Glucose Oxidase Catalysis Research Articles

A novel and sensitive microneedle array platform for visual detection of glucose based on Zr-MOF@Pt nanozyme with peroxidase-like activity

The level of glucose, one of the body’s energy-providing substances, is closely related to many diseases. Therefore, it remains a challenge to develop platform that can satisfy both the need for accurate detection of glucose for clinical diagnosis as well as device-free and efficient on-site monitoring of blood glucose. Herein, we synthesized Zr-MOFs@Pt nanocomposites for the first time. The peroxidase-like activity of Zr-MOFs@Pt was greatly enhanced two times compared with Zr-MOFs, due to the synergistic effect of Pt nanoparticles that was in situ growing in Zr-MOFs. Hydrogen peroxide was generated from glucose with the catalysis of glucose oxidase (GOx). H2O2 was decomposed by Zr-MOFs@Pt to produce free radical, which could oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) to generate blue oxTMB, and could be utilized for colorimetric sensing of glucose. By crosslinking, TMB and PVA hydrogel matrix formed the microneedle patch display layer, and PVA as well as GOx composed the tip of the needle, the sensing system was developed to hydrogel microneedles array for detection of glucose. When the tip of the needle was inserted into a solution containing glucose, it reacted with GOx in the tip sector to produce H2O2. The H2O2 would react with Zr-MOFs@Pt in the display layer to produce free radicals, and further oxidize TMB causing the display layer to exhibit blue color. This work provides a new approach for designing device-free sensing platforms for glucose monitoring, which also offers great potential for development of microneedle analytical devices.

Determination of glucose oxidase activity by tyrosine fluorescence spectrophotometry

A novel Fe2+/Tyr/H2O2 fluorescence reaction system has been established for the purpose of analyzing glucose oxidase activity. This system involves the catalysis of glucose oxidase on glucose to produce H2O2, which in turn oxidizes tyrosine to a highly fluorescent substance under the catalysis of Fe2+. The fluorescence intensity is subsequently employed to ascertain the enzymatic activity of glucose oxidase. The enzymatic oxidation reaction and tyrosine fluorescence reaction conditions were optimized based on the H2O2 standard curve equation. Direct fluorescence spectrophotometry was used to determine the activity range and detection limit of glucose oxidase, which were found to be 7.00 × 10−5–7.00 × 10−2 U/mL and 3.36 × 10−5 U/mL (Enzyme-like activity is 6.72 × 10−4 U/mL, The enzyme reaction time is 5 min), respectively, with a relative standard deviation of less than 3.2 %. This method has been successfully applied to determine the activity of glucose oxidase in food additives, with a recovery rate ranging from 96.00 % to 102.0 %.

A multimodal therapy for infected diabetic wounds based on glucose-responsive nanocomposite-integrated microneedles.

Diabetic wounds in a state of high glucose are refractory to treatment and healing, especially if they are infected with bacteria. Herein, a novel nanocomposite (CIP/GOx@ZIF-8) was synthesized by loading ciprofloxacin hydrochloride (CIP) and glucose oxidase (GOx) into zeolitic imidazole framework-8 (ZIF-8) that exhibited good glucose sensitivity and catalytic activity. The high glucose in diabetic wounds could be decomposed into hydrogen peroxide (H2O2) and gluconic acid via the catalysis of GOx, which further destroyed CIP/GOx@ZIF-8 to release Zn2+ and cargos. The combination of glucose starvation, Zn2+, H2O2 and CIP could elevate the antibacterial effect and reduce bacterial resistance. Subsequently, the nanocomposite was fabricated into dissolving microneedles (CIP/GOx@ZIF-8 MNs) using polyvinylpyrrolidone (PVP). The microneedles exhibited good mechanical strength, puncture performance, dissolving performance, glucose responsiveness, antibacterial performance and biocompatibility. For in vivo wound healing, CIP/GOx@ZIF-8 MNs with good biosafety facilitated neovascularization and collagen deposition as well as reduced inflammation, and the wounds were almost healed after treatment. This multimodal therapeutic strategy is created to provide a unique treatment for infected diabetic wounds.

Two-pronged microenvironmental modulation of metal-oxidase cascade catalysis and metabolic intervention for synergistic tumor immunotherapy

Immunotherapy is an emerging treatment modality for tumors after surgery, radiotherapy, and chemotherapy. Despite the potential for eliminating primary tumor cells and depressing cancer metastasis, immunotherapy has huge challenges including low tumor immunogenicity and undesirable immunosuppressive tumor microenvironment (TME). Herein, the two-pronged microenvironmental modulation nanoplatform is developed to overcome these limitations. Specifically, hollow mesoporous MnO2 (HM) nanoparticles with pH responsive property are prepared and modified with glucose oxidase (GOX) by amide bond, which are further loaded with a potent glutaminase inhibitor CB839 to obtain HM-GOX/CB839. Under the low pH values in TME, HM was disintegrated, thereby releasing Mn2+, GOX and CB839. On the one hand, Mn2+ can convert H2O2 that increased by GOX catalysis in tumors into highly toxic hydroxyl radicals (•OH) and further induce immunogenic cell death (ICD) through the metal-oxidase cascade catalytic reaction, enhancing immunogenicity. On the other hand, GOX and CB839 can block glycolytic and glutamine metabolism pathways, respectively, which effectively reduce the number of immunosuppressive cells and reshape TME, improving anti-tumor immune efficacy. It is demonstrated that HM-GOX/CB839 can effectively activate the body's immunity and inhibit tumor growth and metastasis, providing a potential strategy for comprehensive tumor therapy. Statement of significanceIntegrated microenvironmental modulation of metal-oxidase cascade catalysis and metabolic intervention offers a potential avenue for tumor immunotherapy. Under this premise, we constructed a two-pronged microenvironmental modulation nanoplatform (HM-GOX/CB839). On the one hand, the metal oxidase cascade could catalyze the generation of hydroxyl radicals (•OH) and induce immunogenic cell death (ICD), enhancing immunogenicity; on the other hand, metabolic intervention reprogrammed tumor microenvironment to relieve immunosuppression and thereby enhancing anti-tumor immune response. The resulting data demonstrated that HM-GOX/CB839 effectively inhibited tumor growth and metastasis, providing therapeutic potential for cancer immunotherapy.

Comprehensively Optimizing Fenton Reaction Factors for Antitumor Chemodynamic Therapy by Charge-Reversal Theranostics.

Chemodynamic therapy (CDT) is a highly tumor-specific treatment, while its efficacy is compromised by the intratumoral Fenton reaction efficiency, which is determined by the following reaction factors, including the availability of Fenton ions (e.g., Fe2+), the amount of H2O2, and the degree of acidity. Synchronous optimization of these factors is a big challenge for efficient CDT. Herein, a strategy of comprehensively optimizing Fenton reaction factors was developed for traceable multistage augmented CDT by charge-reversal theranostics. The customized pH-responsive poly(ethylene)glycol-poly(β-amino esters) (PEG-PAE) micelle (PM) was prepared as the carrier. Glucose oxidase (GOx), Fe2+, and pH-responsive second near-infrared (NIR-II) LET-1052 probe were coloaded by PM to obtain the final theranostics. The activity of metastable Fe2+ remained by the unsaturated coordination with PEG-PAE. Then tumor accumulation and exposure of Fe2+ were achieved by charge-reversal cationization of PEG-PAE, which was further enhanced by a GOx catalysis-triggered pH decrease. Together with the abundant H2O2 generation and pH decrease through GOx catalysis, the limiting factors of the Fenton reaction were comprehensively optimized, achieving the enhanced CDT both in vitro and in vivo. These findings provide a strategy for comprehensively optimizing intratumoral Fenton reaction factors to overcome the intrinsic drawbacks of current CDT.

Electrospun fibers integrating enzyme-functionalized metal-organic frameworks for postoperative tumor recurrence inhibition and simultaneously wound tissue healing

The tumor recurrence and infected wound tissue defect are the major clinical challenges after the surgical treatment of primary chest wall cancer. Herein, to address the above issues, blending electrospinning was applied to incorporate glucose oxidase (GOx) loaded Zn/Cu-based bimetallic zeolitic imidazolate frameworks (GOx/BMOFs) into polyurethane (PU) fibers, which were designed for effective cancer therapy with improved wound healing. The release of Cu2+ and GOx could accomplish the conversion from Cu2+ to Cu+ through the glutathione (GSH) depletion and provide additional H2O2 from glucose by GOx catalysis, respectively, which further underwent the Fenton-like reaction to produce toxic hydroxyl radical (OH). The tumor cells (human fibrosarcoma cells) could be effectively killed in vitro and in vivo through the synergistic chemodynamic therapy and starvation therapy. Moreover, the electrospun fiber platform could support the adhesion and proliferation of wound tissue cells, and also show the antibacterial ability owing to the functional agents in the fibers, thereby accelerating the infected wound repair in vivo. This work may offer a reliable and effective fiber biomaterial for localized chest wall tumor therapy and simultaneous tissue regeneration.

Carbon Dot-Modified Branched TiO2 Photoelectrochemical Glucose Sensors with Visible Light Response.

The development of a photoelectrochemical (PEC) sensor for the sensitive and rapid detection of glucose is highly desirable. In PEC enzyme sensors, inhibition of the charge recombination of electrode materials is an efficient technique, and detection in visible light can prevent enzyme inactivation due to ultraviolet irradiation. In this study, a visible light-driven PEC enzyme biosensor was proposed, using CDs/branched TiO2 (B-TiO2) as the photoactive material and glucose oxidase (GOx) as the identification element. The CDs/B-TiO2 composites were produced via a facile hydrothermal method. Carbon dots (CDs) can not only act as photosensitizers but also inhibit photogenerated electron and hole recombination of B-TiO2. Under visible light, electrons in the carbon dots flowed to B-TiO2 and further to the counter electrode through the external circuit. In the presence of glucose and dissolved oxygen, H2O2 generated through the catalysis of GOx could consume electrons in B-TiO2, causing a decrease in photocurrent intensity. Ascorbic acid was added to ensure the stability of the CDs during the test. Based on the variation of the photocurrent response, the CDs/B-TiO2/GOx biosensor presented a good sensing performance of glucose in visible light, its detection range was from 0 to 9.00 mM, and the detection limit was 0.0430 mM.

A Glucose Metabolic Intervention Nanoplatform for Enhanced Chemodynamic Therapy and Sensitized Photothermal Therapy of Hepatocellular Carcinoma

Traditional treatments for hepatocellular carcinoma (HCC) still lack effectiveness. Recently, the combined mode of chemodynamic therapy (CDT) and photothermal therapy (PTT) has shown great potential against HCC. However, insufficient Fenton reaction rates and hyperthermia-induced heat shock responses greatly impair their efficiency, hindering their further clinical application. Here, we constructed a cascade-amplified PTT/CDT nanoplatform by coating an IR780-embedded red blood cell membrane on glucose oxidase (GOx)-loaded Fe3O4 nanoparticles for effective HCC treatment. On the one hand, the nanoplatform interfered with glucose metabolism through the action of GOx to reduce the synthesis of ATP, which reduced the expression of heat shock proteins, thereby sensitizing the IR780-mediated PTT. On the other hand, hydrogen peroxide generated during GOx catalysis and the thermal effect of PTT accelerated the Fe3O4-mediated Fenton reaction, realizing enhanced CDT. Consequently, the sensitized PTT and enhanced CDT for HCC management could be simultaneously achieved by interfering with glucose metabolism, providing an alternative strategy for the effective treatment of tumors.

Horseradish peroxidase (HRP) and glucose oxidase (GOX) based dual-enzyme system: Sustainable release of H2O2 and its effect on the desirable ping pong bibi degradation mechanism

In this study, an adaptable HRP/GOX-Glu system was established due to the trait, efficient degradation of pollutants in the catalytic process of HRP named the ping-pong bibi mechanism and a sustained release of H2O2 in-situ under the catalysis of glucose oxidase (GOX). Compared with the traditional HRP/H2O2 system, the HRP was more stable in the HRP/GOX-Glu system based on the feature of persistent releasing H2O2 in-situ. Simultaneously, the high valent iron was found out to give a greater contribution to Alizarin Green (AG) removal through ping-pong mechanism, whereas the hydroxyl radical and superoxide free radical generated by Bio-Fenton were also the main active substances for AG degradation. Furthermore, on the basis of effect evaluation of the co-existence of two different degradation mechanisms in the HRP/GOX-Glu system, the degradation pathways of AG were proposed. Moreover, the optimum reaction conditions preferentially triggering ping-pong bibi mechanism instead of Bio-Fenton were determined by single factor analysis and degradation mechanism elaboration. This study would provide a reference for how to give full play to the advantages of ping-pong bibi mechanism in the dual-enzyme system based on HRP to degrade pollutants with high efficiency.

Zeolitic imidazolate framework-8 encapsulating carbon nanodots and silver nanoparticles for fluorescent detection of H2O2 and glucose

In this study, a novel fluorescent biosensor is developed for the detection of H2O2 and glucose based on Zeolitic Imidazolate Framework-8 (ZIF-8) nanocomposites. ZIF-8 encapsulating carbon nanodot (CD) exhibits bright fluorescence emission. After further loading of AgNP, the fluorescence is quenched, which is mainly based on the excited electron transfer from CD to AgNP. Besides, the excitation wavelength of CD falls within the adsorption range of AgNP, which leads to efficient inhibition of the excitation energy. The as-prepared AgNP-CD-ZIF-8 nanocomposites can be utilized as a highly sensitive platform for the analysis of H2O2 and glucose. In the presence of glucose, H2O2 can be generated by the catalysis of glucose oxidase (GOD), which induces the etching of AgNP and subsequent recovery of CD-ZIF-8 fluorescence. This “turn on” biosensor can be applied for facile and convenient quantification of H2O2. It can also be further extended to detect glucose in real samples after combining specific catalytic effect of GOD. The analytical performances are excellent, which demonstrates great potential for practical utility.

Biomimetic Enzyme Cascade Structural Color Hydrogel Microparticles for Diabetic Wound Healing Management

Hard-healing diabetic wound brings burgeoning physical and mental burdens to patients. Current treatment strategies tend to achieve multistage promotion and real-time reporting to facilitate wound management. Herein, a biomimetic enzyme cascade inverse opal microparticles system for wound healing, which is intergated with glucose oxidase (GOD) and copper peroxide (CP). Such microparticles are composed of biofriendly hyaluronic acid methacryloyl (HAMA) and pH-responsive acrylic acid (AA), which provided abundant binding sites and spaces for chemical immobilizing and physical doping of enzymes and metal bioinorganics. When the cascade catalytic system is applied on wound sites, hyperglycemia environment would serve as a hydrogen peroxide (H2 O2 ) generator through GOD catalysis, while acidic environment triggers the decomposition of CP, further catalyzing H2 O2 to generate reactive oxygen species (ROS). Additionally, the distinctive structural color of the microparticles can visually reflect the wound pH and intelligently estimate the healing state. It is demonstrated that such microparticle systems exhibit excellent broad-spectrum antibacterial and angiogenesis-promoting properties, as well as significant real-time reporting ability for wound healing. These features indicate that enzyme cascade structural color microparticles possess valuable potential in wound healing and related field.

A Versatile Nanoplatform Based on Metal‐Phenolic Networks Inhibiting Tumor Growth and Metastasis by Combined Starvation/Chemodynamic/Immunotherapy

AbstractAlthough much progress has been made by multifunctional nanoplatforms in the treatment of cancer, several defects of existing nanoplatforms, such as tedious preparation, poor biocompatibility, and failure to activate the immune system, have limited their clinical applications. Herein, a versatile nanosystem of folic acid‐modified metal‐phenolic networks (MPNs) loaded with GOx and CHA (F‐MGC) is fabricated by the easy self‐assembly of MPNs, during which glucose oxidase (GOx) and chlorogenic acid (CHA) are concurrently loaded. The resulting nanosystem, having a folic acid‐modified surface and inherent acid sensitivity, shows versatility in being able to target tumors and release active ingredients in the weakly acidic tumor microenvironment (TME). Based on the catalysis of GOx and Fe3+, the cascade reaction aroused by F‐MGC efficiently consumes glucose in the TME and produces abundant cytotoxic hydroxyl radicals, thereby causing the starving and chemodynamic death of cancer cells. In addition, CHA can reshape M2 tumor‐associated macrophages (TAMs) into the M1 type, so as to change the immunosuppressive state of TME. The immunogenic cell death (ICD) that occurs from the starvation and chemodynamic therapy, in conjunction with the CHA‐induced TAMs polarization, further activates the immune system. Overall, the easily prepared nanoplatform has excellent biocompatibility and effectively inhibits tumor growth and metastasis.

Diabetes immunity-modulated multifunctional hydrogel with cascade enzyme catalytic activity for bacterial wound treatment

Diabetes immunity-modulated wound treatment in response to the varied microenvironments at different stages remains an urgent challenge. Herein, glucose oxidase (GOx) and quasi-amorphous Fe2O3 are co-incorporated into Zn-MOF nanoparticle (F-GZ) for cascade enzyme catalytic activities, where not only the high blood glucose in the wound is consumed via the GOx catalysis, but also the effective anti-bacteria is achieved via the degradedly released Zn2+ synergistically with the catalytically produced ·OH during the bacterial infection period with the low pH microenvironment. Simultaneously, the reactive oxygen species scavenging and hypoxia relief is realized via catalyzing H2O2 to produce O2 at the relatively elevated pH environment during the wound recovery period. Subsequently, a multifunctional hydrogel with injectable, self-healing and hemostasis abilities, as well as uniformed F-GZ loading is prepared via the copolymerization reaction. This hydrogel behaves as F-GZ but reduces the toxic effects, which thus accelerates the diabetic wound healing. More importantly, this hydrogel is found to modulate the diabetes immunity possibly mediated via the released Zn2+, which thus contributes to the recovered pancreatic islet functions with improved glucose tolerance and increased insulin secretion for enhanced diabetic wound treatments. This work initiates a new strategy for simultaneous diabetic wound management and also suggests a potential way for diabetic immunity modulation.

Nanozyme-based sensitive ratiometric fluorescence detection platform for glucose

Development and application of carbon-based nanozymes are attracting wide interest in recent years. Abnormal glucose level can be threat to human health. Sensitive and accurate sensing methods for glucose are still of great urgency. In this work, we constructed a sensitive nanozyme-based ratiometric fluorescence sensing platform for glucose. The sensing system composed of copper-doped carbon-based nanozyme (CuAA) with superb peroxidase-like activity and Mg/N doped carbon quantum dots (Mg–N-CQDs) with distinguished fluorescence property. Efficient tandem catalysis of glucose oxidase (Glu Ox) and CuAA, and inner-filter effect (IFE) between 2, 3-diaminophenazine (DAP) and Mg–N-CQDs played crucial roles in this sensing system. The oxidization of glucose was catalyzed by Glu Ox firstly to produce H2O2. In the presence of H2O2, fluorescent DAP was formed from non-fluorescent substrate o-phenylenediamine (OPD) with assistance of CuAA, resulting in generation of emission at 558 nm. Meanwhile, the emission at 444 nm from Mg–N-CQDs was quenched efficiently by DAP through IFE. The ratiometric fluorescence signal I558/I444 increased linearly with glucose concentration in the scope of 2–400 μmol L−1, the limit of detection (LOD) was 1.56 μmol L−1. It was also practicable to apply the method to the determination of glucose in human serum, satisfactory recoveries and RSDs were acquired.

Nano-channel confined biomimetic nanozyme/bioenzyme cascade reaction for long-lasting and intensive chemiluminescence

We present here a novel nano-channel confined biomimetic nanozyme/bioenzyme system, which is prepared by co-immobilizing polyoxometalates (vanadomolybdophosphoric heteropoly acid, PMoV2) and glucose oxidase (GOx) in the nano-scale channel of core-shell mesoporous silica (CSMS) microspheres. The biomimetic dual-enzyme nanoreactors (CSMS@PMoV2@GOx) is used for producing long-lasting chemiluminescence (CL) emission. With glucose and luminol in the reaction mixture, hydrogen peroxide (H2O2) is formed in mesoporous channels by GOx catalysis and then is consumed immediately by PMoV2 to induce CL emission. Confined in nano-size channels of CSMS materials, the biomimetic cascade reactions can induce a long-lasting CL emission with a flat period over 12 h. The proposed CSMS@PMoV2@GOx system has excellent reproducibility and storage stability, and has been applied for glucose sensing in human serum samples with satisfactory accuracy. Our study provides a new glow-type CL system based on nanozyme/bioenzyme cascade reactions confined in nano-scale channels of CSMS microspheres, and will also shed a light on potential application of functional polyoxometalates immobilized in mesoporous materials, which would be of great value in various fields including bioassays and heterogeneous catalysis.

Multifunctional liquid metal-based nanoparticles with glycolysis and mitochondrial metabolism inhibition for tumor photothermal therapy

Tumor cells obtain energy supply from different metabolic pathways to maintain survival. In this study, a tumor acidity-responsive spherical nanoparticle (called as LMGC) was designed by attaching glucose oxidase (GOx) and mineralizing calcium carbonate on the surface of liquid metal nanoparticles to integrate the synergistic effect of adenosine triphosphate (ATP) generation inhibition and photothermal therapy (PTT) for enhanced tumor therapy. After GOx catalysis, the process of glycolysis was inhibited, and the increased H2O2 level enhanced the intratumoral oxidative stress. Besides, the gluconic acid production accelerated the degradation of LMGC and promoted Ca2+-mediated mitochondrial dysfunction. The inhibition of glycolysis and mitochondrial metabolism could significantly reduce ATP production and down-regulate heat shock protein (HSP) expression, which would reduce tumor cells heat resistance and improve PTT therapeutic effect. This liquid metal-based ATP inhibition system with enhanced therapeutic effect will find great potential for tumor treatment.

Green rust (GR) and glucose oxidase (GOX) based Fenton-like reaction: Capacity of sustainable release, promoted conversion of glucose through GOX-iron and pH self-adjustment

The Fenton reaction is regarded as highly efficient for the degradation of organic contaminants. However, the traditional Fenton reaction is still flawed in a narrow pH working range and low utilization efficiency of the reagents. Based on two striking features, a sustained release of H2O2 in-situ under the catalysis of glucose oxidase (GOX) and the rapid electron donation & transferability from green rust (GR), an adaptable biological Fenton-like system (GGGMFs) was established. The coupling roles of glucose, GOX and GR in the degradation of 3,4-dimethylaniline (3,4-DMA) and the types of reactive species were deduced by electron spin resonance (ESR), etc.. Results demonstrated that the suitable pH range of the system was optimized from acidic to circumneutral, which was favorable for practical application, owing to the heterogeneous formation of GR and the pH self-adjustable capacity of GOX-Glucose. Meanwhile, hydroxyl radical (·OH), superoxide radical (·O2−) and Fe (IV) were identified to be the main oxidizing reactive species. Taking different selectivity of the reactive species to certain pollutant functional groups into consideration, the degradation pathways of 3,4-DMA were proposed. Moreover, it was shown that GR not only acted as the activating substance of the Fenton-like reaction, but also enhanced the activity of GOX, resulting in the promotion of glucose conversion in GGGMFs. This study shed light on the enhancement mechanism consisting of two aspects: (i) the elimination of product inhibition (ii) the formation of a 2Fe(III)-FAD complex with FAD, the active center of GOX, which prompted the electronic transfer in the enzyme catalytic reaction.

Multivesicular Liposomes for Glucose-Responsive Insulin Delivery.

An intelligent insulin delivery system is highly desirable for diabetes management. Herein, we developed a novel glucose-responsive multivesicular liposome (MVL) for self-regulated insulin delivery using the double emulsion method. Glucose-responsive MVLs could effectively regulate insulin release in response to fluctuating glucose concentrations in vitro. Notably, in situ released glucose oxidase catalyzed glucose enrichment on the MVL surface, based on the combination of (3-fluoro-4-((octyloxy)carbonyl)phenyl)boronic acid and glucose. The outer MVL membrane was destroyed when triggered by the local acidic and H2O2-enriched microenvironment induced by glucose oxidase catalysis in situ, followed by the further release of entrapped insulin. Moreover, the Alizarin red probe and molecular docking were used to clarify the glucose-responsive mechanism of MVLs. Utilizing chemically induced type 1 diabetic rats, we demonstrated that the glucose-responsive MVLs could effectively regulate blood glucose levels within a normal range. Our findings suggest that glucose-responsive MVLs with good biocompatibility may have promising applications in diabetes treatment.

A multifunctional nanoamplifier with self-enhanced acidity and hypoxia relief for combined photothermal/photodynamic/starvation therapy

Phototherapies, including photothermal therapy (PTT) and photodynamic therapy (PDT) have been potential noninvasive therapeutic modality with high efficiency, however, there still exist some intrinsic limitations that impede their clinical applications. Herein, taking the advantages of the synergistic effect and high reactivity of manganese dioxide (MnO2) nanosheets and glucose oxidase (GOx), multifunctional MPDA@MnO2-MB-GOx nanoamplifier was constructed for enhanced PTT, PDT, and starvation therapy. In tumor microenvironment (TME), MnO2 nanosheets on the surface of mesoporous polydopamine (MPDA) could react with endogenous hydrogen peroxide (H2O2) and generate oxygen (O2) to relieve tumor hypoxia, thus enhancing the efficacy of PDT and GOx catalysis. Glucose consumption under the catalysis of GOx will enhance the acidity of TME and increase intracellular H2O2 concentration, which in turn promotes the production of O2 by MnO2 nanosheets, thus forming efficient cascade reaction and maximizing the efficacy of the functional agents. Furthermore, the heat generated by MPDA under the irradiation of 808 nm laser can accelerate chemical reactions, thus further enhancing synergistic therapeutic efficacy. In vitro/vivo results emphasize that enhanced cancer cell death and tumor inhibition are gained by modulating unfavorable TME with the functional nanosystem, which highlights the promise of the synthesized MPDA@MnO2-MB-GOx nanomaterial to overcome the limitations of phototherapy.

Ionic liquids impact on the catalysis of glucose oxidase and Cu/luminol/H2O2 system

Ionic liquids impact on the catalysis of glucose oxidase and Cu/luminol/H2O2 system