilities, effectively enhancing tissue coagulation during post-tumor resection surgery and mitigating the risk of cancer cell dissemination and recurrence due to surgical bleeding. Such hydrogels undoubtedly possess strong surgical application. Our developed novel nanosystem and hydrogel can inhibit the AR capability of tumor cells and prevent recurrence post-surgery. This study represents the first report of using dendritic mesoporous silica-based nanoreactors for inhibiting the AR capability of bladder cancer cells and suppressing tumor recurrence post-surgery, providing a new avenue for developing strategies to impede tumor recurrence after surgery. [ABSTRACT FROM AUTHOR]

Nanofiber (NF) membrane systems that can provide cascade catalytic reaction and ferroptosis induction were developed for oral cancer therapy. Glucose oxidase (GOx) and aminoferrocene (AF) were introduced into the NF system for glucose deprivation/H2O2 generation and OH radical generation, respectively. GOx offers starvation therapy and AF (including iron) provides chemodynamic therapy/ferroptosis for combating oral cancer. GOx (water-soluble) and AF (poorly water-soluble) molecules were successfully entrapped in the NF membrane via an electrospinning process. GOx and AF were incorporated into the polyvinyl alcohol (PVA)-based NF, resulting in PVA/GOx/AF NF with fast disintegration and immediate drug-release properties. In oral squamous cell carcinoma (YD-9 cells), the PVA/GOx/AF NF group exhibited higher cytotoxicity, antiproliferation potential, cellular ROS level, apoptosis induction, lipid ROS level, and malondialdehyde level compared to the other NF groups. The electrospun PVA/GOx/AF NF can be directly applied to oral cancer without causing pain, offering starvation/chemodynamic therapy and ferroptosis induction. [ABSTRACT FROM AUTHOR]

Solanum xanthocarpum fruits are used in the treatment of cough, fever, and heart disorders. It possesses antipyretic, hypotensive, antiasthmatic, aphrodisiac and antianaphylactic properties. In the present study, 24 elicitors (both biotic and abiotic) were used to enhance the production of glycoalkaloids in cell cultures of S. xanthocarpum. Four concentrations of elicitors were added into the MS culture medium. The maximum accumulation (5.56-fold higher than control) of demissidine was induced by sodium nitroprusside at 50 mM concentration whereas the highest growth of cell biomass (4.51-fold higher than control) stimulated by systemin at 30 mM concentration. A total of 17 genes of biosynthetic pathways of glycoalkaloids were characterized from the cells of S. xanthocarpum. The greater accumulation of demissidine was confirmed with the expression analysis of 11 key biosynthetic pathway enzymes e.g., acetoacetic-CoA thiolase, 3- hydroxy 3-methyl glutaryl synthase, β-hydroxy β-methylglutaryl CoA reductase, mevalonate kinase, farnesyl diphosphate synthase, squalene synthase, squalene epoxidase, squalene-2,3- epoxide cyclase, cycloartenol synthase, UDP-glucose: solanidine glucosyltransferase and UDP-rhamnose: solanidine rhamno-galactosyl transferase. The maximum expression levels of UDP-rhamnose: solanidine rhamno-galactosyl transferase gene was recorded in this study. • Solanum xanthocarpum fruits are used in the treatment of cough, and heart disorders. • It possesses antipyretic, hypotensive, and aphrodisiac properties. • Elicitation is used for increasing the production of secondary metabolites. • Four concentrations of elicitors were added into the MS culture medium. • The maximum accumulation of demissidine was induced by sodium nitroprusside. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (AuNPs) have great potential as biosensors for glucose detection due to their high sensitivity, as well as their extraordinary physical and chemical properties that improve compatibility with different biorecognition molecules, such as glucose oxidase (GOx). In this work the D-glucose quantification was determined by using the traditional technique based on biochemical reaction of GOx and AuNPs functionalized with polyvinylpirrolidone (PVP) polymer and the enzyme. The AuNPs-PVP-GOx nanocomplexes were characterized by ultraviolet-visible (UV-Visible), Infrared (FTIR), and Raman spectroscopies, as well as scanning electron microscopy (SEM), Z potential, dynamic light scattering (DLS), and thermogravimetry analysis (TGA). In general, these techniques showed significant differences after each functionalization stage with PVP and GOx, for instance it was observed: the presence of different functional groups, an increase of hydrodynamic diameter from 48.60 to 198.77 nm, a shift of the band absorption to larger wavelength, a change in the surface potential and weight loss, and in the morphology of the nanocomplex, which confirm the functionalization. In addition, the enzymatic activity of the AuNPs-PVP-GOx was confirmed through the detection of triiodide ions by UV-Visible spectrophotometry, coming from the oxidation reaction of iodide ions in the presence of H2O2. Furthermore, the nanocomplex synthesized by passive adsorption was evaluated as a possible biosensor for the quantification of D-glucose using a colorimetric assay, obtaining greater sensitivity than the traditional method. These findings indicate that PVP can be used as a linkage medium between AuNPs and GOx, which in turn can be used as a biosensor for the detection of D-glucose at low concentrations in biological fluids. [ABSTRACT FROM AUTHOR]

The hyperglycemic pathophysiological environment in diabetic wounds is a major obstacle that impedes the healing process. Glucose‐responsive wound healing materials are a promising approach to address this challenge. In this study, complex coacervate‐based protocells are introduced for diabetic wound healing. By employing a microfluidic chip with an external mechanical vibrator, uniform coacervate microdroplets are generated via electrostatic interactions between diethylaminoethyl‐dextran and double‐stranded DNA. The spontaneous assembly of a phospholipid membrane on the droplet surface enhances its biocompatibility. Glucose oxidase and copper peroxide nanodots are integrated into microdroplets, enabling a glucose‐responsive cascade that produces hydroxyl radicals as antibacterial agents. These features contribute to efficient antibacterial activity and wound healing in diabetic mice. The present protocells facilitate intelligent wound management, and the design of cascade catalytic coacervates can contribute to the development of various smart vehicles for drug delivery. [ABSTRACT FROM AUTHOR]

Wearable sensors, specifically microneedle sensors based on electrochemical methods, have expanded extensively with recent technological advances. Today's wearable electrochemical sensors present specific challenges: they show significant modulus disparities with skin tissue, implying possible discomfort in vivo, especially over extended wear periods or on sensitive skin areas. The sensors, primarily based on polyethylene terephthalate (PET) or polyimide (PI) substrates, might also cause pressure or unease during insertion due to the skin's irregular deformation. To address these constraints, we developed an innovative, wearable, all-fiber-structured electrochemical sensor. Our composite sensor incorporates polyurethane (PU) fibers prepared via electrospinning as electrode substrates to achieve excellent adaptability. Electrospun PU nanofiber films with gold layers shaped via thermal evaporation are used as base electrodes with exemplary conductivity and electrochemical catalytic attributes. To achieve glucose monitoring, gold nanofibers functionalized by gold nanoflakes (AuNFs) and glucose oxidase (GOx) serve as the working electrode, while Pt nanofibers and Ag/AgCl nanofibers serve as the counter and reference electrode. The acrylamide-sodium alginate double-network hydrogel synthesized on electrospun PU fibers serves as the adhesive and substance-transferring layer between the electrodes. The all-fiber electrochemical sensor is assembled layer-by-layer to form a robust structure. Given the stretchability of PU nanofibers coupled with a high specific surface area, the manufactured porous microneedle glucose sensor exhibits enhanced stretchability, superior sensitivity at 31.94 μA (lg(mM))−1 cm−2, a broad detection range (1–30 mM), and a significantly low detection limit (1 mM, S/N = 3), as well as satisfactory biocompatibility. Therefore, the novel electrochemical microneedle design is well-suited for wearable or even implantable continuous monitoring applications, thereby showing promising significant potential within the global arena of wearable medical technology. [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]

Tumor starvation therapy utilizing glucose oxidase (GOx), has gained traction due to its non-invasive and bio-safe attributes. However, its effectiveness is often hampered by severe hypoxia in the tumor microenvironment (TME), limiting GOx's catalytic activity. To address this issue, a multifunctional nanosystem based on mesoporous polydopamine nanoparticles (MPDA NPs) was developled to alleviate TME hypoxia. This nanosystem integrated GOx modification and oxygenated perfluoropentane (PFP) encapsulation to address hypoxia-related challenges in the TME. Under NIR laser irradiation, the MPDA NPs exhibit significant photothermal conversion efficacy, activating targeted tumor photothermal therapy (PTT), while also serving as proficient photoacoustic (PA) imaging agents. The ensuing temperature rise facilitates oxygen (O 2) release and induces liquid-gas conversion of PFP, generating microbubbles for enhanced ultrasound (US) imaging signals. The supplied oxygen alleviates local hypoxia, thereby enhancing GOx-mediated endogenous glucose consumption for tumor starvation. Overall, the integration of ultrasound/photoacoustic dual imaging-guided PTT and starvation therapy within MPDA-GOx@PFP@O 2 nanoparticles (MGPO NPs) presents a promising platform for enhancing the efficacay of tumor treatment by overcoming the complexities of the TME. A multifunctional MPDA-based theranostic nanoagent was developed for US/PAI imaging-guided PTT and starvation therapy against tumor hypoxia by direct O 2 delivery. The incorporation of oxygenated perfluoropentane (PFP) within the mesoporous structure of MGPO not only enables efficient US imaging but also helps in alleviating tumor hypoxia. Moreover, the strong near-infrared (NIR) absorption of MGPO NPs promote the generation of PFP microbubbles and release of oxygen, thereby enhancing US imaging and GOx-mediated starvation therapy. Such a multifunctional nanosystem leverages synergistic effects to enhance therapeutic efficacy while incorporating US/PA imaging for precise visualization of the tumor. [Display omitted] [ABSTRACT FROM AUTHOR]

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

This study synthesized Fe-doped dopamine carbon dots (Fe-DACDs) as a reducing agent and template hybrid Au and Pt nanoparticles (Au@Pt/Fe-DACDs). Au@Pt/Fe-DACDs with core–shell structures show strong peroxidase (POD)-like activity at physiological pH. A colorimetric and surface-enhanced Raman scattering (SERS) dual-mode detection system for glucose in human serum was constructed by combining Au@Pt/Fe-DACDs with natural glucose oxidase (GOx). The cascade catalysis reactions convert glucose into hydrogen peroxide (H2O2), and then, the Au@Pt/Fe-DACDs as both POD-like nanozyme and Raman-enhancers oxidize colorless and weak Raman-active 3,3′,5,5′-tetramethylbenzidine (TMB) into blue and strong Raman-active ox-TMB. The linear response ranges of glucose are from 0.02 to 1 mM, with a detection limit of 2.3 μM for colorimetric detection and 0.01 mM to 0.7 mM with a detection limit of 1.4 μM for SERS sensors. Glucose content in human serum samples was successfully assayed with a good recovery from 97.6 to 105.3%. Overall, these results demonstrate a new way of designing biological detection systems based on SERS and colorimetric dual-mode sensing. [ABSTRACT FROM AUTHOR]

Graphene and its variants exhibit excellent electrical properties for the construction of enzymatic interfaces. In particular, the direct electron transfer of glucose oxidase on the electrode surface is a very important issue in the development of enzyme-based bioelectrodes. However, the number of studies conducted to assess how pristine graphene forms different interfaces with other carbon materials is insufficient. Enzyme-based electrodes (formed using carbon materials) have been extensively applied because of their low manufacturing costs and easy production techniques. In this study, the characteristics of a single-walled carbon nanotube/graphene-combined enzyme interface are analyzed at the atomic level using molecular dynamics simulations. The morphology of the enzyme was visualized using an elastic network model by performing normal-mode analysis based on electrochemical and microscopic experiments. Single-carbon electrodes exhibited poorer electrical characteristics than those prepared as composites with enzymes. Furthermore, the composite interface exhibited 4.61- and 2.45-fold higher direct electron efficiencies than GOx synthesized with single-carbon nanotubes and graphene, respectively. Based on this study, we propose that pristine graphene has the potential to develop glucose oxidase interfaces and carbon-nanotube–graphene composites for easy fabrication, low cost, and efficient electrode structures for enzyme-based biofuel cells. [ABSTRACT FROM AUTHOR]

Simple Summary: Spodoptera frugiperda is a significant global agricultural pest, particularly fond of maize. In agroecosystems, the interactions among plants, phytophagous insects, and their natural enemies form a complex web at three trophic levels, with volatile compounds playing a pivotal role in these interactions. Phytophagous insects utilize plant volatiles as chemical cues to accurately identify and locate their hosts. Furthermore, herbivore-induced plant volatiles (HIPVs) act as critical chemical messengers and play an essential role in mediating interactions across the three trophic levels. These interactions include inducing defense mechanisms in neighboring plants, attracting natural enemies to help suppress pest populations, or directly producing repellent substances to deter pests. Oral secretions (OS) play a vital role in this interaction, acting as a critical signaling conduit that modulates plant responses. In this study, the major agricultural pest S. frugiperda was examined, with the GOX gene targeted as a molecular focus. The findings indicate that the GOX gene influences HIPV emission in maize, providing valuable insights into plant–insect interaction mechanisms and laying a foundation for innovative plant protection strategies. The intricate relationships between plants and insects are essential for understanding ecological dynamics. Among these interactions, HIPVs serve as a pivotal defense mechanism. Our findings reveal the highly conserved nature of the GOX gene within the Lepidoptera order, highly expressed in the salivary glands of S. frugiperda, and its role in mediating maize's defense responses. Notably, salivary GOX activity expression significantly decreases subsequent gene knockout. The presence of GOX in the saliva of S. frugiperda significantly modulates the emission of HIPVs during maize consumption. This research delineates that GOX selectively inhibits the emission of certain green leaf volatiles (GLVs) while concurrently enhancing the release of terpene volatiles. This study unveils a novel mechanism whereby S. frugiperda utilizes GOX proteins in OS to modulate volatile emissions from maize, offering fresh perspectives on the adaptive evolution of phytophagous insects and their interactions with their preferred host plants. [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]

Diabetic wound healing is a great clinical challenge due to the microenvironment of hyperglycemia and high pH value, bacterial infection and persistent inflammation. Here, we develop a cascade nanoreactor hydrogel (Arg@Zn-MOF-GOx Gel, AZG-Gel) with arginine (Arg) loaded Zinc metal organic framework (Zn-MOF) and glucose oxidase (GOx) based on chondroitin sulfate (CS) and Pluronic (F127) to accelerate diabetic infected wound healing. GOx in AZG-Gel was triggered by hyperglycemic environment to reduce local glucose and pH, and simultaneously produced hydrogen peroxide (H 2 O 2) to enable Arg-to release nitric oxide (NO) for inflammation regulation, providing a suitable microenvironment for wound healing. Zinc ions (Zn2+) released from acid-responsive Zn-MOF significantly inhibited the proliferation and biofilm formation of S.aureus and E.coli. AZG-Gel significantly accelerated diabetic infected wound healing by down-regulating pro-inflammatory tumor necrosis factor (TNF)-α and interleukin (IL)-6, up-regulating anti-inflammatory factor IL-4, promoting angiogenesis and collagen deposition in vivo. Collectively, our nanoreactor cascade strategy combining "endogenous improvement (reducing glucose and pH)" with "exogenous resistance (anti-bacterial and anti-inflammatory)" provides a new idea for promoting diabetic infected wound healing by addressing both symptoms and root causes. A cascade nanoreactor (AZG-Gel) is constructed to solve three key problems in diabetic wound healing, namely, hyperglycemia and high pH microenvironment, bacterial infection and persistent inflammation. Local glucose and pH levels are reduced by GOx to provide a suitable microenvironment for wound healing. The release of Zn2+ significantly inhibits bacterial proliferation and biofilm formation, and NO reduces wound inflammation and promotes angiogenesis. The pH change when AZG-Gel is applied to wounds is expected to enable the visualization of wound healing to guide the treatment of diabetic wound. Our strategy of "endogenous improvement (reducing glucose and pH)" combined with "exogenous resistance (anti-bacterial and anti-inflammatory)" provides a new way for promoting diabetic wound healing. [Display omitted] [ABSTRACT FROM AUTHOR]

Yuan Yuan,1,* Mingyi Hou,2,* Xiaoning Song,1 Xintao Yao,1 Xuerui Wang,1 Xiangjun Chen,2 Shengnan Li1 1School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin, 300401, People’s Republic of China; 2School of Pharmacy, Shandong New Drug Loading & Release Technology and Preparation Engineering Laboratory, Binzhou Medical University, Yantai, 264003, People’s Republic of China*These authors contributed equally to this workCorrespondence: Shengnan Li; Xiaoning Song, School of Chemical Engineering and Technology, Hebei University of Technology, Xiping Road, Tianjin, 300401, People’s Republic of China, Email lisn027@hebut.edu.cn; songxn123@hebut.edu.cnBackground: With the rapid development of nanotechnology, constructing a multifunctional nanoplatform that can deliver various therapeutic agents in different departments and respond to endogenous/exogenous stimuli for multimodal synergistic cancer therapy remains a major challenge to address the inherent limitations of chemotherapy.Methods: Herein, we synthesized hollow mesoporous Prussian Blue@zinc phosphate nanoparticles to load glucose oxidase (GOx) and DOX (designed as HMPB-GOx@ZnP-DOX NPs) in the non-identical pore structures of their HMPB core and ZnP shell, respectively, for photothermally augmented chemo-starvation therapy.Results: The ZnP shell coated on the HMPB core, in addition to providing space to load DOX for chemotherapy, could also serve as a gatekeeper to protect GOx from premature leakage and inactivation before reaching the tumor site because of its degradation characteristics under mild acidic conditions. Moreover, the loaded GOx can initiate starvation therapy by catalyzing glucose oxidation while causing an upgradation of acidity and H2O2 levels, which can also be used as forceful endogenous stimuli to trigger smart delivery systems for therapeutic applications. The decrease in pH can improve the pH-sensitivity of drug release, and O2 can be supplied by decomposing H2O2 through the catalase-like activity of HMPBs, which is beneficial for relieving the adverse conditions of anti-tumor activity. In addition, the inner HMPB also acts as a photothermal agent for photothermal therapy and the generated hyperthermia upon laser irradiation can serve as an external stimulus to further promote drug release and enzymatic activities of GOx, thereby enabling a synergetic photothermally enhanced chemo-starvation therapy effect. Importantly, these results indicate that HMPB-GOx@ZnP-DOX NPs can effectively inhibit tumor growth by 80.31% and exhibit no obvious systemic toxicity in mice.Conclusion: HMPB-GOx@ZnP-DOX NPs can be employed as potential theranostic agents that incorporate multiple therapeutic modes to efficiently inhibit tumors. Keywords: Prussian Blue, glucose oxidase, co-delivery system, photothermal therapy, chemotherapy

AbstractIntegration of gold nanoparticles onto electrochemical biosensor electrodes has been widely conducted to improve the performance of biosensors. Gold nanospikes (AuNS), as one of the gold nanoparticle morphologies, can be integrated into biosensors through electrodeposition and has the potential to immobilize bioreceptor on biosensors using the self-assembled monolayer (SAM) method. This paper examines the potential of AuNS-deposited Screen-Printed Carbon Electrodes (SPCEs) on immobilizing enzymes as label-based electrochemical biosensor by evaluating the optimum parameter for glucose oxidase (GOx) enzyme immobilization on the SPCE that consists of incubation time and concentration of SAM molecule—L-cysteine—and GOx enzyme, then reviews its performances. The developed biosensor exhibits excellent performance in detecting glucose (linear range of 0.2–15 mM and limit of detection (LOD) of 116 µM), with good selectivity against uric acid, urea, ascorbic acid, dopamine, and lactic acid, and superiority towards gold nanosphere modified biosensor.

AuPt@MnO 2 nanoplatform with CAT/POD/Gox-like activities was constructed for NIR-II photothermal-promoted catalytic therapy. [Display omitted] Bimetallic nanozymes exhibited multi-enzyme activities, but glutathione (GSH) overexpression and weak catalytic capability restricted their catalytic therapeutic performance. Thus, this study developed a smart nanozyme (AuPt@MnO 2) with a core–shell structure by coating manganese dioxide (MnO 2) on the gold-platinum (AuPt) nanozyme (AuPt@MnO 2) surface to enhance catalytic therapy. In this nanozyme, AuPt possessed triple-enzyme activities, i.e., catalase, peroxidase, and glucose oxidase, which greatly improved oxygen, hydroxyl radicals (·OH), and hydrogen peroxide generation, due to cyclic reactions. Moreover, GSH consumption degraded the MnO 2 shell, which then enhanced ·OH generation of Mn2+. More importantly, the near-infrared-II (NIR-II) photothermal performance of AuPt@MnO 2 with a high conversion efficiency of 38.7 % further promoted multi-enzyme activities and enhanced catalytic therapy. Moreover, combining NIR-II photothermal therapy and enhancing catalytic therapy decreased the cell viability to 10.8 %, and thereby, the tumors were cleared. Thus, the AuPt@MnO 2 smart nanoplatform developed in this study exhibited NIR-II photothermal-promoted multi-enzyme activities and excellent antitumor efficacy, which will be promising for enhancing catalytic therapy. [ABSTRACT FROM AUTHOR]

[Display omitted] As different monosaccharides exhibit different redox characteristics, this paper presented a novel colorimetric sensor array based on the glucose oxidase-like (GOx-like) activity of Au nanoparticles (NPs) for monosaccharides identification. AuNPs can use O 2 , ABTS+•, or [Ag(NH 3) 2 ]+ as an electron acceptor to catalyze the oxidation of monosaccharides in different velocity, resulting in cross-responsive signals. The current sensor array can distinguish between different monosaccharides or their mixtures through linear discriminant analysis (LDA) and hierarchical clustering analysis (HCA). Moreover, the glucose and fructose concentrations can be estimated simultaneously using a neural network regression model based on the sensor array. This method shows potential for monosaccharide detection in industrial, medical, and biological applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Multidrug-resistant (MDR) bacteria-infected wound healing remains greatly challenging, especially in diabetic patients. Herein, a novel nano-drug delivery based on endogenous glucose-driven cascade reaction is proposed for boosting MDR bacteria-infected diabetic wound healing with high efficacy by improving wound microenvironment and enhancing photodynamic antibacterial activity. The composite nanoagent is first self-assembled by integrating berberine (B BR) and epigallocatechin gallate (E GCG) from natural plant extracts, named as BE NPs , which is successively coated with manganese dioxide nanoshells (M nO 2 NSs) and glucose oxidase (G OX) to form the final BEMG NPs. The cascade reaction is triggered by glucose at the wound site of diabetes which is specifically catalyzed by GOX in the BEMG NPs to produce gluconic acid and hydrogen peroxide (H 2 O 2). That is subsequently to decompose MnO 2 NSs in the BEMG NPs to generate oxygen (O 2). The BEMG NPs as photosensitizers effectively produce reactive oxygen species (ROS) to enhance the eradication of bacteria with the assistance of O 2. Under the synergistic function of the cascaded reaction, the BEMG NPs present excellent antibacterial efficacy even for MDR bacteria. The in vivo experiments explicitly validate that the constructed nano-drug delivery can augment the MDR bacteria-infected diabetic wound healing with excellent biosafety. The as-proposed strategy provides an instructive way to combat ever-threatening MDR bacteria, which particularly is beneficial for diabetic patients. [ABSTRACT FROM AUTHOR]

[Display omitted] Here, we report the preparation of a novel Janus nanoparticle with opposite Ir and mesoporous silica nanoparticles through a partial surface masking with toposelective modification method. This nanomaterial was employed to construct an enzyme-powered nanomachine with self-propulsion properties for on-command delivery. The cargo-loaded nanoparticle was provided with a pH-sensitive gate and unit control at the mesoporous face by first attaching boronic acid residues and further immobilization of glucose oxidase through reversible boronic acid esters with the carbohydrate residues of the glycoenzyme. Addition of glucose leads to the enzymatic production of H 2 O 2 and gluconic acid, being the first compound catalytically decomposed at the Ir nanoparticle face producing O 2 and causing the nanomachine propulsion. Gluconic acid leads to a pH reduction at the nanomachine microenvironment causing the disruption of the gating mechanism with the subsequent cargo release. This work demonstrates that enzyme-mediated self-propulsion improved release efficiency being this nanomotor successfully employed for the smart release of Doxorubicin in HeLa cancer cells. [ABSTRACT FROM AUTHOR]

The treatment of diabetic periodontitis poses a significant challenge due to the presence of local inflammation characterized by excessive glucose concentration, bacterial infection, and high oxidative stress. Herein, mesoporous silica nanoparticles (MSN) are embellished with gold nanoparticles (Au NPs) and loaded with manganese carbonyl to prepare a carbon monoxide (CO) enhanced multienzyme cooperative hybrid nanoplatform (MSN‐Au@CO). The Glucose‐like oxidase activity of Au NPs catalyzes the oxidation of glucose to hydrogen peroxide (H2O2) and gluconic acid，and then converts H2O2 to hydroxyl radicals (•OH) by peroxidase‐like activity to destroy bacteria. Moreover, CO production in response to H2O2, together with Au NPs exhibited a synergistic anti‐inflammatory effect in macrophages challenged by lipopolysaccharides. The underlying mechanism can be the induction of nuclear factor erythroid 2‐related factor 2 to reduce reactive oxygen species, and inhibition of nuclear factor kappa‐B signaling to diminish inflammatory response. Importantly, the antibacterial and anti‐inflammation effects of MSN‐Au@CO are validated in diabetic rats with ligature‐induced periodontitis by showing decreased periodontal bone loss with good biocompatibility. To summarize, MSN‐Au@CO is fabricate to utilize glucose‐activated cascade reaction to eliminate bacteria, and synergize with gas therapy to regulate the immune microenvironment, offering a potential direction for the treatment of diabetic periodontitis. [ABSTRACT FROM AUTHOR]

Due to the limitations of single-model tumor therapeutic strategies, multimodal combination therapy have become a more favorable option to enhance efficacy by compensating for its deficiencies. However, in nanomaterial-based multimodal therapeutics for tumors, exploiting synergistic interactions and cascade relationships of materials to achieve more effective treatments is still a great challenge. Based on this, we constructed a nanoplatform with a "triple-linkage" effect by cleverly integrating polydopamine (PDA), silver nanoparticles (AgNPs), and glucose oxidase (GOx) to realize enhanced photothermal therapy (PTT) and activatable metal ion therapy (MIT) for hepatocellular carcinoma (HCC) treatment. First, the non-radiative conversion of PDA under light conditions was enhanced by AgNPs, which directly enhanced the photothermal conversion efficiency of PDA. In addition, GOx reduced the synthesis of cellular heat shock proteins by interfering with cellular energy metabolism, thereby enhancing cellular sensitivity to PTT. On the other hand, H2O2, a by-product of GOx-catalyzed glucose, could be used as an activation source to activate non-toxic AgNPs to release cytotoxic Ag+, achieving activatable Ag+-mediated MIT. In conclusion, this nanosystem achieved efficient PTT and MIT for HCC by exploiting the cascade effect among PDA, AgNPs, and GOx, providing a novel idea for the design of multimodal tumor therapeutic systems with cascade regulation. [ABSTRACT FROM AUTHOR]

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

In this paper, a novel fluorescent detection method for glucose and lactic acid was developed based on fluorescent iron nanoclusters (Fe NCs). The Fe NCs prepared using hemin as the main raw material exhibited excellent water solubility, bright red fluorescence, and super sensitive response to hydrogen peroxide (H2O2). This paper demonstrates that Fe NCs exhibit excellent peroxide-like activity, catalyzing H2O2 to produce hydroxyl radicals (•OH) that can quench the red fluorescence of Fe NCs. In this paper, a new type of glucose sensor was established by combining Fe NCs with glucose oxidase (GluOx). With the increase in glucose content, the fluorescence of Fe NCs decreases correspondingly, and the glucose content can be detected in the scope of 0–200 μmol·L−1 (μM). Similarly, the lactic acid sensor can also be established by combining Fe NCs with lactate oxidase (LacOx). With the increase in lactic acid concentration, the fluorescence of Fe NCs decreases correspondingly, and the lactic acid content can be detected in the range of 0–100 μM. Furthermore, Fe NCs were used in the preparation of gel test strip, which can be used to detect H2O2, glucose and lactic acid successfully by the changes of fluorescent intensity. [ABSTRACT FROM AUTHOR]

Bacterial-based antitumor immunity has become a promising strategy to activate the immune system for fighting cancer. However, the potential application of bacterial therapy is hindered by the presence of instability and susceptibility to infections within bacterial populations. Furthermore, monotherapy is ineffective in completely eliminating complex cancer with multiple contributing factors. In this study, based on our discovery that spore shell (SS) of Bacillus coagulans exhibits excellent tumor-targeting ability and adjuvant activity, we develop a biomimetic spore nanoplatform to boost bacteria-mediated antitumor therapy, chemodynamic therapy and antitumor immunity for synergistic cancer treatment. In detail, SS is separated from probiotic spores and then attached to the surface of liposome (Lipo) that was loaded with hemoglobin (Hb), glucose oxidase (GOx) and JQ1 to construct SS@Lipo/Hb/GOx/JQ1. In tumor tissue, highly toxic hydroxyl radicals (• OH) are generated via sequential catalytic reactions: GOx catalyzing glucose into H2 O2 and Fe2+ in Hb decomposing H2O2 into • OH. The combination of • OH and SS adjuvant can improve tumor immunogenicity and activate immune system. Meanwhile, JQ1-mediated down-regulation of PD-L1 and Hb-induced hypoxia alleviation synergistically reshape immunosuppressive tumor microenvironment and potentiate immune response. In this manner, SS@Lipo/Hb/GOx/JQ1 significantly suppresses tumor growth and metastasis. To summarize, the nanoplatform represents an optimum strategy to potentiate bacteria-based cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Simple Summary: Varroa destructor is a mite that parasitises honeybee hives, weakening colonies and transmitting viruses. Beekeepers apply acaricide treatments to bee colonies to limit the spread of Varroa and the resulting negative effects on bee health. Oxalic acid treatment is the most widely applied, but little is known about its potential effects on the physiology of bees, particularly their immune system. This study investigated the short-term effects of oxalic acid treatment on the immune and antioxidant systems of house bees (i.e., glucose oxidase, phenoloxidase, glutathione S-transferase, catalase activities, and vitellogenin content). Residual concentrations of oxalic acid on the bees' external body and in the haemolymph were also measured. The results showed that the treatment did not affect the concentration of oxalic acid in the haemolymph, in which it was constitutively present. Residues of oxalic acid remained on the outer body of the bees for up to 48 h after treatment. Both glucose oxidase activity and vitellogenin concentration were affected by the treatment, increasing significantly after 48 and 24 h, respectively. No effects were observed on the other parameters investigated (phenoloxidase, glutathione S-transferase, and catalase activities). Honeybees (Apis mellifera L.) have to face many challenges, including Varroa destructor infestation, associated with viral transmission. Oxalic acid is one of the most common treatments against Varroa. Little is known about the physiological effects of oxalic acid, especially those on honeybees' immune systems. In this study, the short-term effects (0–96 h) of oxalic acid treatment on the immune system components (i.e., glucose oxidase, phenoloxidase, glutathione S-transferase, catalase activities, and vitellogenin contents) of house bees were preliminarily investigated. Oxalic acid contents of bee bodies and haemolymphs were also measured. The results confirm that oxalic acid is constitutively present in bee haemolymphs and its concentration is not affected by treatment. At 6 h after the treatment, a maximum peak of oxalic acid content was detected on bees' bodies, which gradually decreased after that until physiological levels were reached at 48 h. In the immune system, the oxalic acid treatment determined a peak in glucose oxidase activity at 48 h, indicating a potential defence response and an increase in vitellogenin content at 24 h. No significant changes were recorded in phenoloxidase, glutathione S-transferase, and catalase activities. These results suggest a time-dependent response to oxalic acid, with potential immune system activation in treated bees. [ABSTRACT FROM AUTHOR]

Morus sp. (mulberry) has a long tradition of use as a medicinal treatment, including for cardiovascular disease and type 2 diabetes, being shown to have antioxidant properties and to promote wound healing. Extracellular vesicles (EVs) are sub-micron, membrane-enclosed particles that were first identified in mammalian bodily fluids. EV-like particles have been described in plants (PDVs) and shown to have similar characteristics to mammalian EVs. We hypothesised that some of the health benefits previously attributed to the fruit of Morus sp. could be due to the release of PDVs. We isolated PDVs from Morus nigra and Morus alba via ultracentrifugation and incubated THP-1 monocytes, differentiated THP-1 macrophages, or HMEC-1 endothelial cells with pro-oxidant compounds DMNQ (THP-1) and glucose oxidase (HMEC-1) or lipopolysaccharide (LPS) in the presence of different fractions of mulberry EVs. Mulberry EVs augmented ROS production with DMNQ in THP-1 and caused the downregulation of ROS in HMEC-1. Mulberry EVs increased LPS-induced IL-1β secretion but reduced CCL2 and TGF-β secretion in THP-1 macrophages. In scratch wound assays, mulberry EVs inhibited HMEC-1 migration but increased proliferation in both low and high serum conditions, suggesting that they have opposing effects in these two important aspects of wound healing. One of the limitations of plant-derived therapeutics has been overcoming the low bioavailability of isolated compounds. We propose that PDVs could provide the link between physiological dose and therapeutic benefit by protecting plant active compounds in the GIT as well as potentially delivering genetic material or proteins that contribute to previously observed health benefits. [ABSTRACT FROM AUTHOR]

[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]

This paper presents the characterization and testing of electrochemical sensor using microfluidic system. Various geometric patterns were laser cut into the platinum working electrode of a biosensor. In this work, a microfluidic chamber was designed that allows phosphate buffer solution (PBS) to flow across the sensor, using a peristaltic pump, while varying the concentration of hydrogen peroxide. The amperometric characterization of the electrochemical sensor with 25, 50, 75, and 100 μ m perforation and 75 μ m spacing showed the highest sensitivity. This result was to be expected the purpose of patterning the sensors was to provide a 3-dimensional structure to the planar electrode in order for the enzyme, glucose oxidase, to be immobilized. Future work will include selecting one of the patterns for immobilization of glucose oxidase allowing us to realize a fully functional glucose sensor. [ABSTRACT FROM AUTHOR]

Scientific advances in biosensor technology are leading to the potential of wearable biosensors for salivary biomarker detection. This review aims to identify the current status of intraoral biosensor technology that can be used to monitor systemic diseases. A total of 11 studies were identified for inclusion, which included nine different devices, including modified mouthguards, retainers, toothbrushes, and dental floss. Out of the 11 studies, 8 studied continuous biomarker monitoring, and the remaining 3 were point-of-care applications. A total of seven biomarkers were studied, six of which investigated the intraoral detection of salivary glucose levels using glucose oxidase enzyme. All the sensors demonstrated excellent sensitivity (minimum R = 0.9928) and selectivity. The study designs were proof of concept, with five studies including in vivo components. We concluded that while there are established links between salivary biomarkers and systemic health, there is a lack of mature intraoral biosensor research. Refinement of biosensor design and data analysis is required to improve patient acceptability by promoting more discrete, real-time, low-cost, and wireless devices. Further research that utilises the biosensor technology in large controlled clinical trials will be required to confirm clinical applicability before intraoral biosensor technology can be integrated into routine health monitoring. [ABSTRACT FROM AUTHOR]

Nowadays, biosensors are gaining increasing interest in foods' and beverages' quality control, owing to their economic production, enhanced sensitivity, specificity, and faster analysis. In particular, colorimetric biosensors can be combined with color recognition applications on smartphones for the detection of analytes, rendering the whole procedure more applicable in everyday life. Herein, chitosan (CS) films were prepared with the deep eutectic solvent (DES) choline chloride/urea/glycerol (ChCl:U:Gly). Glucose oxidase (GOx), a widely utilized enzyme in quality control, was immobilized within CS films through glutaraldehyde (GA), leading to the formation of CS/GOx films. The optimized GOx concentration and DES content were determined for the films. Moreover, the effect of the pH and temperature of the glucose oxidation reaction on the enzymatic activity of GOx was studied. The structure, stability, and specificity of the CS/GOx films as well as the Km values of free and immobilized GOx were also determined. Finally, the analytical performance of the films was studied by using both a spectrophotometer and a color recognition application on a smartphone. The results demonstrated that the films were highly accurate, specific to glucose, and stable when stored at 4 °C for 4 weeks and when reused 10 times, without evident activity loss. Furthermore, the films displayed a good linear response range (0.1–0.8 mM) and a good limit of detection (LOD, 33 μM), thus being appropriate for the estimation of glucose concentration in real samples through a smartphone 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]

The study aims to address the need for accurate and real-time monitoring of glucose levels in college athletes during physical activities. This work reports on the development of an electrochemical sensor that uses glucose oxidase (GOx) immobilized on PdO nanoparticles to reduce graphene oxide (rGO) nanocomposite printed on a cellulose substrate (GO x /PdO-rGO/C-PE). The successful reduction of GO to rGO, the production of the PdO-rGO nanocomposite, and the electropolymerization of GOx on the PdO-rGO nanocomposite were all validated by the material characterization. The biosensor's electrochemical response investigation showed that its detection limit was 0.046 μM and its sensitivity was 0.03239 μA/μM. Excellent stability, reproducibility, and glucose selectivity were shown by the GOx/PdO-rGO/C-PE, which makes it a viable option for consistent and dependable glucose sensing in real-world applications. The real sample analysis assessed how well the combination of GOx/PdO-rGO/C-PE could identify glucose in human serum. Furthermore, under a variety of real-world conditions, such as during various physical activities and at different times of the day, the sensor demonstrated outstanding performance in real-time glucose monitoring. These findings imply that the GOx/PdO-rGO/C-PE offers accurate and dependable readings in the field of non-invasive glucose monitoring, which will be especially helpful for college and professional athletes. [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]

Honey is a natural sweetener made by bees that exhibits antimicrobial activity, mainly related to its H2O2 content. The aim of this work was to research the H2O2 concentration of 24 Spanish honeys from different botanical origins, studying their possible correlation with glucose oxidase (GOx), catalase (CAT), and anti-Staphylococcus aureus activities (minimal inhibition concentration (MIC), minimal bactericidal concentration (MBC), and percentage of inhibition at 5% (w/v) honey against Staphylococcus aureus), as well as possible correlations among all the analyzed parameters. The results showed that the H2O2 concentration did not depend on the botanical origin of the honeys. There were neither correlations between the H2O2 concentration and the activities of GOx and CAT, nor between GOx and antimicrobial activity. However, CAT and antimicrobial activities were positively correlated. Therefore, CAT could be successfully used as a possible marker of the antimicrobial activity of honeys against Staphylococcus aureus. Furthermore, a linear regression model has been fitted to explain the antimicrobial activity from CAT and GOx activity and H2O2 concentration. Although H2O2 is one of the compounds involved in honey's antibacterial activity, this capacity also strongly depends on other honey components (such as low water activity, acidity, osmolarity, and phenolic compounds). The very high anti-Staphylococcus aureus activity exhibited by all samples could be interesting for commercial honey-based formulations also helping to promote local beekeeping. [ABSTRACT FROM AUTHOR]

This document provides a summary of various research articles on the development of sensors and biosensors for different applications. The articles cover a range of topics, including the sensing of urea and creatinine, the detection of the CagA antigen in gastric cancer, the electrochemical sensing of methotrexate, the measurement of antibodies and antioxidant activity in saliva, the detection of genetic signatures of viruses, the investigation of the sensing properties of VSe2 monolayers, and the determination of ochratoxin A. The articles present different fabrication methods and techniques, as well as the optimization of detection limits and sensitivities. The research findings suggest the potential for these biosensors to be used in practical applications for monitoring health and detecting diseases. [Extracted from the article]

Real-time monitoring of physiological indicators inside the body is pivotal for contemporary diagnostics and treatments. Implantable electrodes can not only track specific biomarkers but also facilitate therapeutic interventions. By modifying biometric components, implantable electrodes enable in situ metabolite detection in living tissues, notably beneficial in invasive glucose monitoring, which effectively alleviates the self-blood-glucose-managing burden for patients. However, the development of implantable electrochemical electrodes, especially multi-channel sensing devices, still faces challenges: (1) The complexity of direct preparation hinders functionalized or multi-parameter sensing on a small scale. (2) The fine structure of individual electrodes results in low spatial resolution for sensor functionalization. (3) There is limited conductivity due to simple device structures and weakly conductive electrode materials (such as silicon or polymers). To address these challenges, we developed multiple-channel electrochemical microneedle electrode arrays (MCEMEAs) via a separated functionalization and assembly process. Two-dimensional microneedle (2dMN)-based and one-dimensional microneedle (1dMN)-based electrodes were prepared by laser patterning, which were then modified as sensing electrodes by electrochemical deposition and glucose oxidase decoration to achieve separated functionalization and reduce mutual interference. The electrodes were then assembled into 2dMN- and 1dMN-based multi-channel electrochemical arrays (MCEAs), respectively, to avoid damaging functionalized coatings. In vitro and in vivo results demonstrated that the as-prepared MCEAs exhibit excellent transdermal capability, detection sensitivity, selectivity, and reproducibility, which was capable of real-time, in situ glucose concentration monitoring. [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]

Oxidative stress from excess H2O2 activates transcription factors that restore redox balance and repair oxidative damage. Although many transcription factors are activated by H2O2, it is unclear whether they are activated at the same H2O2 concentration, or time. Dose-dependent activation is likely as oxidative stress is not a singular state and exhibits dose-dependent outcomes including cell-cycle arrest and cell death. Here, we show that transcription factor activation is both dose-dependent and coordinated over time. Low levels of H2O2 activate p53, NRF2 and JUN. Yet under high H2O2, these transcription factors are repressed, and FOXO1, NF-κB, and NFAT1 are activated. Time-lapse imaging revealed that the order in which these two groups of transcription factors are activated depends on whether H2O2 is administered acutely by bolus addition, or continuously through the glucose oxidase enzyme. Finally, we provide evidence that 2-Cys peroxiredoxins control which group of transcription factors are activated. H2O2 stress is known to activate a slew of transcription factors that restore redox balance. Here, the authors use live-cell imaging and single-cell analysis to reveal that the transcription factors that are activated and their timing of activation is dose dependent. [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]

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]

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]

This work aims to develop new H2O2-sensing elements and nanozyme-oxidase-based sensors for the detection of hydrogen peroxide, glucose, and galactose. Methods. Chemical synthesis. Assay of enzymatic activity. Scanning electron microscope. Results. Hexacyanoferrates of several transient metals were synthesized and tested for their nanozymes (HCF NZs) (certificial peroxidase) activity in solution. The best representative nanozymes (NZs) were used for the construction of H2O2-sensitive sensors and nanozyme-oxidase-based biosensors. The NZs-based sensors: nAuHCF/GE and nPtHCF/GE demonstrated higher sensitivity (7.5 and 9.4-fold) than the biosensor with natural peroxidase. The developed biosensors GOX/nPtHCF/GE and GaOx/nPtHCF/GE for the detection of glucose and galactose showed enhanced sensitivity: 900 and 540 A·M-1·m-2, respectively, broad linear range (0.02-0.2 mM). Along with a broad linear range of detection these biosensors possess low limits of detection -- 4.0 μM for glucose and 6.0 μM for galactose. Additionally, these biosensors exhibited improved stability when compared to the control. Conclusions. The novelty of the presented work is related to the synthesis of new peroxidase-like NZs and the evaluation of their functionality as the chemosensors on H2O2 and as the sensing components in the oxidase-based-biosensors for assay of glucose and galactose. The nPtHCF and nAuHCF NZs exhibit high sensitivity for the target analytes, a broad linear range, and satisfactory storage stability. The main advantages of the proposed nanozyme-oxidase-based biosensors are the simple architecture of the sensing layer and the ability to operate at low working electrode potentials. [ABSTRACT FROM AUTHOR]