Reactive Oxygen Species (ROS) Responsive Polymers for Biomedical Applications

Reactive oxygen species (ROS) play important roles in cell signaling pathways, while increased production of ROS may disrupt cellular homeostasis, giving rise to oxidative stress and a series of diseases. Utilizing these cell‐generated species as triggers for selective tuning polymer structures and properties represents a promising methodology for disease diagnosis and treatment. Recently, significant progress has been made in fabricating biomaterials including nanoparticles and macroscopic networks to interact with this dynamic physiological condition. These ROS‐responsive platforms have shown potential in a range of biomedical applications, such as cancer targeted drug delivery systems, cell therapy platforms for inflammation related disease, and so on.

     

聚合物的表面光接枝改性

本文总结了利用紫外光接枝改性聚合物表面的研究进展，对接枝方法，接枝证明。接枝结构、实验条件对接枝的影响以及其广泛的应用几个方面进行了介绍。     

Recent Developments in the Surface Modification of Polymers

Summary. Selected trends and scientific achievements in the surface modification of polymers are reported. In this context, both UV-light triggered free radical polymerization-based techniques relevant to industrial processes and ring-opening metathesis polymerization-based chemistry, relevant for the manufacture of specialty materials, are addressed.     

Surface Modification of Banana Fibers by DBD Plasma Treatment

Banana fibers, an environmentally friendly raw material freely available, were physically modified by atmospheric dielectric barrier discharge (DBD) plasma treatment of different dosages. The influence of the plasma treatment applied on the banana fibers was performed considering the mechanical properties, wettability, chemical composition and surface morphology. These properties were evaluated by tensile tests, static and dynamic contact angle, Fourier transform infrared spectroscopy, energy dispersive spectroscopy, X-ray diffractometry, conductivity and pH of aqueous extract, differential scanning calorimetry and scanning electron microscopy images. We compare untreated and treated fibers with three different DBD plasma dosages. The results of this study showed considerable modifications in banana fibers when these are submitted to plasma treatment.     

Recent Progress in the Biological Applications of Reactive Oxygen Species-Responsive Polymers

Abstract

Responsive polymeric materials that are sensitive to biological stimuli including temperature, pH, enzymes, or redox conditions have attracted research interest in recent years. Among these, reactive oxygen species (ROS)-responsive polymers are particularly appealing because of the special role of ROS in living organisms. ROS are the indicator and cause of certain diseases, and they are also important signaling molecules. ROS-responsive polymers could possess the following functions: drug carriers, ROS probes, or medications for certain ROS-related diseases. In this review, we analyze the progress about ROS-responsive polymers made in recent years and predict the future trends of ROS-responsive polymers from the above mentioned perspectives. Due to the limited scope of this review, some older articles are not covered here and are left for more comprehensive reviews.     

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.     

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.     

活性氧响应型抗肿瘤前药研究进展

活性氧(ROS)在机体信号转导和代谢中起着至关重要的作用,而ROS水平的升高与多种病变(癌症和炎症等)息息相关,基于肿瘤组织高水平ROS开发的肿瘤特异杀伤性前药策略,在增强药效和药物选择性方面提供了一种新颖的方法.本综述介绍了目前用于构建抗肿瘤前药的ROS敏感键:芳基硼酸/酯、烷基硫/硒醚、硫缩酮、过氧草酸酯、氨基丙烯酸酯、噻唑烷酮和α-酮酰胺等,并且详叙了基于这些敏感键设计的前药在抗肿瘤方向上的应用,同时探讨了现有ROS响应型前药系统的研究进展和局限性,并对未来的研究方向进行了展望.     

检测活性氧物种的氧杂蒽类光学探针的研究进展

活性氧物种在维持生物体的生理功能方面发挥着重要的作用.高于正常水平的活性氧物种会损伤蛋白质、DNA等生物分子,进而导致疾病.因此,活性氧物种的高选择性、高灵敏度检测研究对疾病的预防、诊断和治疗均具有重要意义.荧光探针因具有分析灵敏度高、样品时空分辨能力强等特点,已在该方面获得了广泛的应用.其中,具有发射波长长,光稳定性好,荧光量子产率高等优点的氧杂蒽类荧光探针已成为检测活性氧物种的研究热点.本论文主要总结了近五年来应用于活性氧物种检测的氧杂蒽类荧光探针的研究进展与成像分析,归纳了不同活性氧物种的识别单元,并展望了此类探针的发展趋势与应用前景.     

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...     

用于检测生物体系中线粒体活性氧的荧光探针

In addition to being the energy powerhouse of the cell, mitochondria are an important source of reactive oxygen species (ROS) during the process of molecular oxygen metabolism. Mitochondrial ROS are closely associated with normal physiological functions as well as human diseases, and participate in cell signaling, nucleic acid and protein damage, and oxidative stress induction. However, the complicated interplay between mitochondrial ROS and the cellular pathological state has not been fully elucidated. It is expected that research on the mitochondrial ROS undertaking in the molecular pathogenesis of human diseases would benefit from development of efficient tools for the detection of these ROS. In recent years, an increasing number of fluorescent probes for mitochondrial ROS with high sensitivity and selectivity have been developed. Here, we present a review of the recent advances in small molecular fluorescent probes for selective detection of ROS inside the mitochondria. In this review, the design, synthesis, characteristics, and applications of the published fluorescent probes for mitochondrial ROS are discussed in detail.     

Spatial and Surface Design of Porous Coordination Polymers

A significant challenge in the development of porous coordination polymers (PCP's), beyond control of pore size, is control of the shape and chemical nature of the pores. This short review presents some compounds that illustrate these features and general approaches to their preparation.     

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。     

Anticancer Aminoferrocene Derivatives Inducing Production of Mitochondrial Reactive Oxygen Species

Elevated levels of reactive oxygen species (ROS) and deficient mitochondria are two weak points of cancer cells. Their simultaneous targeting is a valid therapeutic strategy to design highly potent anticancer drugs. The remaining challenge is to limit the drug effects to cancer cells without affecting normal ones. We have previously developed three aminoferrocene (AF)-based derivatives, which are activated in the presence of elevated levels of ROS present in cancer cells with formation of electron-rich compounds able to generate ROS and reduce mitochondrial membrane potential (MMP). All of them exhibit important drawbacks including either low efficacy or high unspecific toxicity that prevents their application in vivo up to date. Herein we describe unusual AF-derivatives lacking these drawbacks. These compounds act via an alternative mechanism: they are chemically stable in the presence of ROS, generate mitochondrial ROS in cancer cells, but not normal cells and exhibit anticancer effect in vivo.     

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.     

Concurrent Reactive Oxygen Species Generation and Aneuploidy Induction Contribute to Thymoquinone Anticancer Activity

Thymoquinone (TQ) is the main biologically active constituent of Nigella sativa. Many studies have confirmed its anticancer actions. Herein, we investigated the different anticancer activities of, and considered resistance mechanisms to, TQ. MTT and clonogenic data showed TQ’s ability to suppress breast MDA-MB-468 and T-47D proliferation at lower concentrations compared to other cancer and non-transformed cell lines tested (GI₅₀ values ≤ 1.5 µM). Flow-cytometric analyses revealed that TQ consistently induced MDA-MB-468 and T-47D cell-cycle perturbation, specifically inducing pre-G1 populations. In comparison, less sensitive breast MCF-7 and colon HCT-116 cells exhibited only transient increases in pre-G1 events. Annexin V/PI staining confirmed apoptosis induction in MDA-MB-468 and HCT-116 cells, which was continuous in the former and transient in the latter. Experiments revealed the role of reactive oxygen species (ROS) generation and aneuploidy induction in MDA-MB-468 cells within the first 24 h of treatment. The ROS-scavenger NAD(P)H dehydrogenase (quinone 1) (NQO1; DT-diaphorase) and glutathione (GSH) were implicated in resistance to TQ. Indeed, western blot analyses showed that NQO1 is expressed in all cell lines in this study, except those most sensitive to TQ-MDA-MB-468 and T-47D. Moreover, TQ treatment increased NQO1 expression in HCT-116 in a concentration-dependent fashion. Measurement of GSH activity in MDA-MB-468 and HCT-116 cells found that GSH is similarly active in both cell lines. Furthermore, GSH depletion rendered these cells more sensitive to TQ’s antiproliferative actions. Therefore, to bypass putative inactivation of the TQ semiquinone metabolite, the benzylamine analogue was designed and synthesised following modification of TQ’s carbon-3 atom. However, the structural modification negatively impacted potency against MDA-MB-468 cells. In conclusion, we disclose the following: (i) The anticancer activity of TQ may be a consequence of ROS generation and aneuploidy; (ii) Early GSH depletion could substantially enhance TQ’s anticancer activity; (iii) Benzylamine substitution at TQ’s carbon-3 failed to enhance anticancer activity.     

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。     

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。     

量子点的聚合物表面修饰及其应用

量子点作为新型纳米发光材料备受关注,但由于光学稳定性和生物相容性的问题而在实际应用上受限。聚合物对量子点的修饰能够提供量子点合成的有效支撑基质,而且还可以改善量子点的稳定性和单分散性,进而可以拓展量子点应用于化学、物理以及生物学领域。基于聚合物修饰量子点的优势,本文简述了聚合物表面修饰量子点的方法、合成路线、步骤、特点以及发展现状。其中,双亲分子涂敷的量子点可以改善量子点的水溶性;多基配体包裹的量子点更具有稳定性和功能性;末端功能化聚合物表面修饰的量子点则可以合成更为先进功能的材料;胶封树枝状定域量子点具有单分散和优越发光特性。同时,还综述了各种表面修饰方法的最新研究进展,存在问题以及应用发展趋势。