Nanotechnology for Electroanalytical Biosensors of Reactive Oxygen and Nitrogen Species

Over the past several decades, nanotechnology has contributed to the progress of biomedicine, biomarker discovery, and the development of highly sensitive electroanalytical / electrochemical biosensors for in vitro and in vivo monitoring, and quantification of oxidative and nitrosative stress markers like reactive oxygen species (ROS) and reactive nitrogen species (RNS). A major source of ROS and RNS is oxidative stress in cells, which can cause many human diseases, including cancer. Therefore, the detection of local concentrations of ROS (e. g. superoxide anion radical; O₂^•−) and RNS (e. g. nitric oxide radical; NO^• and its metabolites) released from biological systems is increasingly important and needs a sophisticated detection strategy to monitor ROS and RNS in vitro and in vivo. In this review, we discuss the nanomaterials‐based ROS and RNS biosensors utilizing electrochemical techniques with emphasis on their biomedical applications.     

生物系统活性氧及其反应与损伤致病作用

从量子化学概念评述活性氧毒性结构原理 ,总结生物系统活性氧基本反应 ,绘制出活性氧转化关系图 ,由图分析活性氧产生、转化、损伤作用和对其清除防御 ,以及这些反应与疾病和衰老的关系。简介这一领域的进展和动向。     

Influence of the Outer Electrode Material on Ozone Generation in Corona Discharges

The effect of the outer electrode material on negative corona discharge current and the process of ozone formation have been studied in coaxial cylindrical system of electrodes fed by dry oxygen. Three materials (brass, duralumin, stainless steel) were tested in experiments. The probability coefficient of ozone decomposition was found be slightly higher compared with known data. The coefficient of probability of ozone decomposition is decreasing with the time of exposition of the metal surface to mixture of oxygen and ozone. The effect of the electrode material on the current voltage characteristic of the discharge was marginal. In contrast to this at average energy density η higher than 10 J/cm³ the ozone concentration is affected by material of the outer electrode. A strong influence of the temperature of metal electrode on the probability coefficient of ozone decomposition was illustrated from the decrease of the ozone production.     

活性氧捕获材料的研究进展

生命从呼吸中获得氧气, 氧气再进一步在线粒体中将糖类等氧化得到能量, 提供给生命过程使用. 然而在氧化过程中, 会生成高度活泼的活性氧. 当体内控制失衡的时候, 它的浓度会大大增加, 发生氧化应激, 对机体产生不可逆的破坏, 引起衰老、肿瘤、心血管以及神经性疾病等. 抵抗活性氧的核心物质是抗氧化物, 它的存在使氧化应激受到控制, 从而保护机体免遭伤害. 本文对国内外近年来在活性氧自由基捕获方面的研究进行系统的综述, 通过梳理, 提出研究的金字塔型三级结构. 设计抗氧化物大分子与无机纳米粒子复合的纳米杂化自由基捕获器可以一方面解决无机纳米粒子的毒性问题, 另一方面还可以赋予纳米粒子额外的功能. 期待这篇综述文章能为改性纳米粒子捕捉活性氧提供一些有益思路, 为功能高分子材料与杂化纳米技术在生物医学领域的探索提供借鉴.     

基于扫描电化学显微镜技术研究细胞实时释放ROS

本研究利用扫描电化学显微镜(SECM)技术考察了十四烷酰佛波醇乙酸酯(PMA)刺激肺癌细胞(A549)活性氧物种(ROS)的实时变化。以过氧化氢(H_2O_2)为目标检测物,获得了细胞氧化应激的电化学响应图像。以氯化六氨基合钌(Ru(NH_3)_6Cl_3)为体系介质,利用电流负反馈技术获得细胞形貌的清晰图像,同时优化获得探针与基底之间的最佳检测距离。将探针电位设定为过氧化氢的还原电位(-0.65 V)时,通过电流成像图可观察到ROS实时释放,实现了A549细胞被PMA即时刺激时ROS释放的实时检测。扩大扫描区域,获得了不同个体细胞ROS释放的SECM图像,实现了SECM对ROS信号的实时捕捉及再现性。结果显示:PMA可破坏细胞含氧物种的动态平衡,诱发细胞产生氧化应激响应。将探针放置在细胞ROS释放位点,检测其电流随时间变化,可观察到电流随时间呈现波动状态,推测ROS的胞外释放是一个动态的脉动过程。     

Detection of Reactive Oxygen and Nitrogen Species by Upconversion Nanoparticle-Based Near-Infrared Nanoprobes: Recent Progress and Perspectives

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are essential oxidative metabolites of organisms, which are closely related to physiological, pathological and pharmacological processes. The accurate detection of ROS/RNS is important for the understanding of biological processes, monitoring of pharmacological effects, and predicting the course of disease. The recently developed NIR nanoprobes based on upconversion nanoparticles (UCNPs) hold great prospects in sensitive and deep-tissue detection of ROS/RNS, and considerable progress has been achieved so far. In this review, we systematically summarize the up-to-date advances of UCNPs-based near-infrared (NIR) probes for ROS/RNS sensing, and the potential challenges and perspectives for further research are also highlighted. We envision that such a research field will have a bright future for modern biomedical applications.     

铁卟啉与活性氮的相互作用

在活性氮(RNS)与蛋白质的相互作用过程中,含铁卟啉蛋白/铁卟啉可以催化RNS转化为惰性的NO3-,阻止蛋白质的硝化;同时,含铁卟啉蛋白/铁卟啉也可通过高价铁氧化物及.NO2的产生来加速蛋白质的硝化。生理条件下,血红蛋白、肌红蛋白等含铁卟啉蛋白可清除多余的RNS;氧化应激条件下,过氧化物酶等含铁卟啉蛋白可以不同的方式催化加速RNS对蛋白质的硝化。     

An Enzyme-Mimicking Single-Atom Catalyst as an Efficient Multiple Reactive Oxygen and Nitrogen Species Scavenger for Sepsis Management

Sepsis, characterized by immoderate production of multiple reactive oxygen and nitrogen species (RONS), causes high morbidity and mortality. Despite progress made with nanozymes, efficient antioxidant therapy to eliminate these RONS remains challenging, owing largely to the specificity and low activity of exploited nanozymes. Herein, an enzyme-mimicking single-atom catalyst, Co/PMCS, features atomically dispersed coordinatively unsaturated active Co-porphyrin centers, which can rapidly obliterate multiple RONS to alleviate sepsis. Co/PMCS can eliminate O₂^.− and H₂O₂ by mimicking superoxide dismutase, catalase, and glutathione peroxidase, while removing ^.OH via the oxidative-reduction cycle, with markedly higher activity than nanozymes. It can also scavenge ^.NO through formation of a nitrosyl–metal complex. Eventually, it can reduce proinflammatory cytokine levels, protect organs from damage, and confer a distinct survival advantage to the infected sepsis mice.     

酶振荡"探针"研究生物活性氧的新进展

评述了研究生物活性氧的意义和方法，简要概述了时空振荡反应中酶振荡的某些研究进展，提出了以酶振荡“探针”研究生物活性氧的新方法。     

活性氧物种在光催化选择性氧化中的研究进展

活性氧物种(ROS)在光催化选择性氧化过程中起着至关重要的作用.研究人员通过调控材料结构,优化其ROS产生的种类及浓度,可以有效提高相应光催化选择氧化反应的效率,为实现未来绿色工业搭桥铺路.本文将对常见的ROS产生过程进行解读,同时阐明其在各个催化反应中的作用机制,最后介绍不同ROS的检测和验证方法.本文可为光催化反应...     

Production of Reactive Oxygen Species and Application for NOx Control

Current gas ionization discharge techniques used in the removal of NOx from waste gases require large plasma sources, have high energy consumption, and may feature low NOx removal rates. We develop a system to generate reactive oxygen species through a strong ionization discharge, which is injected into a flow of simulated waste gas. The relative proportions and temperatures of input gases were controlled and the rate of consumption by reactive species was monitored. HNO₃ oxidization products of NOx were also collected and measured. The molar ratio of reactive oxygen species to NO was optimized to improve the rate of NOx removal. A input gas temperature of 58–60 °C was also found to be optimal. The O₂ volume fraction has almost no influence on NOx removal, while H₂O volume fractions above 6 %, gave rise to NOx removal rates of 97.2 %. The present study addresses disadvantages of current gas ionization discharge and requires no catalyst, reducing agent or oxidant.     

微流控芯片毛细管电泳法检测细胞内活性氧与细胞凋亡关系

建立了微流控芯片毛细管电泳激光诱导荧光同时测定细胞内活性氧和凋亡信号的方法。先用AlexaFluor488 annexin V细胞凋亡试剂盒标记细胞凋亡的外翻磷脂酰丝氨酸,再用双氢罗丹明123(DHR123)标记细胞内活性氧,用PBS将细胞调整为终密度1.2×106cells/mL的细胞悬液。细胞群经反复冻融法破碎后,以20 mmol/L硼砂(pH 9.2)作电泳缓冲溶液,分离电压1.2 kV,进样时间60 s,1 min内可完成活性氧和细胞凋亡信号的同时测定。方法简单、快速,细胞内活性氧和DHR123的反应产物(Rh123)在0.5～3μmol/L浓度范围内线性关系良好,相关系数(r)为0.998,检出限(S/N=3)为0.058μmol/L,可用于细胞内活性氧的定量分析。测得HepG2肝癌细胞活性氧含量为0.16μmol/L,被阿霉素诱导凋亡后,细胞内活性氧含量升高至1.77μmol/L。     

Comparison of Mechanisms of N-Nitrosation and N-Nitration of Ammonia and Dimethylamine by Reactive Nitrogen Oxygen Species: A Theoretical Study

Reactive nitrogen oxygen species(RNOS) implicate damage in biological systems,especially leading to inflammation,neurodegenerative and cardiovascular diseases,and cancer by altering the functions of biomolecules through the N-nitrosation and N-nitration reactions.The mechanisms of N-nitrosation and N-nitration reactions of ammonia and dimethylamine by RNOS,i.e.,N2O3,N2O4,N2O5 and ONOOH,were investigated at the CBS-QB3 level of theory.The computational results indicate that the N-nitrosation reaction prefers a concerted mechanism,in which a H-abstraction and ON-addition occur simultaneously,whereas a stepwise mechanism(also called a free radical mechanism) is more favorable for most nitrating agents in the N-nitration reaction,where NO2 first abstracts a hydrogen atom from the nitrogen of amines and then the induced intermediate reacts with NO2 once more to form the nitration products.However,the concerted pathway is still a feasible process for some nitrating agents such as N2O5.In addition,the relationship between the structures of different RNOS and their nitrosating or nitrating abilities was also investigated.     

Aggregation-Induced Generation of Reactive Oxygen Species: Mechanism and Photosensitizer Construction

Luminogens with aggregation-induced emission (AIEgens) have been widely applied in the field of photodynamic therapy. Among them, aggregation-induced emission photosensitizers (AIE–PSs) are demonstrated with high capability in fluorescence and photoacoustic bimodal imaging, as well as in fluorescence imaging-guided photodynamic therapy. They not only improve diagnosis accuracy but also provide an efficient theranostic platform to accelerate preclinical translation as well. In this short review, we divide AIE–PSs into three categories. Through the analysis of such classification and construction methods, it will be helpful for scientists to further develop various types of AIE–PSs with superior performance.     

Synthesis, and Investigation of the Reactive Oxygen Species of a Novel Cyclicpeptide-2,6-dimethoxyhydroquinone-3- mercaptoacetic Acid Conjugate

In the previous paper, we had reported the synthesis of a novel series of linear peptide conjugates of the cytotoxic agent 2,6-dimethoxyhydroquinone-3-mercaptoacetic acid1 (DMQ-MA). In this paper, we choose the cyclic peptides over linear peptides as drug carriers. Our preference for this study is based on the following reason: cyclic peptides, with their N- and C- terminals blocked, are more hydrophobic and would pass through the cell membrane more readily than liner peptides2. Also cyc…     

The Contribution of Reactive Oxygen Species to the Photobleaching of Organic Fluorophores

Photoexcitation of fluorophores commonly used for biological imaging applications generates reactive oxygen species (ROS) which can cause bleaching of the fluorophore and damage to the biological system under investigation. In this study, we show that singlet oxygen contributes relatively little to Cy5 and ATTO 647N photobleaching at low concentrations in aqueous solution. We also show that Cy5 generates significantly less ROS when covalently linked to the protective agents, cyclooctatetraene (COT), nitrobenzyl alcohol (NBA) or Trolox. Such fluorophores exhibit enhanced photostability both in bulk solutions and in single‐molecule fluorescence measurements. While the fluorophores ATTO 647N and ATTO 655 showed greater photostability than Cy5 and the protective–agent‐linked Cy5 derivatives investigated here, both of ATTO 647N and ATTO 655 generated singlet oxygen and hydroxyl radicals at relatively rapid rates, suggesting that they may be substantially more phototoxic than Cy5 and its derivatives.     

Investigation of Cold Atmospheric Plasma-Activated Water for the Dental Unit Waterline System Contamination and Safety Evaluation in Vitro

The disinfection of the inner surface of a medical device has long been a challenge for the central sterile supply departments. Dental unit waterline system (DUWLs) foster the attachment of microorganisms and development of biofilm, which lead to continuous contamination of the outlet water from dental units; this contamination may be responsible for a potential risk of infection due to the exposure of patients and medical staff. The present study investigated the disinfection effects of cold atmospheric plasma-activated water (CAPAW) on DUWLs using a model of 5-day-old Enterococcus faecalis biofilm. The results showed that the colony-forming unit was reduced from 10⁷ to 0 after 5 min of treatment. The physicochemical properties of CAPAW were evaluated, including the pH value, oxidation reduction potential, and NO radical. The results showed that the inactivation mechanisms were mainly triggered by the reactive oxygen/nitrogen species. Additionally, CAPAW had a metal corrosion rate same as that of deionized water. We conclude that CAPAW can be applied as an appropriate alternative disinfectant against biofilm contamination of DUWLs.     

Reactive Oxygen,Nitrogen, and Sulfur Species (RONSS)‐Responsive Polymersomes for Triggered Drug Release

Reactive oxygen, nitrogen, and sulfur species (RONSS) are cross‐reacting and involved in a myriad of physiological and pathological processes. Similar to acidic pH, overexpressed enzymes, and other specific stimuli found in pathological microenvironments, RONSS are recognized as a category of emerging triggering events and have been employed to design activatable theranostic nanomaterials. In this regard, a plethora of RONSS‐responsive nanovectors including polymeric micelles and vesicles (also referred to as polymersomes) are constructed. In comparison with micelles, polymersomes comprising aqueous interiors enclosed by hydrophobic membranes show intriguing applications in synergistic delivery of both hydrophobic and hydrophilic drugs, nanoreactors, and artificial organelles. This feature article focuses on the recent developments in the fabrication of RONSS‐responsive polymersomes and their potential biomedical applications in terms of triggered drug delivery.

     

Study on Sensitization from Reactive Oxygen Species for Electrochemiluminescence of Luminol in Neutral Medium

In this paper, the sensitization on electrochemiluminescent (ECL) reaction of luminol from reactive oxygen species (ROSs) in neutral medium was studied. The powerful sensitization from ROSs even related with organics and organisms were examined under selected conditions which were suitable for biochemical analysis. The results indicated that whether the enhancers were dissolved in solutions or immobilized on the surface of conventional electrodes, stronger ECL intensity of luminol could be obtained. Enhanced ECL helped to provide groundwork for the detection of biomolecules for which would further enhance or quench the ECL signals. The technique may provide new means in a variety of fields such as clinical diagnostics, immunological analysis and environmental monitoring due to its simplicity and high efficiency.