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1.
Biosens Bioelectron ; 195: 113586, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34455144

RESUMO

Enzyme-based biosensors are sensitive to temperature due to their strong temperature dependency of catalytic activity. Aiming at enhancing biosensing detection for glucose assay over a wide range of applicable temperatures, we designed a thermal self-regulatory intelligent biosensor through an innovative integration of phase change material (PCM) and bioelectrocatalytic substances. An electroactive phase-change microcapsule system was firstly fabricated by microencapsulating n-docosane as a PCM core in the SiO2 shell, followed by depositing polydopamine along with carbon nanotubes as an electroactive layer on the surface of SiO2 shell. The resultant microcapsules showed a regularly spherical morphology and well-defined core-shell microstructure. They also exhibited a satisfactory latent heat capacity of around 137 J/g for implementing temperature regulation with a good working stability. An electrochemical biosensing system was constructed with the resultant electroactive microcapsules together with glucose oxidase as a redox enzyme, achieving a thermal self-regulation capability to enhance the biosensing detection of glucose under in-situ thermal management at higher temperatures. With a high sensitivity of 5.95 µA⋅mM-1⋅cm-2 and a lower detection limit of 13.11 µM at 60 °C, the intelligent biosensor developed by this study demonstrated a superior determination capability and better detection performance toward glucose than conventional biosensors in a high temperature region thanks to effective regulation of microenvironment temperature in the electrode system. This study provides a promising strategy for the development of thermal self-regulatory smart biosensors with an enhanced identification ability to detect various chemical substances over a wide range of applicable temperatures.


Assuntos
Técnicas Biossensoriais , Nanotubos de Carbono , Cápsulas , Eletrodos , Enzimas Imobilizadas , Glucose , Glucose Oxidase , Dióxido de Silício
2.
Food Chem ; 366: 130591, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34293548

RESUMO

For the shelf life extension of fruits, we envisioned a novel antimicrobial approach that is based on the production of a thin layer of hydrogen peroxide at the surface of food by utilizing the bioactivity of glucose oxidase (GOx). The enzyme, purified from Aspergillus Niger, was immobilized on zinc oxide nanoparticles and then suspended in a buffer to prepare a spraying solution of GOx/ZnONPs. Post-immobilization analyses indicated that immobilized enzyme showed higher activity as compared to the free enzyme. The GOx/ZnONPs spray was applied for postharvest treatment of peach. The control and treatment groups were stored at ambient conditions for fifteen days and standard quality parameters were analyzed. In contrast to the control group, the GOx/ZnONPs spray treatment was remarkably effective in maintaining the physiological appearance of fruits even more than 12 days and showed a significant reduction in the decrease of weight, firmness, TSS, and DPPH free radical scavenging activity of fruits. Thus GOx/ZnONPs is an excellent platform to extend the postharvest shelf life of peach.


Assuntos
Nanopartículas , Prunus persica , Óxido de Zinco , Enzimas Imobilizadas , Frutas , Glucose Oxidase
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 265: 120376, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34571376

RESUMO

Metal-organic framework (MOF) MOF-Fe nanosols were prepared, which exhibits strongly catalysis of the new fluorescence indicator reaction of 3, 3', 5, 5'-tetramethylbenzidine (TMB)-H2O2 to produce the oxidation product TMBOX. The TMBOX fluorescent probe has a strong fluorescence peak at 405 nm. After optimizing the various conditions for the determination of H2O2 system and glucose system, the linear range of fluorescence determination of H2O2 was 0.75-7.5 µM, and the detection limit was 0.3 µM. Since H2O2 is the product of glucose oxidase (GOD) catalyzed oxidation of glucose, and a simple and convenient fluorescence method was also established for glucose. The results show that the glucose concentration in the range of 0.2-20 µM has a good correlation with the fluorescence intensity, and the detection limit of glucose was 0.1 µM. This method has been used to detect the content of glucose in drinks with satisfactory results.


Assuntos
Peróxido de Hidrogênio , Estruturas Metalorgânicas , Catálise , Colorimetria , Glucose , Glucose Oxidase/metabolismo , Limite de Detecção , Oxirredução
4.
Food Chem ; 371: 131166, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34583178

RESUMO

Melon juice produces strong cooked off-odors during heat processing, leading to serious deterioration of aroma quality. In this work, the aroma quality of melon juice, the changes in GOD reaction products, and the interactions of reaction products and cooked off-odor components were analyzed by sensory evaluation, gas chromatography-mass spectrometry/olfactory, ultraperformance liquid chromatography-triple quadrupole mass spectrometry, and isothermal titration calorimetry to study the effect mechanism of glucose oxidase (GOD) on the release of cooked off-odor components from heat-treated melon juice. The results showed that GOD treatment improved the aroma quality mainly by controlling off-odor attributes and maintaining characteristic odor attributes. This was because the reaction products (hydrogen peroxide and gluconic acid) of GOD treatment inhibited the release of cooked off-odor components from heat-treated melon juice through oxidation and hydrophobic effects. Furthermore, these products reduced the loss of characteristic odor compounds by restraining Maillard, degradation, and oxidation reactions during heat processing.


Assuntos
Cucurbitaceae , Compostos Orgânicos Voláteis , Cromatografia Gasosa-Espectrometria de Massas , Glucose Oxidase , Temperatura Alta , Odorantes/análise , Compostos Orgânicos Voláteis/análise
5.
Food Chem ; 370: 130901, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34500289

RESUMO

The development of Aspergillus niger (A. niger) spores as glucose oxidase (GOD) biocatalysts to produce gluconic acid is highly anticipated in the food industry. Herein, a piezoelectric sensor (PIS) method has been developed for the detection of GOD activity and better application of rapid screening of GOD activity in A. niger spores. The GOD activity detection is based on GOD catalyzing ß-d-glucose to produce gluconic acid, which results in frequency shift changes recorded by the PIS device in real-time. Using the PIS method, the kinetic parameter 6.5 mg/mL, the correlation equation υ0=31.92CGOD+1.04, the recoveries (89.4%-93.9%, and their RSDs were all within 6.1%) and the optimal GOD activity in A. niger spores under different treatment conditions was obtained. Compared with the classical methods, the proposed method is accurate, rapid, convenient and does not require additional reagents. It has a broad range of potential applications for exploring new GOD biocatalysts.


Assuntos
Aspergillus niger , Glucose Oxidase , Glucose , Esporos Fúngicos
6.
Anal Chem ; 93(45): 14934-14939, 2021 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-34723511

RESUMO

The mesh-type USB piezoelectric ultrasonic transducer (USB-PUT) used in household humidifiers and inhalation therapy devices is very cheap, small, and energy saving. It holds great promise for sonochemistry. However, the microtapered apertures in the center of the stainless steel substrate of mesh-type USB-PUT can lead to rapid atomization of solution, leakage of solutions containing surfactants and organic solvent through the apertures, and high background emission. Herein, we design a new type of USB-PUT by replacing the meshed stainless steel substrate with an apertureless stainless steel substrate. We have found that this apertureless USB-PUT can not only induce intense sonochemiluminescence (SCL) but can also enable sensitive luminol SCL detection of hydrogen peroxide which is practically impossible using mesh-type PUT because of the strong background SCL emission. By using this apertureless device to induce SCL and using smart phone as a detector, a visual hydrogen peroxide SCL detection method with a linear range of 0.5-50 µM and a detection limit of 0.32 µM is established. Moreover, the device can achieve the detection of glucose oxidase (GOD) activity and glucose by enzymatic conversion of glucose to hydrogen peroxide. The linear range of GOD detection is 1-200U/L with a detection limit of 0.86 U/L. The linear range of glucose detection is 0.5-70 µM with a detection limit of 0.43 µM. The cheap (a few dollars) and user-friendly apertureless USB-PUT is promising for sonochemistry applications and chemical education.


Assuntos
Técnicas Biossensoriais , Peróxido de Hidrogênio , Glucose , Glucose Oxidase , Limite de Detecção , Transdutores , Ultrassom
7.
Anal Chem ; 93(43): 14521-14526, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34666486

RESUMO

The chemical reaction in a confined space is known to be accelerated due to a high collision probability; however, the study of this confinement effect in a supersmall space down to femtoliter (fL) is seldom reported. Here, an adjustable volume [from picoliter (pL) to fL] of the aqueous phase is retrained at the tip of a nanopipette by an organic solvent so that the confinement effect on the specific activity of glucose oxidase is investigated. The activity is determined by the amount of hydrogen peroxide generated from the reaction between the oxidase and glucose using a nanoelectrode inside the nanopipette. As compared with the activity in bulk solution (82 U/mg), the activity increases up to 7500 U/mg in a 105 fL space. The 2 orders of magnitude increase in the enzymatic activity is the highest amplification in the volume-confined enzyme reaction as reported. A near-exponential drop in the activity is observed with the increase in the space volume, revealing the dominant enhancement in the confined space at the fL level for the first time. The established electrochemical nanopipettes should not only provide a strategy for the study of the enzymatic activity in supersmall confined space but also help understand the confinement effect of enzyme-catalyzed reactions.


Assuntos
Glucose Oxidase , Peróxido de Hidrogênio , Glucose
8.
Nanoscale ; 13(42): 17737-17745, 2021 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-34697618

RESUMO

Mitochondria, as the energy factory of cells, often maintain a high redox state, and play an important role in cell growth, development and apoptosis. Therefore, the destruction of mitochondrial redox homeostasis has now become an important direction for cancer treatment. Here, we design a mitochondrial targeting composite enzyme nanogel bioreactor with a circulating supply of O2 and H2O2, which is composed of mitochondrial target triphenylphosphine (TPP), natural enzymes glucose oxidase (GOX) and catalase (CAT), and protoporphyrin IX (PpIX). The nanogel can effectively increase the stability of the natural enzymes, and its size of about 65 nm makes them close in space, which greatly improves their cascade catalytic efficiency and safety. Under the action of target TPP, the system can accurately target the mitochondria of breast cancer 4T1 cells, catalyze intracellular glucose to generate H2O2 through GOX, and H2O2 is further used as a catalytic substrate for CAT to generate O2. This O2 can not only further improve the catalytic efficiency of GOX, but also provide raw materials for the production of ROS in PDT, which can effectively destroy the mitochondria of cancer cells, thereby causing tumor cell apoptosis. Compared with GOX alone, thanks to the close spatial position of the composite enzymes, the composite enzyme nanogel can quickly consume the highly oxidative H2O2 produced by GOX, thereby showing better safety to normal cells. In addition, the composite enzyme group under light showed excellent antitumor effects by combining starvation therapy and PDT under adequate oxygen supply in animal experiments. In general, this composite enzyme nanogel system with good stability, high safety and excellent cascade catalytic efficiency opens a new way for the development of safe and efficient cancer therapeutics.


Assuntos
Fotoquimioterapia , Animais , Linhagem Celular Tumoral , Glucose Oxidase , Peróxido de Hidrogênio , Mitocôndrias , Nanogéis
9.
ACS Biomater Sci Eng ; 7(11): 5165-5174, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34704735

RESUMO

A DNA structure-based nanoreactor has emerged as a promising biomaterial for antitumor therapy with its intrinsic biodegradability, biocompatibility, and tunable multifunctionality. Herein, the intelligent DNA nanohydrogel was reported to target cancer cells, control the size, be pH-responsive, and be loaded with glucose oxidase (GOx). Two kinds of X-shaped DNA monomers and DNA linkers were assembled to form a DNA nanohydrogel by hybridization. GOx was successfully encapsulated in the DNA nanohydrogel. The DNA linker was designed with i-motif sequences and modified with ferrocene (Fc). The i-motif-like quadruplex structures were formed in acidic tumor microenvironments, resulting in the disassembly of the DNA nanohydrogel to release GOx. The GOx could oxidize the intratumoral glucose to produce gluconic acid and H2O2. The generated H2O2 was catalyzed by Fc to induce toxic hydroxyl radicals (•OH), which could effectively kill cancer cells. Both the in vitro and the in vivo results demonstrated that the multifunctional DNA nanohydrogel had high-efficiency tumor suppression through combined chemodynamic and starvation cancer therapies.


Assuntos
Neoplasias , Microambiente Tumoral , DNA/genética , Glucose Oxidase , Humanos , Peróxido de Hidrogênio , Neoplasias/tratamento farmacológico
10.
ACS Nano ; 15(10): 15645-15655, 2021 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-34623130

RESUMO

Enzymes have catalytic turnovers. The field of nanozyme endeavors to engineer nanomaterials as enzyme mimics. However, a discrepancy in the definition of "nanozyme concentration" has led to an unrealistic calculation of nanozyme catalytic turnovers. To date, most of the reported works have considered either the atomic concentration or nanoparticle (NP) concentration as nanozyme concentration. These assumptions can lead to a significant under- or overestimation of the catalytic activity of nanozymes. In this article, we review some classic nanozymes including Fe3O4, CeO2, and gold nanoparticles (AuNPs) with a focus on the reported catalytic activities. We argue that only the surface atoms should be considered as nanozyme active sites, and then the turnover numbers and rates were recalculated based on the surface atoms. According to the calculations, the catalytic turnover of peroxidase Fe3O4 NPs is validated. AuNPs are self-limited when performing glucose-oxidase like activity, but they are also true catalysts. For CeO2 NPs, a self-limited behavior is observed for both oxidase- and phosphatase-like activities due to the adsorption of reaction products. Moreover, the catalytic activity of single-atom nanozymes is discussed. Finally, a few suggestions for future research are proposed.


Assuntos
Ouro , Nanopartículas Metálicas , Catálise , Glucose Oxidase , Peroxidase
11.
Biomaterials ; 278: 121165, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34649197

RESUMO

Metformin is a clinically-approved anti-diabetic drug with emerging antitumor potential, but its antitumor activity is highly susceptible to local glucose abundance. Herein, we construct a nanotherapeutic platform based on biocompatible constituents to sensitize tumor cells for metformin therapy via cooperative glucose starvation. The nanoplatform was synthesized through the spontaneous biomineralization of glucose oxidase (GOx) and metformin in amorphous calcium phosphate nanosubstrate, which was further modified with polyethylene glycol and cRGD ligands. This biomineralized nanosystem could efficiently deliver the therapeutic payloads to tumor cells in a targeted and bioresponsive manner. Here GOx could catalyze the oxidation of glucose into gluconic acid and H2O2, thus depleting the glucose in tumor intracellular compartment while accelerating the release of the entrapped therapeutic payloads. The selective glucose deprivation would not only disrupt tumor energy metabolism, but also upregulate the PP2A regulatory subunit B56δ and sensitize tumor cells to the metformin-induced CIP2A inhibition, leading to efficient apoptosis induction via PP2A-GSK3ß-MCL-1 axis with negligible side effects. This study may offer new avenues for targeted tumor therapy in the clinical context.


Assuntos
Glucose , Metformina , Linhagem Celular Tumoral , Glucose Oxidase , Peróxido de Hidrogênio
12.
Nanoscale ; 13(35): 14900-14914, 2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34533163

RESUMO

The cascade catalytic strategy could effectively enhance the antibacterial activity by regulating the production of hydroxyl radicals (˙OH) in the sites of bacterial infection. In this work, a ruthenium metal nanoframe (Ru NF) was successfully synthesized via the palladium template method. The cascade catalysis in the bacterial infection microenvironment was achieved by physically adsorbed natural glucose oxidase (GOx), and hyaluronic acid (HA) was coated on the outer layer of the system for locating the infection sites accurately. Eventually, a composite nano-catalyst (HA-Ru NFs/GOx) based on the ruthenium nanoframe was constructed, which exhibited excellent cascade catalytic activity and good biocompatibility. The prepared HA-Ru NFs/GOx enhances the antibacterial activity and inhibits bacterial regeneration through the outbreak of reactive oxygen species (ROS) caused by self-activating cascade reactions. In addition, in vivo experiments indicate that HA-Ru NFs/GOx could efficiently cause bacterial death and significantly promote wound healing/skin regeneration. Accordingly, ruthenium metal framework nanozymes could be used as an effective cascade catalytic platform to inhibit bacterial regeneration and promote wound healing, and have great potential as new antibacterial agents against antibiotic-resistant bacteria.


Assuntos
Infecções Bacterianas , Rutênio , Antibacterianos/farmacologia , Infecções Bacterianas/tratamento farmacológico , Catálise , Glucose Oxidase , Humanos
13.
Mater Sci Eng C Mater Biol Appl ; 128: 112270, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474829

RESUMO

Glucose determination is one of the most common analyses in clinical chemistry. Employing biosensors for this purpose has become the method of choice for home use for diabetic patients. To limit the impact of dissolved O2 concentration or possible interferences (known hindrances in the classical glucose detection approach), a variety of mediated pathways have been explored. Herein, an ingenious, facile and low-cost approach for immobilization of redox mediator within nanofibrous mats is presented. This '2nd generation' biosensor is able to avoid common issues such as leaching or diffusion barriers whilst providing the necessary close contact between the enzyme and the redox shuttle, for enhancing the detection accuracy and accelerate the response. Polyacrylonitrile nanofibers loaded with carbon nanotubes and ferrocene (PAN/Fc/MWCNT-COOH NFs) have been successfully prepared and applied as biosensing matrices upon cross-linking of glucose oxidase (GOD). The morphology of the NFs was investigated by means of scanning electron microscopy (SEM-EDX) and correlated to the kinetics of mediated electron transfer and to the efficiency in glucose detection, which were evaluated through cyclic voltammetry (CV) and amperometric measurements. The content of Fc was varied from 0.5 to 5.0 wt%, with optimum biosensor performance at 1.0 wt% exhibiting a linear range up to 8.0 × 10-3 M with sensitivity of ~27.1 mAM-1 cm-2 and 4.0 µM LOD. Excellent stability (RSD 2.68%) during 40 consecutive measurements along with insignificant interference and accurate recovery in real sample analysis (~100%) make for a very reliable sensor that can easily render itself to miniaturization and has the potential for a wide range of practical applications.


Assuntos
Técnicas Biossensoriais , Nanofibras , Nanotubos de Carbono , Enzimas Imobilizadas , Glucose , Glucose Oxidase , Humanos , Metalocenos
14.
Phys Chem Chem Phys ; 23(36): 20709-20717, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34516596

RESUMO

It is usually assumed that enzymes retain their native structure during catalysis. However, the aggregation and fragmentation of proteins can be difficult to detect and sometimes conclusions are drawn based on the assumption that the protein is in its native form. We have examined three model enzymes, alkaline phosphatase (AkP), hexokinase (HK) and glucose oxidase (GOx). We find that these enzymes aggregate or fragment after addition of chemical species directly related to their catalysis. We used several independent techniques to study this behavior. Specifically, we found that glucose oxidase and hexokinase fragment in the presence of D-glucose but not L-glucose, while hexokinase aggregates in the presence of Mg2+ ion and either ATP or ADP at low pH. Alkaline phosphatase aggregates in the presence of Zn2+ ion and inorganic phosphate. The aggregation of hexokinase and alkaline phosphatase does not appear to attenuate their catalytic activity. Our study indicates that specific multimeric structures of native enzymes may not be retained during catalysis and suggests pathways for different enzymes to associate or separate over the course of substrate turnover.


Assuntos
Fosfatase Alcalina/química , Glucose Oxidase/química , Hexoquinase/química , Fosfatase Alcalina/metabolismo , Biocatálise , Glucose Oxidase/metabolismo , Hexoquinase/metabolismo , Modelos Moleculares , Estrutura Molecular , Agregados Proteicos
15.
Biomacromolecules ; 22(10): 4383-4394, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34533297

RESUMO

Typical glucose oxidase (GOx)-based starvation therapy is a promising strategy for tumor treatment; however, it is still difficult to achieve an effective therapeutic effect via a single starvation therapy. Herein, we designed a pH-sensitive polymeric vesicle (PV) self-assembled by histamine-modified chondroitin sulfate (CS-his) for codelivery of GOx and l-buthionine sulfoximine (BSO). GOx can consume glucose to induce the starvation therapy after the PVs reach cancer cell. Moreover, the product H2O2 will be reduced by a high concentration of glutathione (GSH) in the tumor cell, resulting in a reduction of the GSH content. The released BSO finally further reduced the GSH level. As a result, the signaling pathway of the ferroptosis will be activated. The in vivo results demonstrated that GOx/BSO@CS PVs exhibit a good inhibitory effect on the growth of 4T1 tumors in mice. Thus, this work provides a facile strategy to prepare pH-sensitive nanomedicine for synergistic starvation-ferroptosis therapy of tumor.


Assuntos
Ferroptose , Glucose Oxidase , Animais , Butionina Sulfoximina , Glutationa , Peróxido de Hidrogênio , Concentração de Íons de Hidrogênio , Camundongos
16.
Nanoscale ; 13(39): 16571-16588, 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34585187

RESUMO

Weak acidity (6.5-6.9) and limited H2O2 level in the tumor microenvironment (TME) usually impact the therapeutic effect of chemodynamic therapy (CDT) for cancer. A Specific TME promotes the formation of an immunosuppressive microenvironment and results in high rate of recurrence and metastasis of cancer. Fe3O4@ZIF-8/GOx@MnO2 multi-layer core shell nanostructure was constructed as a hybrid nanozyme. After magnetic targeting of the tumor site, the outermost MnO2 shell catalyzed H2O2 in TME to produce O2 and was broken due to the reaction with glutathione. Due to the acid response, the ZIF-8 layer would crack and release glucose oxidase (GOx) and Fe3O4. The generated O2 was utilized by GOx in starvation therapy to consume glucose and produce H2O2 and gluconic acid. The Fenton reaction efficiency of Fe(II) was improved by the increased H2O2 concentration and the enhanced acidity in TME. At the same time, the intrinsic photothermal effect of Fe3O4 upon 808 nm laser irradiation promoted the activity of MnO2 and GOx as oxidase, and Fe(II) as catalase-like, and ablated the primary tumor. Moreover, the hybrid nanozyme can facilitate the transformation of M2-type macrophages to M1-type, and strong systemic antitumor immune effect was induced. A synergy of multiple therapeutic modes including starvation therapy, CDT, photothermal therapy (PTT), and immunotherapy can be realized in the hybrid nanozyme for tumor therapy.


Assuntos
Glucose Oxidase , Neoplasias , Linhagem Celular Tumoral , Humanos , Peróxido de Hidrogênio , Compostos de Manganês , Neoplasias/terapia , Óxidos , Microambiente Tumoral
17.
Chem Commun (Camb) ; 57(74): 9398-9401, 2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34528964

RESUMO

A tumor cell membrane-camouflaged therapeutic system was fabricated to eliminate tumors by embedding apyrase and glucose oxidase (GOx) into zeolitic imidazolate framework-8 (ZIF-8) nanoparticles for tumor-targeted metabolic therapy. Experimental results demonstrated that these functional nanoparticles could disturb the energy supply of tumor cells by depleting ATP and glucose and efficiently induce tumor cell death.


Assuntos
Apirase/metabolismo , Materiais Biomiméticos/metabolismo , Glucose Oxidase/metabolismo , Estruturas Metalorgânicas/metabolismo , Nanopartículas/metabolismo , Neoplasias/metabolismo , Trifosfato de Adenosina/metabolismo , Materiais Biomiméticos/química , Morte Celular/efeitos dos fármacos , Glucose/metabolismo , Humanos , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Nanopartículas/química , Neoplasias/tratamento farmacológico , Neoplasias/patologia
18.
Analyst ; 146(21): 6576-6581, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34586111

RESUMO

The accurate and sensitive detection of glucose from secretory clinical samples, such as tears and saliva, remains a great challenge. In this research, a novel ultrasensitive glucose detection method consisting of a glucose oxidase (GOx), pistol-like DNAzyme (PLDz), and CRISPR-Cas12a system is proposed. First, the oxidation of glucose catalyzed by GOx leads to the production of H2O2; the self-cleavage activity of PLDz is activated after recognition of the produced H2O2. The two procedures triggered by COx and PLDz play an important role in accurately identifying glucose and converting glucose signals to nucleic acids. The obtained PLDz fragments can be recognized by the Cas12 enzyme and thus activate the trans-cleavage activity of the Cas12a enzyme. Finally, the surrounding reporter probes are cut by the Cas12a enzyme to produce fluorescence signals. In summary, an ultra-sensitive and specific fluorescence method has been developed for glucose detection from secretory clinical samples, which could potentially contribute to the noninvasive diagnosis of diabetes mellitus.


Assuntos
Técnicas Biossensoriais , DNA Catalítico , Sistemas CRISPR-Cas , Glucose , Glucose Oxidase , Peróxido de Hidrogênio , Saliva
19.
Molecules ; 26(18)2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34577080

RESUMO

The selective disruption of nutritional supplements and the metabolic routes of cancer cells offer a promising opportunity for more efficient cancer therapeutics. Herein, a biomimetic cascade polymer nanoreactor (GOx/CAT-NC) was fabricated by encapsulating glucose oxidase (GOx) and catalase (CAT) in a porphyrin polymer nanocapsule for combined starvation and photodynamic anticancer therapy. Internalized by cancer cells, the GOx/CAT-NCs facilitate microenvironmental oxidation by catalyzing endogenous H2O2 to form O2, thereby accelerating intracellular glucose catabolism and enhancing cytotoxic singlet oxygen (1O2) production with infrared irradiation. The GOx/CAT-NCs have demonstrated synergistic advantages in long-term starvation therapy and powerful photodynamic therapy (PDT) in cancer treatment, which inhibits tumor cells at more than twice the rate of starvation therapy alone. The biomimetic polymer nanoreactor will further contribute to the advancement of complementary modes of spatiotemporal control of cancer therapy.


Assuntos
Nanopartículas/química , Neoplasias/terapia , Fotoquimioterapia/métodos , Polímeros/química , Animais , Biomimética , Catalase/química , Catalase/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Glucose Oxidase/química , Glucose Oxidase/farmacologia , Humanos , Peróxido de Hidrogênio/metabolismo , Raios Infravermelhos , Camundongos , Polímeros/síntese química , Porfirinas/síntese química , Porfirinas/química , Oxigênio Singlete/metabolismo , Oxigênio Singlete/farmacologia
20.
Biomater Sci ; 9(18): 6116-6125, 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34519735

RESUMO

Single tumor starvation therapy can activate other signaling pathways in tumor cells and easily induce tumor cell metastasis. This research proposes an intelligent nanoparticle, which is effectively combined with plasmonic and immunotherapy to realize a new strategy of "upstream consumption and downstream blocking" of nutrients in tumor sites. The intelligent nanoparticle (Ag-G/C@M) was composed of Ag NCs loaded with glucose oxidase (GOx), catalase (CAT) and coated with the tumor cytomembrane (M). Homologous targeting of tumor cytomembrane facilitated more delivery of Ag-G/C@M to tumor sites and then the plasmonic excited from Ag-G/C@M can increase the catalytic efficiency of the enzymatic reaction. Hydrogen peroxide (H2O2) produced by Ag-G/C@M through the consumption of glucose is further catalyzed by CAT to produce oxygen (O2). This self-reinforcing cascade reaction not only consumes the nutrients of tumor cells, but also the plasmonic-induced photothermal therapy can further stimulate the immune system to produce interferon-γ (IFN-γ), blocking angiogenesis and restricting the nutrient supply of tumor cells. This strategy takes the nutrition necessary for cell survival as the entry point, through endogenous continuous consumption of intracellular nutrients and containment of exogenous supplementation, combined with plasmonic thermal effect and immunotherapy to kill tumor cells, which provides a new way of treating cancer safely and effectively.


Assuntos
Nanopartículas , Neoplasias , Catálise , Glucose Oxidase , Humanos , Peróxido de Hidrogênio , Neoplasias/terapia , Terapia Fototérmica
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