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1.
Microbiol Res ; 230: 126330, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31541842

RESUMO

Glycoconjugates found on cell walls of Candida species are fundamental for their pathogenicity. Laborious techniques have been employed to investigate the sugar composition of these microorganisms. Herein, we prepared a nanotool, based on the fluorescence of quantum dots (QDs) combined with the specificity of Cramoll lectin, to evaluate glucose/mannose profiles on three Candida species. The QDs-Cramoll conjugates presented specificity and bright fluorescence emission. The lectin preserved its biological activity after the conjugation process mediated by adsorption interactions. The labeling of Candida species was analyzed by fluorescence microscopy and quantified by flow cytometry. Morphological analyses of yeasts labeled with QDs-Cramoll conjugates indicated that C. glabrata (2.7 µm) was smaller when compared to C. albicans (4.0 µm) and C. parapsilosis sensu stricto (3.8 µm). Also, C. parapsilosis population was heterogeneous, presenting rod-shaped blastoconidia. More than 90% of cells of the three species were labeled by conjugates. Inhibition and saturation assays indicated that C. parapsilosis had a higher content of exposed glucose/mannose than the other two species. Therefore, QDs-Cramoll conjugates demonstrated to be effective fluorescent nanoprobes for evaluation of glucose/mannose constitution on the cell walls of fungal species frequently involved in candidiasis.


Assuntos
Candida/química , Corantes Fluorescentes/química , Glucose/análise , Lectinas/química , Manose/análise , Microscopia de Fluorescência/métodos , Candida/crescimento & desenvolvimento , Candida/isolamento & purificação , Candida/metabolismo , Candidíase/diagnóstico , Candidíase/microbiologia , Parede Celular/química , Parede Celular/metabolismo , Glucose/metabolismo , Humanos , Manose/metabolismo , Microscopia de Fluorescência/instrumentação , Nanopartículas/química , Pontos Quânticos/química
2.
Talanta ; 206: 120211, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514873

RESUMO

Urinary glucose determination using a glucose test strip is simple and convenient in daily self-monitoring of diabetes. However, diabetic patients exhibit acquired impaired color vision (ICV), which results in the inability to discriminate between hues. Even with the assistance of a color chart, it is still not easy for these patients to read the urinary glucose results with the naked eye. In this study, a smartphone camera using an image-based colorimetric detection method was successfully developed for quantitative analysis of urine glucose. A horseradish peroxidase-hydrogen peroxide-3,3'5,5'-tetramethylbenzidine (HRP-H2O2-TMB) system was optimized for a reliable and gradual color fading process via a glucose oxidase (GOD) catalyzed oxidation reaction. The color changes of the peroxidase-H2O2 enzymatic reactions in the 96-well microplate were captured by a smartphone RGB camera with subsequent detection of red, green, and blue (RGB) intensities decreasing at each image pixel. The highly quantitative relationships between the glucose concentrations and the color characteristic values of the blue channel of the captured images were successfully established. The high accuracy of this method was demonstrated in urine glucose measurements with a linear response over the 0.039 mg mL-1 to 10.000 mg mL-1 glucose concentration range and a 0.009 mg mL-1 detection limit. The method has great potential as a point-of-need platform for diabetic patients with defective color vision and features high accuracy and low cost.


Assuntos
Diabetes Mellitus/urina , Glucose/análise , Glicosúria/diagnóstico , Smartphone , Armoracia/enzimologia , Benzidinas/química , Compostos Cromogênicos/química , Colorimetria/métodos , Glucose/química , Glucose Oxidase/química , Peroxidase do Rábano Silvestre/química , Humanos , Peróxido de Hidrogênio/química , Limite de Detecção , Fotografação/instrumentação , Testes Imediatos
3.
Anal Bioanal Chem ; 412(4): 963-972, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31853600

RESUMO

In this study, palladium/carbon dot composites (Pd-CDs) were fabricated via a facial hydrothermal route using ethanediamine and palladium chloride dihydrate as precursors. The obtained Pd-CDs showed an excellent intrinsic peroxidase-like activity, which could catalyze the oxidization of 3,3'5,5'-tetramethylbenzidine with the assistance of hydrogen peroxide (H2O2) and thus resulted in color change, accompanied by an absorption peak which appeared at 652 nm. Such response is H2O2 concentration-dependent and allows for the assay of H2O2 in the range of 0.1 to 30 µM with a limit of detection of 0.03 µM. Simultaneously, by combination of enzymatic oxidation of glucose with glucose oxidase and Pd-CD catalytic reaction, a colorimetric sensing platform was also constructed for glucose detection with high selectivity and sensitivity (limit of detection as low as 0.2 µM). Additionally, the proposed method exhibited capability for determination of glucose in real samples (fruit juice) with satisfactory recovery (98.5-103%), indicating potential application prospects in biochemical analysis.


Assuntos
Carbono/química , Glucose/análise , Peróxido de Hidrogênio/análise , Paládio/química , Benzidinas/química , Materiais Biomiméticos/química , Técnicas Biossensoriais/métodos , Colorimetria/métodos , Análise de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Limite de Detecção , Oxirredução , Peroxidase/química
4.
Talanta ; 207: 120289, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31594584

RESUMO

Recently, the aggregation-induced emission (AIE) of nanoclusters triggered by metal ions has been received great attentions. However, the good AIE efficiency usually requires excessive metal ions, which may result in an undesired competition between metal ions and targets. In this work, by the synergistic effect of Pb2+ and Zr4+, a fewer amounts of metal ions can induce more aggregates of glutathione-capped Cu nanoclusters (CSH-CuNCs), resulting in a higher AIE efficiency. Next, by virtue of the oxidative property of H2O2, the AIE of GSH-CuNCs-Pb2+-Zr4+ system quenches linearly with the concentration of H2O2 from 1 to 60 µmol/L. Moreover, many biological substrates, such as glucose and cholesterol, can generate H2O2 in the presence of their specific oxidases and O2. Therefore, the detection of glucose or cholesterol can also be achieved by the proposed method, and the limits of detection of glucose and cholesterol are 0.37 and 2.7 µmol/L, respectively. Finally, this method has been validated to be sensitive and selective for glucose or cholesterol detection in human serum samples.


Assuntos
Cobre/química , Peróxido de Hidrogênio/análise , Chumbo/química , Nanopartículas Metálicas/química , Zircônio/química , Glicemia/análise , Colesterol/sangue , Glucose/análise , Glutationa/química , Humanos , Limite de Detecção , Espectrometria de Fluorescência
5.
Food Chem ; 309: 125686, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31670130

RESUMO

Reducing sugars can react with 1-phenyl-3-methyl-5-pyrazolone (PMP) to form sugar-PMP derivatives, which can be detected by HPLC-UV or HPLC-DAD due to their high UV absorbance at 248 nm. Six different sugars were synthesized with PMP with aid of response surface methodology (RSM), by which the parameters of the synthesis were designed within temperature ranged between 60 °C and 90 °C, and time from 60 to 180 min, respectively. Consequently, optimal conditions of the glucose (Glu)-, glucosamine (GluN)-, galactose (Gal)-, glucuronic acid (GluA), galacturonic acid (GalA) and glucose-6-phosphate (G6P-PMP) reactions were determined at 71 °C for 129 min, 73 °C for 96 min, 70 °C for 117 min, 75 °C for 151 min, 76 °C for 144 min, and 70 °C for 154 min, respectively. Experiments demonstrated that unique functional groups and delicate differences of carbohydrates' inner pH environment could significantly influence the sugar-PMP reactions. However, sugar stereoisomers did not have remarkable impacts on the reactions.


Assuntos
Carboidratos/análise , Carboidratos/química , Edaravone/química , Cromatografia Líquida de Alta Pressão , Galactose/análise , Galactose/química , Glucosamina/análise , Glucosamina/química , Glucose/análise , Glucose/química , Glucose-6-Fosfato/análise , Glucose-6-Fosfato/química , Ácido Glucurônico/análise , Ácido Glucurônico/química , Ácidos Hexurônicos/análise , Ácidos Hexurônicos/química , Estereoisomerismo
6.
Analyst ; 144(24): 7192-7199, 2019 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-31696868

RESUMO

The magic angle coil spinning (MACS) technique has been introduced as a very promising extension for solid state NMR detection, demonstrating sensitivity enhancements by a factor of 14 from the very first time it has been reported. The main beneficiary of this technique is the scientific community dealing with mass- and volume-limited, rare, or expensive samples. However, more than a decade after the first report on MACS, there is a very limited number of groups who have continued to develop the technique, let alone it being widely adopted by practitioners. This might be due to several drawbacks associated with the MACS technology until now, including spectral linewidth, heating due to eddy currents, and imprecise manufacturing. Here, we report a device overcoming all these remaining issues, therefore achieving: (1) spectral resolution of approx 0.01 ppm and normalized limit of detection of approx. 13 nmol s0.5 calculated using the anomeric proton of sucrose at 3 kHz MAS frequency; (2) limited temperature increase inside the MACS insert of only 5 °C at 5 kHz MAS frequency in an 11.74 T magnetic field, rendering MACS suitable to study live biological samples. The wafer-scale fabrication process yields MACS inserts with reproducible properties, readily available to be used on a large scale in bio-chemistry labs. To illustrate the potential of these devices for metabolomic studies, we further report on: (3) ultra-fine 1H-1H and 13C-13C J-couplings resolved within 10 min for a 340 mM uniformly 13C-labeled glucose sample; and (4) single zebrafish embryo measurements through 1H-1H COSY within 4.5 h, opening the gate for the single embryo NMR studies.


Assuntos
Embrião não Mamífero/metabolismo , Glucose/análise , Metabolômica , Ressonância Magnética Nuclear Biomolecular/instrumentação , Peixe-Zebra/embriologia , Animais , Caenorhabditis elegans , Campos Magnéticos , Metabolômica/métodos
8.
Int J Nanomedicine ; 14: 7851-7860, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632005

RESUMO

Background: Gestational diabetes mellitus is a commonly occurring metabolic disorder during pregnancy, affecting >4% of pregnant women. It is generally defined as the intolerance of glucose with the onset or initial diagnosis during pregnancy. This illness affects the placenta and poses a threat to the baby as it affects the supply of proper oxygen and nutrients. Purpose: Due to the high percentage of affected pregnant women, it should be mandatory to evaluate glucose levels during pregnancy and there is a need for a continuous monitoring system. Methods: Herein, the investigators modified the interdigitated (di)electrodes (IDE) sensing surface to detect the glucose on covalently immobilized glucose oxidase (GOx) with the graphene. The characterization of graphene and gold nanoparticle (GNP) was performed by high-resolution microscopy. Results: Sensitivity was found to be 0.06 mg/mL and to enhance the detection, GOx was complexed with GNP. GNP-GOx was improved the sensitive detection twofold from 0.06 to 0.03 mg/mL, and it also displayed higher levels of current changes at all the concentrations of glucose that were tested. High-performance of the above IDE sensing system was attested by the specificity, reproducibility and higher sensitivity detections. Further, the linear regression analysis indicated the limit of detection to be between 0.02 and 0.03 mg/mL. Conclusion: This study demonstrated the potential strategy with nanocomposite for diagnosing gestational diabetes mellitus.


Assuntos
Diabetes Gestacional/diagnóstico , Eletricidade , Glucose Oxidase/metabolismo , Glucose/análise , Ouro/química , Grafite/química , Nanocompostos/química , Eletrodos , Feminino , Humanos , Limite de Detecção , Modelos Lineares , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Nanocompostos/ultraestrutura , Gravidez , Sensibilidade e Especificidade , Propriedades de Superfície
9.
Int J Nanomedicine ; 14: 8059-8072, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632018

RESUMO

Background: Compared with random copolymers, block copolymerization is easier to prepare for nanoparticles with core-shell structure, and they will have better glucose sensitivity and higher insulin loading. Purpose: In our study, insulin-loaded poly (3-acrylamidophenylboronic acid-block-N-vinyl caprolactam) p(AAPBA-b-NVCL) nanoparticles were successfully prepared and were glucose-sensitive, which could effectively lower the blood sugar levels within 72 hrs. Methods: The polymer of p(AAPBA-b-NVCL) was produced by reversible addition-fragmentation chain transfer polymerization based on different ratios of 3-acrylamidophenylboronic acid (AAPBA) and N-vinylcaprolactam (NVCL), and its structure was discussed by Fourier transform infrared spectroscopy and 1H-nuclear magnetic resonance . Next, the polymer was manufactured into the nanoparticles, and the characteristics of nanoparticles were detected by dynamic light scattering, lower critical solution temperature, and transmission electron microscopy. After that, the cell and animal toxicity of nanoparticles were also investigated. Results: The results demonstrated that p(AAPBA-b-NVCL) was successfully synthesized, and can be easily self-assembled to form nanoparticles. The new nanoparticles included monodisperse submicron particles, with the size of the nanoparticle ranged between 150 and 300nm and are glucose- and temperature-sensitive. Meanwhile, insulin can be easily loaded by p(AAPBA-b-NVCL) nanoparticles and an effective sustained release of insulin was observed when the nanoparticles were placed in physiological saline. Besides, MTT assay revealed that cell viability was more than 80%, and mice demonstrated no negative impact on blood biochemistry and heart, liver, spleen, lung, and kidney after intraperitoneal injection of 10 mg/kg/d of nanoparticles. This suggested that the nanoparticles were low-toxic to both cells and animals. Moreover, they could lower the blood sugar level within 72h. Conclusion: Our research suggested that these p(AAPBA-b-NVCL) nanoparticles might have the potential to be applied in a delivery system for insulin or other hypoglycemic proteins.


Assuntos
Acrilamidas/química , Ácidos Borônicos/química , Caprolactama/química , Sistemas de Liberação de Medicamentos , Glucose/análise , Insulina/administração & dosagem , Nanopartículas/química , Acrilamidas/síntese química , Animais , Glicemia/metabolismo , Ácidos Borônicos/síntese química , Caprolactama/análogos & derivados , Caprolactama/síntese química , Sobrevivência Celular/efeitos dos fármacos , Feminino , Hidrodinâmica , Concentração de Íons de Hidrogênio , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/farmacologia , Masculino , Camundongos , Células NIH 3T3 , Nanopartículas/ultraestrutura , Espectroscopia de Prótons por Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Temperatura Ambiente
10.
Nature ; 574(7779): 559-564, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31645735

RESUMO

Although glucose-sensing neurons were identified more than 50 years ago, the physiological role of glucose sensing in metazoans remains unclear. Here we identify a pair of glucose-sensing neurons with bifurcated axons in the brain of Drosophila. One axon branch projects to insulin-producing cells to trigger the release of Drosophila insulin-like peptide 2 (dilp2) and the other extends to adipokinetic hormone (AKH)-producing cells to inhibit secretion of AKH, the fly analogue of glucagon. These axonal branches undergo synaptic remodelling in response to changes in their internal energy status. Silencing of these glucose-sensing neurons largely disabled the response of insulin-producing cells to glucose and dilp2 secretion, disinhibited AKH secretion in corpora cardiaca and caused hyperglycaemia, a hallmark feature of diabetes mellitus. We propose that these glucose-sensing neurons maintain glucose homeostasis by promoting the secretion of dilp2 and suppressing the release of AKH when haemolymph glucose levels are high.


Assuntos
Encéfalo/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/metabolismo , Glucagon/metabolismo , Glucose/metabolismo , Insulina/metabolismo , Neurônios/metabolismo , Animais , Axônios/metabolismo , Encéfalo/anatomia & histologia , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/anatomia & histologia , Glucose/análise , Hormônios de Inseto/metabolismo , Masculino , Inibição Neural , Vias Neurais , Neuropeptídeos/química , Neuropeptídeos/metabolismo , Neurotransmissores/metabolismo , Oligopeptídeos/metabolismo , Ácido Pirrolidonocarboxílico/análogos & derivados , Ácido Pirrolidonocarboxílico/metabolismo
11.
ACS Appl Mater Interfaces ; 11(40): 37347-37356, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31502433

RESUMO

Noninvasive real-time biosensors to measure glucose levels in the body fluids have been widely investigated for continuous glucose monitoring of diabetic patients. However, they suffered from low sensitivity and reproducibility due to the instability of nanomaterials used for glucose biosensors. Here, we developed a hyaluronate-gold nanoparticle/glucose oxidase (HA-AuNP/GOx) complex and an ultralow-power application-specific integrated circuit chip for noninvasive and robust wireless patch-type glucose sensors. The HA-AuNP/GOx complex was prepared by the facile conjugation of thiolated HA to AuNPs and the following physical binding of GOx. The wireless glucose sensor exhibited slow water evaporation (0.11 µL/min), fast response (5 s), high sensitivity (12.37 µA·dL/mg·cm2) and selectivity, a low detection limit (0.5 mg/dL), and highly stable enzymatic activity (∼14 days). We successfully demonstrated the strong correlation between glucose concentrations measured by a commercially available blood glucometer and the wireless patch-type glucose sensor. Taken together, we could confirm the feasibility of the wireless patch-type robust glucose sensor for noninvasive and continuous diabetic diagnosis.


Assuntos
Técnicas Biossensoriais/métodos , Glucose Oxidase/metabolismo , Glucose/análise , Ouro/química , Ácido Hialurônico/química , Nanopartículas Metálicas/química , Tecnologia sem Fio , Animais , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus
12.
Mater Sci Eng C Mater Biol Appl ; 105: 110075, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546385

RESUMO

A novel amine terminated multiwall carbon nanotubes/polyaniline/reduced graphene oxide/gold nanoparticles modified screen-printed carbon electrode (SPCE) was fabricated. Followed by, glucose oxidase (GOx) was immobilized on SPCE for highly sensitive glucose biosensor. The synthesized nanomaterial and their composites were characterized using scanning electron microscope (SEM) and UV-Visible spectroscopy. The electrochemical analysis has been followed at different stages of glucose oxidase coating on modified SPCE using cyclic voltammetry. The reduction current has enhanced 13.43 times with the lowest working potential by the modified SPCE when compared to bare SPCE. The glucose biosensor exhibited good reproducibility (90.23%, n = 7), high stability (after 30 days 96% at -20 °C storage, 2 week 74.5% at -4 °C storage), wide linear range (1-10 mM), less KMapp value (0.734), lowest detection limit (64 µM) and good sensitivity (246 µ Acm-2 mM-1). The biosensor was validated for the detection of glucose level in human blood serum samples using the amperometric technique. As designed nanocomposite based SPCE has the potential for an efficient glucose sensor, which also enabled the platform for various biochemical sensors.


Assuntos
Compostos de Anilina/química , Glucose Oxidase/química , Glucose/análise , Ouro/química , Grafite/química , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , Eletrodos
13.
Mater Sci Eng C Mater Biol Appl ; 105: 110069, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546439

RESUMO

The development of biosensing interfaces based on copolymerization of benzenamine-2,5-di(thienyl)pyrrole (SNS-An) with 3,4-ethylenedioxythiophene (EDOT) is reported. Both homopolymer P(SNS-An) and copolymer P(SNS-An-co-EDOT) films were prepared and evaluated, in terms of biosensing efficiency, upon incorporation of carbon nanoelements (carbon nanotubes and fullerene) and cross-linking of glucose oxidase. The copolymer revealed superior performance as a biosensing interface as compared to the homopolymer structure or previously reported P(SNS) biosensors. The analytical characteristics and stability studies were performed both at cathodic potential, monitoring O2 consumption, as a result of catalytic reaction of glucose oxidase towards glucose and at anodic potential, following the oxidation of the H2O2 produced during the catalytic reaction. Whilst the measurements on the positive side offered an extended linear range (0.01-5.0 mM), the negative side provided sensitivity up to 104.96 µA/mMcm-1 within a shorter range. Detection limits were as low as 1.9 µM with Km value of 0.49 mM. Lastly, the most performant biosensing platforms, including copolymeric structure and CNTs were employed for analysis in real samples.


Assuntos
Aspergillus niger/enzimologia , Técnicas Biossensoriais , Enzimas Imobilizadas/química , Fulerenos/química , Proteínas Fúngicas/química , Glucose Oxidase/química , Glucose/análise , Nanotubos de Carbono/química , Polímeros , Pirróis
14.
Mater Sci Eng C Mater Biol Appl ; 105: 110120, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546467

RESUMO

Glucose detection is of great importance for the medical diagnosis, food biotechnology and pharmaceutical analysis. In this study, we synthesized a core-shell CuS-Cu2S decorated carbon nanotube-graphene nanocomposite via a facile hydrothermal method. It exhibits great sensing performance towards glucose with wide linear range ranging from 0.001 to 2 mM, ultra-sensitivity of 1923 µA·cm-2·mM-1 and 0.33 µM detection limit in alkaline solutions. The excellent electrocatalytic activity originates from the synergistic effect between heterogeneous copper sulfides structures and carbon nanomaterials. Besides, the fabricate sensor also has great durability, selectivity and great potential for practical applications.


Assuntos
Cobre/química , Glucose/análise , Nanocompostos/química , Glicemia/análise , Catálise , Técnicas Eletroquímicas , Eletrodos , Grafite/química , Humanos , Concentração de Íons de Hidrogênio , Nanocompostos/ultraestrutura , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Oxirredução , Reprodutibilidade dos Testes
15.
BMC Complement Altern Med ; 19(1): 244, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488111

RESUMO

BACKGROUND: Catalpol, a natural iridoid glycoside in Rehmannia glutinosa, can alleviate proteinuria associated with diabetic nephropathy (DN), however, whether catalpol has a protective effect against podocyte injury in DN remains unclear. METHODS: In this study, we used a high glucose (HG)-induced podocyte injury model to evaluate the protective effect and mechanism of catalpol against HG-induced podocyte injury. Cell viability was determined by the 3-(4,5-dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The levels of lactate dehydrogenase (LDH), superoxide dismutase (SOD) and malondialdehyde (MDA) were measured by commercial assay kits. Cell apoptosis and reactive oxygen species (ROS) were determined by using flow cytometry. Tumour necrosis factor α (TNF-α), interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) levels were determined by enzyme-linked immunosorbent assay (ELISA). The protein expression levels of B-cell lymphoma-2 (Bcl-2), Bcl2-associated x (Bax), cleaved caspase-3, nicotinamide adenine dinucleotide phosphate oxidase enzyme 4 (NOX4), toll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MyD88), p38 mitogen-activated protein kinase (p38 MAPK), phosphorylated p38 MAPK (p-p38 MAPK), nuclear factor kappa B inhibitor alpha (IκBα) and phosphorylated IκBα (p-IκBα) were measured by western blotting. In addition, Bcl-2, Bax, caspase-3 and nuclear factor kappa B (NF-κB) levels were determined by immunofluorescence staining. RESULTS: Catalpol significantly increased cell viability and decreased LDH release in HG-induced podocyte injury. Catalpol significantly decreased ROS generation, apoptosis, level of MDA, levels of inflammatory cytokine TNF-α, IL-1ß, and IL-6 and increased SOD activity in HG-induced podocyte injury. Moreover, catalpol significantly decreased expression of cleaved caspase-3, Bax, NOX4, TLR4, MyD88, p-p38 MAPK, p-IκBα and NF-κB nuclear translocation, as well as increased Bcl-2 expression in HG-induced podocyte injury. CONCLUSION: Catalpol can protect against podocyte injury by ameliorating apoptosis and inflammation. These protective effects may be attributed to the inhibition of NOX4, which alleviates ROS generation and suppression of the TLR4/MyD88 and p38 MAPK signaling pathways to prevent NF-κB activation. Therefore, catalpol could be a promising drug for the prevention of DN.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Glucose/efeitos adversos , Glucosídeos Iridoides/farmacologia , Podócitos/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Glucose/análise , Glucose/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Camundongos , NF-kappa B/genética , NF-kappa B/metabolismo , Podócitos/citologia , Podócitos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Rehmannia/química , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
16.
Analyst ; 144(19): 5717-5723, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31482883

RESUMO

An innovative visible light-driven photoelectrochemical (PEC) immunosensing system was reasonably established for the sensitive detection of prostate-specific antigen (PSA) by using perovskite metal oxide@gold nanoparticle heterostructures (BaTiO3/Au) as the photoactive materials. When plasmonic Au nanoparticles were directly decorated on BaTiO3, a several times surface plasmon resonance (SPR) enhancement of photocurrent density was induced via the injection of hot electrons from visible light-excited Au nanoparticles into the conduction band of BaTiO3, and the combination of BaTiO3 and Au nanoparticles was employed as a promising platform for developing a photoelectrochemical bioanalysis. As a proof of concept, PSA had been detected by the BaTiO3/Au nanocomposite-based PEC sensor. To design such an immunoassay protocol, a monoclonal anti-PSA capture antibody (cAb)-coated microplate and glucose oxidase/polyclonal anti-PSA detection antibody-modified gold nanoparticles (GOx-Au NP-dAb) were used as the immunoreaction platform and signal probe, respectively. Upon the addition of target PSA, a sandwiched immunocomplex was formed accompanying the immuno-recognition between the antigen and antibody, and then the carried GOx could oxidize glucose to produce H2O2. The photocurrent of the BaTiO3/Au nanocomposite-functionalized electrode amplified with increasing H2O2 concentration since H2O2 is considered as a good hole scavenger. On the basis of the above-mentioned mechanisms and the optimized conditions, the assembled PEC immunosensor was linear with the logarithm of the PSA concentration in the range of 0.01-40 ng mL-1 with a detection limit of 4.2 pg mL-1. It afforded rapid response, good precision, and high stability and specificity, implying its great promise in photoelectrochemical immunoassays. More generally, this system sets up an ideal PEC immunosensing system based on the BaTiO3/Au nanocomposites and represents an innovative and low-cost "signal-on" assay scheme for the practical quantitative screening of low-abundance proteins.


Assuntos
Compostos de Bário/química , Ouro/química , Calicreínas/sangue , Nanopartículas Metálicas/química , Antígeno Prostático Específico/sangue , Titânio/química , Anticorpos Monoclonais/imunologia , Compostos de Bário/efeitos da radiação , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Glucose/análise , Glucose Oxidase/química , Ouro/efeitos da radiação , Humanos , Peróxido de Hidrogênio/química , Imunoensaio/métodos , Calicreínas/imunologia , Luz , Limite de Detecção , Nanopartículas Metálicas/efeitos da radiação , Nanocompostos/química , Nanocompostos/efeitos da radiação , Processos Fotoquímicos , Estudo de Prova de Conceito , Antígeno Prostático Específico/imunologia , Ressonância de Plasmônio de Superfície/métodos , Titânio/efeitos da radiação
17.
Biosens Bioelectron ; 142: 111547, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31387025

RESUMO

Glucose sensing is of vital importance due to the growing number of diabetes. In this study, we developed a visual detecting approach for glucose sensing based on a smart hydrogel system, by assembling of a photo-crosslinkable hydrogel and a pH-responsive nanogel, respectively. The hydrogel system showed fast response and high sensitivity to glucose in the physiological ranges, and enabled a visual detection of glucose both in vitro in glucose solutions and in vivo in diabetic mouse models. In normoglycemic state, the hydrogels showed large swelling, resulting in a large shape but with weak color or fluorescence intensity of the hydrogels. In hyperglycemic state, the hydrogels exhibited less swelling, resulting in a small shape but with strong color or fluorescence intensity of the hydrogels. Based on the observation of the size change and intensity change of the hydrogels, we can visual the glucose levels by either colorimetry or fluorescence imaging. This hydrogel system provides a novel means for visual detection of glucose. Our study broadens the current applications of hydrogels, extending their potentials in clinical diagnosis of diabetes or glucose-related analysis.


Assuntos
Acrilatos/química , Técnicas Biossensoriais/métodos , Glicemia/análise , Carboximetilcelulose Sódica/química , Gelatina/química , Hidrogéis/química , Animais , Colorimetria/métodos , Preparações de Ação Retardada/química , Diabetes Mellitus Experimental/sangue , Glucose/análise , Concentração de Íons de Hidrogênio , Luz , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus
18.
Biosens Bioelectron ; 142: 111545, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31376712

RESUMO

We propose a spectral contrast method to map the transmission images of surface plasmon resonance (SPR) in metallic nanostructures. Comparing the intensities between two neighboring wavelength bands near the SPR wavelength, the signal-to-noise ratio for biosensing applications obtained using the proposed method is found to be ten times higher than that obtained by conventional intensity analysis and 1.6 times better than that obtained by peak-wavelength fitting. The dynamic range and linearity of the refractive index are comparable to the peak-wavelength shift measurement. Based on the detection method, a spectral modulation system for the optical microscope is developed, combined with a gold-capped nanowire array, to measure the biointeractions in microfluidic devices. The experimental results show that the proposed method obtained multiple detections with a detection limit of 1.04 × 10-5 refractive index units. Two types of analysis methods for SPR images are used to study the protein-antibody interactions. The region-of-interest analysis supports multiplexing detections in a compact microfluidic sensor. The effective pixel analysis eliminates low-response pixels and enhances the signal-to-noise ratios for sensitive label-free detection.


Assuntos
Ouro/química , Nanoestruturas/química , Imagem Óptica/métodos , Ressonância de Plasmônio de Superfície/métodos , Desenho de Equipamento , Glucose/análise , Nanofios/química , Imagem Óptica/instrumentação , Refratometria , Ressonância de Plasmônio de Superfície/instrumentação
19.
Curr Microbiol ; 76(11): 1238-1246, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31377819

RESUMO

Streptococcus mutans (S. mutans) adheres to the tooth surface, metabolizes carbohydrates, and produces acid products, leading to enamel demineralization-the onset of dental caries. Rapid acidification by S. mutans has been observed in the presence of glucose. However, little is known about the role of small RNAs (sRNAs) in S. mutans in the presence of glucose and their relationship to tooth adherence. The objective of this study was to evaluate the role of sRNAs in S. mutans (18-50 nucleotides) regarding adherence capacity under 1% and 5% glucose concentrations. The pH drop and adherence capacity in the 1% glucose condition were similar to these parameters under conditions of 5% sucrose that were published in our previous study. A total of 2149 candidate sRNA with at least 100 average reads in the 5% and 1% glucose libraries were obtained. Between the two libraries, 581 sRNAs were differentially expressed and 43 sRNAs were verified. However, the expression levels of the predicted target genes gtfC and spaP were similar between the 1% and 5% glucose conditions. The bioinformatic analysis suggested that differentially expressed sRNAs may be involved in several pathways. These findings indicate that sRNAs were induced under these glucose concentrations and a series of sRNAs were specifically induced, respectively. sRNAs that are induced under glucose stress may be involved in regulating adherence of S. mutans.


Assuntos
Aderência Bacteriana , Glucose/análise , RNA Bacteriano/metabolismo , Streptococcus mutans/fisiologia , Cárie Dentária/microbiologia , Regulação Bacteriana da Expressão Gênica , Glucose/metabolismo , Humanos , RNA Bacteriano/genética , Streptococcus mutans/genética , Streptococcus mutans/crescimento & desenvolvimento , Sacarose/metabolismo
20.
Analyst ; 144(18): 5455-5461, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31432811

RESUMO

Over the past few years, artificial enzymes have attracted enormous attention due to their high stabilities and cost-effective productions. In this work, metal-organic framework-derived SiW12@Co3O4 was synthesized in large quantities by stirring the mixture at ambient temperature and calcination. The obtained SiW12@Co3O4 exhibited a highly inherent peroxidase-like activity and excellent stability. Kinetic studies demonstrated that the synthesized SiW12@Co3O4 had a strong binding affinity to 3,3',5,5'-tetramethylbenzidine (TMB), stronger than HRP had. Specifically, the peroxidase-like activity of SiW12@Co3O4 in an aqueous solution was well maintained after incubation at an elevated temperature, at an extreme pH and for a long time. A SiW12@Co3O4-based method was further developed for H2O2 and one-pot glucose detection with good sensitivity and reliability. The facile synthesis approach is expected to facilitate the practical use of metal-organic frameworks and their derivatives as enzyme mimics in the future.


Assuntos
Glucose/análise , Peróxido de Hidrogênio/análise , Estruturas Metalorgânicas/química , Benzidinas/química , Colorimetria/métodos , Glucose/química , Glucose Oxidase/química , Peróxido de Hidrogênio/química , Limite de Detecção , Estruturas Metalorgânicas/síntese química , Oxirredução , Peroxidase/química
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