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1.
Chem Commun (Camb) ; 60(42): 5546-5549, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38700121

RESUMO

Airborne nanoplastics can enter alveolar cells and trigger intracellular oxidative stress primarily. Herein, taking advantage of the high electrochemical resolution of SiC@Pt nanoelectrodes, we achieved the quantitative discrimination of the major ROS/RNS within A549 cells, disclosed the sources of their precursors, and observed that the NO (RNS precursor) level significantly increased, whereas O2˙- (ROS precursor) remained relatively stable during the nanoplastics exposure. This establishes that iNOS or mitochondrion-targeted treatment may be a preventive or therapeutic strategy for nanoplastic-induced lung injury.


Assuntos
Técnicas Eletroquímicas , Espécies Reativas de Nitrogênio , Espécies Reativas de Oxigênio , Humanos , Espécies Reativas de Oxigênio/metabolismo , Células A549 , Espécies Reativas de Nitrogênio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Eletrodos
2.
Analyst ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38757525

RESUMO

ATP plays a crucial role in cell energy supply, so the quantification of intracellular ATP levels is particularly important for understanding many physio-pathological processes. The intracellular quantification of this non-electroactive molecule can be realized using aptamer-modified nanoelectrodes, but is hindered by the limited quantity of modification and electroactive tags on the nanosized electrodes. Herein, we developed a simple but effective electrochemical signal amplification strategy for intracellular ATP detection, which replaces the regular ATP aptamer-linked ferrocene monomer with a polymer, thus greatly magnifying the amounts of electrochemical reporters linked to one chain of the aptamer and enhancing the signals. This ferrocene polymer-ATP aptamer was further immobilized onto Au nanowire electrodes (SiC@C@Au NWEs) to achieve accurate quantification of intracellular ATP in single cells, presenting high electrochemical signal output and high specificity. This work not only provides a powerful tool for quantifying intracellular ATP but also offers a simple and versatile strategy for electrochemical signal amplification in the detection of broader non-electroactive molecules involved in different kinds of intracellular physiological processes.

3.
Inorg Chem ; 63(13): 6067-6074, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38489513

RESUMO

The first examples of alkali metal selenite sulfates, namely, Na8(SeO3)(SO4)3 (1), Na2(H2SeO3)(SO4) (2), and K4(H2SeO3)(HSO4)2(SO4) (3), were successfully synthesized by hydrothermal reactions. Their structures display three different zero-dimensional configurations composed of isolated sulfate tetrahedra and selenite groups separated by alkali metals. Na8(SeO3)(SO4)3 (1) features a noncentrosymmetric structure, while Na2(H2SeO3)(SO4) (2) and K4(H2SeO3)(HSO4)2(SO4) (3) are centrosymmetric. Powder second-harmonic-generation measurements revealed that Na8(SeO3)(SO4)3 (1) shows a phase-matchable SHG intensity about 1.2 times that of KDP. UV-vis-NIR diffuse reflectance spectroscopic analysis indicated that Na8(SeO3)(SO4)3 (1) has a short UV cutoff edge and a large optical band gap, which makes it a possible UV nonlinear optical material. Theoretical calculations revealed that the birefringence of Na8(SeO3)(SO4)3 (1) is 0.041 at 532 nm, which is suitable for phase-matching condition. This work provides a good experimental foundation for the exploration of new UV nonlinear crystals in an alkali metal selenite sulfate system.

4.
Nat Nanotechnol ; 19(4): 524-533, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38172432

RESUMO

Exposure to widely used inert fibrous nanomaterials (for example, glass fibres or carbon nanotubes) may result in asbestos-like lung pathologies, becoming an important environmental and health concern. However, the origin of the pathogenesis of such fibres has not yet been clearly established. Here we report an electrochemical nanosensor that is used to monitor and quantitatively characterize the flux and dynamics of reactive species release during the frustrated phagocytosis of glass nanofibres by single macrophages. We show the existence of an intense prolonged release of reactive oxygen and nitrogen species by single macrophages near their phagocytic cups. This continued massive leakage of reactive oxygen and nitrogen species damages peripheral cells and eventually translates into chronic inflammation and lung injury, as seen during in vitro co-culture and in vivo experiments.


Assuntos
Nanofibras , Nanotubos de Carbono , Oxigênio , Nanotubos de Carbono/química , Fagocitose , Macrófagos , Espécies Reativas de Oxigênio
5.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1007206

RESUMO

Objective@#To explore the relationship between lifestyle and myopia and construct Nomogram model to predict myopia risk among primary school students in Tianjin, so as to provide a scientific basis for precision myopia prevention and control.@*Methods@#From April to July of 2022, a census method was used to conduct vision testing and lifestyle related questionnaires among 373 180 primary school students in 15 districts of Tianjin. The relationship between lifestyle and myopia was analyzed by the multivariate Logistic regression, and a nomogram prediction model was constructed to predict myopia risk.@*Results@#The detection rate of myopia among primary school students in Tianjin was 37.6%. The results of the multivariate Logistic regression showed that daily outdoor activity time of 1-2 h ( OR =0.94) and >2 h ( OR =0.84), time of using daily electronic devices of >2 h ( OR =1.03), daily paper materials reading and writing time of 1-2 h ( OR =1.02) and >2 h ( OR =1.09), weekly fresh vegetable intake of 2-6 times ( OR =0.93) and ≥7 times ( OR =0.88) were statistically correlated with myopia ( P <0.01). The Nomogram prediction model showed that the factors associated with myopia were grade, family history of myopia, gender, daily outdoor activity time, weekly frequency of fresh vegetable intake, daily paper materials reading and writing time, and time of using daily electronic devices time.@*Conclusions@#The lifestyle of primary school students in Tianjin is associated with myopia. The constructed nomogram model could provide a scientific basis for identifying key intervention populations for myopia prevention and taking targeted prevention and control measures.

6.
Angew Chem Int Ed Engl ; 62(51): e202313612, 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-37909054

RESUMO

The glutathione (GSH) system is one of the most powerful intracellular antioxidant systems for the elimination of reactive oxygen species (ROS) and maintaining cellular redox homeostasis. However, the rapid kinetics information (at the millisecond to the second level) during the dynamic antioxidation process of the GSH system remains unclear. As such, we specifically developed a novel dual-wire nanosensor (DWNS) that can selectively and synchronously measure the levels of GSH and ROS with high temporal resolution, and applied it to monitor the transient ROS generation as well as the rapid antioxidation process of the GSH system in individual cancer cells. These measurements revealed that the glutathione peroxidase (GPx) in the GSH system is rapidly initiated against ROS burst in a sub-second time scale, but the elimination process is short-lived, ending after a few seconds, while some ROS are still present in the cells. This study is expected to open new perspectives for understanding the GSH antioxidant system and studying some redox imbalance-related physiological.


Assuntos
Antioxidantes , Estresse Oxidativo , Antioxidantes/metabolismo , Espécies Reativas de Oxigênio , Glutationa/metabolismo , Oxirredução
7.
Proc Natl Acad Sci U S A ; 120(19): e2219994120, 2023 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-37126689

RESUMO

Glutamate (Glu) is the major excitatory transmitter in the nervous system. Impairment of its vesicular release by ß-amyloid (Aß) oligomers is thought to participate in pathological processes leading to Alzheimer's disease. However, it remains unclear whether soluble Aß42 oligomers affect intravesicular amounts of Glu or their release in the brain, or both. Measurements made in this work on single Glu varicosities with an amperometric nanowire Glu biosensor revealed that soluble Aß42 oligomers first caused a dramatic increase in vesicular Glu storage and stimulation-induced release, accompanied by a high level of parallel spontaneous exocytosis, ultimately resulting in the depletion of intravesicular Glu content and greatly reduced release. Molecular biology tools and mouse models of Aß amyloidosis have further established that the transient hyperexcitation observed during the primary pathological stage is mediated by an altered behavior of VGLUT1 responsible for transporting Glu into synaptic vesicles. Thereafter, an overexpression of Vps10p-tail-interactor-1a, a protein that maintains spontaneous release of neurotransmitters by selective interaction with t-SNAREs, resulted in a depletion of intravesicular Glu content, triggering advanced-stage neuronal malfunction. These findings are expected to open perspectives for remediating Aß42-induced neuronal hyperactivity and neuronal degeneration.


Assuntos
Doença de Alzheimer , Ácido Glutâmico , Camundongos , Animais , Ácido Glutâmico/metabolismo , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Neurônios/metabolismo , Encéfalo/metabolismo , Fragmentos de Peptídeos/metabolismo
8.
Chem Commun (Camb) ; 59(13): 1773-1776, 2023 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-36722385

RESUMO

Intracellular H2S plays an important regulatory role in cell metabolism. The limited sensing materials and severe sensor passivation hinder its quantification. We functionalized conductive nanowires with MoS2 and quercetin in a large-scale manner, developed single nanowire sensors with excellent electrocatalytic and anti-poisoning performance, and achieved the accurate quantification of H2S within single cells.


Assuntos
Sulfeto de Hidrogênio , Nanofios , Sulfeto de Hidrogênio/metabolismo
9.
Biosens Bioelectron ; 220: 114899, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36399941

RESUMO

The study of subcellular targets and biochemical processes within a living cell is valuable for biological and medical research. Secretory vesicles, one such important intracellular target, are nanoscale lipid structures that are capable of storage, transport, and secretion of, for example, neurotransmitters, hormones, proteins or waste products. Vesicles play an essential role in intercellular communication systems, as they facilitate the release of chemical messaging agents. If deregulated, these communication processes can be a central part in the pathogenesis of some neurodegenerative diseases or diabetes. Generally, due to their nanometer size and intracellular location, the analysis of single vesicles and their content is a great challenge. It requires sensitive techniques, micro/nanoscale tools and sensitive instruments with extreme spatio-temporal resolution. This review focuses on electrochemical sensors to study the biochemistry and quantification of messenger molecules and other species (e.g., reactive oxygen and nitrogen species) stored in organelles, providing new trends and developments in this field. Furthermore, we review the effect of the chemical environment of single cells (e.g., treatment with chemicals, drugs, lipids, and ions) on regulation of the physical and chemical properties of vesicles. Finally, unsolved challenges of and perspectives on vesicle electroanalysis are discussed.


Assuntos
Pesquisa Biomédica , Técnicas Biossensoriais , Comunicação Celular , Nitrogênio , Organelas
10.
Biosens Bioelectron ; 222: 114928, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36450163

RESUMO

Reactive oxygen species (ROS) and nicotinamide adenine dinucleotide (NADH) are important intracellular redox-active molecules involved in various pathological processes including inflammation, neurodegenerative diseases, and cancer. However, the fast dynamic changes and mutual regulatory kinetic relationship between intracellular ROS and NADH in these biological processes are still hard to simultaneously investigate. A dual-channel nanowire electrode (DC-NWE) integrating two conductive nanowires, one functionalized with platinum nanoparticles and the other with conductive polymer, was nanofabricated for the selective and simultaneous real-time monitoring of intracellular ROS and NADH release by mitochondria in single living MCF-7 tumoral cells stimulated by resveratrol. The production of ROS was observed to occur tenths of a second before the release of NADH, a significant new piece of information suggesting a mechanism of action of resveratrol. Beyond the importance of the specific data gathered in this study, this work established the feasibility of simultaneously monitoring multiple species and analyzing their kinetics relationships over sub-second time scales thanks to dual-channel nanowire electrodes. It is believed that this concept and its associated nanoelectrochemical tools might benefit to a deeper understanding of mutual regulatory relationship between intracellular crucial molecular markers during physiological and pathological processes as well as for evaluating medical treatments.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , NAD/química , Espécies Reativas de Oxigênio , Cinética , Resveratrol , Platina , Oxirredução
11.
Int J Gen Med ; 15: 8603-8615, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36545244

RESUMO

Objective: In the direction of evaluating the current status of outcome indicators and control group selection in randomized controlled studies of Chinese herbal compounding (such as Sini plus Renshen Decoction, Jianpifuzhengfang, Bufei Jianzhong Decoction, etc) for cancer-caused fatigue and to provide a reference for clinical studies of Chinese herbal compounding for cancer-caused fatigue. Methods: Randomized controlled studies of Chinese herbal medicine for cancer-caused fatigue in the midst of 2012 and 2022 were searched in CNKI, PubMed, and EMBASE databases on the China Knowledge Network, and the literature was screened using NoteExpress. Two researchers independently conducted the literature review, and then the studies that met the criteria were grouped and analyzed adopting qualitative analysis of outcome indicators and control groups. Results: A total of 70 randomized controlled studies that met the requirements were included, and after doing statistical analysis, it can draw to the conclusion that the risk of bias in the included studies was high; at the same time, the TCM evidence score scale, objective indicators, and safety indicators were underutilized; additionally, there were no uniform standards for the fatigue scale, and the selection of control groups lacked balance and consistency. Conclusion: The outcome indicators of TCM compound treatment of cancer-caused fatigue should be on the basis of the principle of "diagnosis and treatment" in TCM, the proportion of objective indicators should be exaggerated, as well as the interventions in the control group should be unified.

12.
World J Clin Cases ; 10(34): 12671-12677, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36579087

RESUMO

BACKGROUND: Bronchogenic cysts are cystic masses caused by congenital abnormal development of the respiratory system, and usually occur in the pulmonary parenchyma or mediastinum. CASE SUMMARY: A rare case of a bronchogenic cyst discovered in the abdominal cavity of a 35-year-old man is reported. Physical examination found a space-occupying lesion in the patient's abdomen for 4 d. Laparoscopic exploration found the cyst tightly adhered to the stomach and its peripheral blood vessels; therefore, intraoperative laparotomy was performed. The cystic mass was resected en bloc with an Endo-GIA stapler. The final postoperative pathological diagnosis confirmed an abdominal bronchogenic cyst. CONCLUSION: This is a rare case of a bronchogenic cyst that was discovered within the abdominal cavity of a male patient. The cyst is easily confused with or misdiagnosed as other lesions. Therefore, it is necessary to distinguish abdominal bronchogenic cyst from gastrointestinal stromal tumor, Meckel's diverticulum, enteric duplication cyst, or lymphangioma. Although computer tomography and magnetic resonance imaging were the primary diagnostic approaches, endoscopic ultrasound-guided fine-needle aspiration could assist with clarification of the cytological or histopathological diagnosis before surgery.

13.
Angew Chem Int Ed Engl ; 61(43): e202210224, 2022 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-36074259

RESUMO

Interfacing biological tissues with electronic sensors offers the exciting opportunity to accurately investigate multiple biological processes. Accurate signal collection and application are the foundation of these measurements, but a long-term issue is the signal distortion resulting from the interface gap. The height of the gap is the key characteristic needed to evaluate or model the distortion, but it is difficult to measure. By integrating a pair of nanopores at the electronic sensor plane and measuring the ion conductance between them, we developed a versatile and straightforward strategy to realize the direct cooperative evaluation of the gap height during exocytotic release from adrenal gland tissues. The signaling distortion of this gap has been theoretically evaluated and shows almost no influence on the amperometric recording of exocytosis in a classic "semi-artificial synapse" configuration. This strategy should benefit research concerning various bio/chemical/machine interfaces.


Assuntos
Nanoporos , Eletrônica
14.
World J Clin Cases ; 9(32): 9869-9877, 2021 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-34877325

RESUMO

BACKGROUND: At present, colorectal cancer is routinely treated with adjuvant radiotherapy and chemotherapy postoperatively. The adverse effects (AEs) of chemotherapy usually interrupt the treatment of chemotherapy. Traditional Chinese medicine (TCM) has demonstrated great potential in improving patients' clinical symptoms, regulating the immune function, improving the life quality, and reducing the AEs of chemotherapy. AIM: To observe the clinical efficacy of Yiqi Jianpi anti-cancer prescription combined with chemotherapy in patients with colorectal cancer after operation. METHODS: Data from patients diagnosed with colorectal cancer between January 2019 and February 2021 were collected from Liaoning Cancer Hospital and Institute and the Second Affiliated Hospital of Liaoning University of Traditional Chinese Medicine. Patients receiving the chemotherapy regimen of capecitabine plus oxaliplatin (CAPOX) after radical resection of colorectal cancer were prospectively collected and randomly divided into an experimental group and a control group. The experimental group was given Yiqi Jianpi anti-cancer prescription combined with the CAPOX regimen, while the control group was given the CAPOX regimen alone. After six cycles of chemotherapy, the scores of TCM symptoms, Karnofsky performance scale (KPS) score, levels of T-cell subsets, and AEs after chemotherapy of the two groups were compared. RESULTS: A total of 70 patients were randomly divided into either an experimental group (n = 35, no dropout) or a control group (n = 33, with 2 dropouts). Compared with the control group, the experimental group improved significantly (P < 0.05) in scores of TCM symptoms, KPS score, levels of T-cell subsets, and AEs of chemotherapy. CONCLUSION: Yiqi Jianpi anti-cancer prescription can effectively improve spleen deficiency, regulate the immune function, and alleviate the AEs of chemotherapy, so as to improve the life quality of patients with good therapeutic effects and application prospect in clinical practice.

15.
Chem Sci ; 12(30): 10273-10278, 2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34447531

RESUMO

The release of the cargo from soft vesicles, an essential process for chemical delivery, is mediated by multiple factors. Among them, the regulation by the interaction between the chemical cargo species and the vesicular membrane, widely existing in all vesicles, has not been investigated to date. Yet, these interactions hold the potential to complicate the release process. We used liposomes loaded with different monoamines, dopamine (DA) and serotonin (5-HT), to simulate vesicular release and to monitor the dynamics of chemical release from isolated vesicles during vesicle impact electrochemical cytometry (VIEC). The release of DA from liposomes presents a longer release time compared to 5-HT. Modelling the release time showed that DA filled vesicles had a higher percentage of events where the time for the peak fall was better fit to a double exponential (DblExp) decay function, suggesting multiple kinetic steps in the release. By fitting to a desorption-release model, where the transmitters adsorbed to the vesicle membrane, the dissociation rates of DA and 5-HT from the liposome membrane were estimated. DA has a lower desorption rate constant, which leads to slower DA release than that observed for 5-HT, whereas there is little difference in pore size. The alteration of vesicular release dynamics due to the interaction between the chemical cargo and vesicle membrane lipids provides an important mechanism to regulate vesicular release in chemical and physiological processes. It is highly possible that this introduces a fundamental chemical regulation difference between transmitters during exocytosis.

16.
Nurse Educ Today ; 98: 104718, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33454659

RESUMO

BACKGROUND: Recently, mindfulness interventions have been extensively applied in the field of nursing education. However, no consensus has been reached on whether these interventions can reduce anxiety and depression in nursing students. OBJECTIVE: This meta-analysis was designed to determine the effect of mindfulness interventions on levels of depression, anxiety, stress and mindfulness for nursing students. DESIGN: Meta-analysis of randomized controlled trials. METHODS: The following Chinese and English databases were searched for relevant articles: Pubmed, Embase, Cochrane library, Web of Science, CNKI (China National Knowledge Infrastructure) and Wanfang. The search encompassed the establishment of these databases up until January 2020. Two reviewers separately entered the data into Review Manager Software 5.3. RESULTS: A total of 10 randomized controlled trials (RCTs) were reviewed. It was found that mindfulness interventions significantly lowered levels of depression (SMD = -0.42, 95% CI:-0.56 to -0.28, P < 0.001), anxiety (SMD = -0.32, 95% CI:-0.47 to -0.17, P < 0.001) and stress (SMD = -0.50, 95% CI:-0.65 to -0.35, P < 0.001) in nursing students. Furthermore, the interventions raised levels of mindfulness in this group (SMD = 0.54, 95% CI:0.33-0.75, P < 0.001). CONCLUSIONS: Mindfulness interventions can significantly reduce nursing students' negative emotions, helping them to manage their stress and anxiety. College nursing educators should consider adopting mindfulness interventions in nursing education to promote the mental health of students.


Assuntos
Atenção Plena , Estudantes de Enfermagem , Ansiedade/prevenção & controle , China , Depressão/prevenção & controle , Humanos
17.
J Am Chem Soc ; 142(9): 4093-4097, 2020 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-32069039

RESUMO

We have developed the means to simultaneously measure the physical size and count catecholamine molecules in individual nanometer transmitter vesicles. This is done by combining resistive pulse (RP) measurements in a nanopore pipet and vesicle impact electrochemical cytometry (VIEC) at an electrode as the vesicle exits the nanopore. Analysis of freshly isolated bovine adrenal vesicles shows that the size and internal catecholamine concentration of vesicles varies with the occurrence of a dense core inside the vesicles. These results might benefit the understanding about the vesicles maturation, especially involving the "sorting by retention" process and concentration increase of intravesicular catecholamine. The methodology is applicable to understanding soft nanoparticle collisions on electrodes, vesicles in exocytosis and phagocytosis, intracellular vesicle transport, and analysis of electroactive drugs in exosomes.


Assuntos
Catecolaminas/análise , Grânulos Cromafim/química , Técnicas Eletroquímicas/métodos , Nanoporos , Animais , Bovinos , Técnicas Eletroquímicas/instrumentação , Eletrodos , Tamanho da Partícula
18.
Small ; 15(48): e1901787, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31183973

RESUMO

Mitochondria are believed to be the major source of intracellular reactive oxygen species (ROS). However, in situ, real-time and quantitative monitoring of ROS release from mitochondria that are present in their cytosolic environment remains a great challenge. In this work, a platinized SiC@C nanowire electrode is placed into a single cell for in situ detection of ROS signals from intracellular mitochondria, and antineoplastic agent (paclitaxel) induced ROS production is successfully recorded. Further investigations indicate that complex IV (cytochrome c oxidase, COX) is the principal site for ROS generation, and significantly more ROS are generated from mitochondria in cancer cells than that from normal cells. This work provides an effective approach to directly monitor intracellular mitochondria by nanowire electrodes, and consequently obtains important physiological evidence on antineoplastic agent-induced ROS generation, which will be of great benefit for better understanding of chemotherapy at subcellular levels.


Assuntos
Eletroquímica/métodos , Mitocôndrias/metabolismo , Paclitaxel/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Linhagem Celular Tumoral , Eletrodos , Humanos , Camundongos , Mitocôndrias/efeitos dos fármacos , Células NIH 3T3 , Nanofios/química
19.
Nanoscale ; 11(22): 10702-10708, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31140521

RESUMO

Glucose metabolism plays an important role in cell energy supply, and quantitative detection of the intracellular glucose level is particularly important for understanding many physiological processes. Glucose electrochemical sensors are widely used for blood and extracellular glucose detection. However, intracellular glucose detection cannot be achieved by these sensors owing to their large size and consequent low spatial resolution. Herein, we developed a single nanowire glucose sensor for electrochemical detection of intracellular glucose by depositing Pt nanoparticles (Pt NPs) on a SiC@C nanowire and further immobilizing glucose oxidase (GOD) thereon. Glucose was converted by GOD to an electroactive product H2O2 which was further electro-catalyzed by Pt NPs. The glucose nanowire sensor is endowed with a high sensitivity, high spatial-temporal resolution and enzyme specificity due to its nanoscale size and enzymatic reaction. This allows the real-time monitoring of the intracellular glucose level, and the increase of the intracellular glucose level induced by a novel potential hypoglycemic agent, reinforcing its potential application in lowering the blood glucose level. This work provides a versatile method for the construction of enzyme-modified nanosensors to electrochemically detect intracellular non-electroactive molecules, which is of great benefit for physiological and pathological studies.


Assuntos
Técnicas Biossensoriais , Enzimas Imobilizadas/química , Glucose Oxidase/química , Glucose/análise , Nanopartículas Metálicas/química , Nanofios/química , Platina/química , Animais , Bovinos , Linhagem Celular , Células Endoteliais da Veia Umbilical Humana , Humanos
20.
Angew Chem Int Ed Engl ; 58(23): 7753-7756, 2019 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-30969456

RESUMO

The existence of a homeostatic mechanism regulating reactive oxygen/nitrogen species (ROS/RNS) amounts inside phagolysosomes has been invoked to account for the efficiency of this process but could not be unambiguously documented. Now, intracellular electrochemical analysis with platinized nanowire electrodes (Pt-NWEs) allowed monitoring ROS/RNS effluxes with sub-millisecond resolution from individual phagolysosomes impacting onto the electrode inserted inside a living macrophage. This shows for the first time that the consumption of ROS/RNS by their oxidation at the nanoelectrode surface stimulates the production of significant ROS/RNS amounts inside phagolysosomes. These results establish the existence of the long-postulated ROS/RNS homeostasis and allows its kinetics and efficiency to be quantified. ROS/RNS concentrations may then be maintained at sufficiently high levels for sustaining proper pathogen digestion rates without endangering the macrophage internal structures.


Assuntos
Técnicas Eletroquímicas/métodos , Eletrodos , Homeostase , Macrófagos/metabolismo , Fagossomos/metabolismo , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Células Cultivadas , Macrófagos/citologia , Camundongos , Oxirredução
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