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.

     

Smart Molecularly Imprinted Polymers: Recent Developments and Applications

The use of the molecular imprinting technique to produce polymers with high specificity for a given “molecular template” has undergone a rapid and expansive evolution since the inception of the idea over half a century ago. It was only a matter of time before the seemingly inevitable “marriage” of this concept with another modern research obsession, the generation of “smart” polymers, capable of reacting quickly, accurately and reproducibly to changes in their environment. Many advances have since been made, concerning the quality and diversity of these systems and polymers responsive to temperature, pH and a host of other environmental cues now exist. This article provides a succinct overview of the process and outcomes of “smart” molecular imprinting, followed by a detailed assessment of recent developments and applications in such field.

     

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.     

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.     

基于胆汁酸的刺激响应聚合物

刺激响应聚合物是当今材料科学研究的热点之一。其在外界刺激下,自身的物理或者化学性质发生变化产生响应,在药物可控释放、生物传感器、催化、吸附分离等方面有广阔的应用。胆汁酸是天然的甾类生物分子,其分子结构中含有羟基和羧基等官能团,容易进行化学修饰,且具有双亲性和一定的刚性。在聚合物中引入胆汁酸分子,能够从结构和功能两个方面丰富刺激响应高分子的研究。一方面,胆汁酸及修饰的胆汁酸既可以作为单体直接聚合,也可以被连接到含有一定官能团的聚合物上,由此可以得到以胆汁酸作为主链、侧基、端基,以及胆汁酸作为星形聚合物的核等多种聚合物结构。另一方面,胆汁酸的引入不仅可以提高聚合物的生物相容性,有效地赋予聚合物胆汁酸结构的独特性质,而且可以用于构建具有一定刺激响应功能的组装结构,进而应用于形状记忆、手性分离、药物载体等材料中。本文综述了基于胆汁酸的刺激响应聚合物近年来的相关工作,从基于胆汁酸的刺激响应聚合物的分子设计和结构构筑出发,结合其性质和应用进行论述,也对该领域的改进和发展提出展望。     

光致活性氧淬灭方法检测生物抗氧化剂动力学模型分析

以TiO2纳米颗粒光催化反应为模型,研究了反应过程中的活性氧( ROS)产生以及活性氧淬灭的反应动力学模型。对苯二甲酸分子与体系中的光催化反应产生的OH·反应,生成具有荧光性质的2-羟基对苯二甲酸( lex=315 nm,lem=425 nm),因此对苯二甲酸作为氧化探针分子与体系中的生物抗氧化剂( AOs)分子竞争与ROS的反应,根据体系的荧光、反应时间以及AOs的浓度建立了AOs淬灭ROS的反应动力学模型。根据此模型推导AOs清除ROS的动力学常数,发现常见的生物抗氧化剂的抗氧化活性大小顺序为：硫辛酸、没食子酸、谷胱甘肽、尿酸、维生素C、维生素E、水溶性维生素E和胆红素。     

提高聚合物共混相容性的反应性聚合物

反应性聚合物作为聚合物共混的增容剂受到越来越广泛的重视。本文论述了该类反应性聚合物的制备，分类及研究开发现状，并结合实例讨论了其增容作用效果。     

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.     

Fluorescence Evaluation of Scavenging Efficiency of Antioxidants Against Reactive Oxygen Species (ROS) in Cigarette Smoke

Cigarette smoke can cause cellular oxidative stress that contributes to various adverse health effects associated with smoke exposure, partially due to reactive oxygen species (ROS) present in cigarette smoke. Reduction of abundant ROS in the cigarette mainstream smoke (MSS) is of importance for human health. In this work, a simple, rapid, and reliable fluorescence evaluation of scavenging efficiency of antioxidants as potential filter additives against ROS in cigarette smoke is reported. This method was based on the combination of model glass reactor and a fluorescence assay of ROS in cigarette smoke using dihydrorhodamine 6 G (DHR-6 G). The antioxidant was added into a glass reactor attached to cigarette filter, which simplified the preparation of combined filter containing additives. The ROS scavenging efficiency of antioxidants was then determined using spectrofluorimetry by the change in fluorescence intensity of whole smoke-bubbled solutions before and after addition of antioxidants into the glass reactor. The proposed method was successfully applied to the determination of ROS scavenging efficiency of several potential additives, such as tert-butylhydroquinone (TBHQ), vitamin C, β-carotene, grape seed extract, and Ginkgo biloba extract. Moreover, the relationship between MSS ROS scavenging efficiency and antioxidant activities (DPPH radicals scavenging efficiency and Fe²⁺ reducing power) of these compounds was also investigated.     

SERS纳米探针对电刺激过程中细胞内产生活性氧的检测

电刺激是用于细胞内紊乱电活动引起疾病的一类重要治疗方式. 在电刺激过程中是否会诱导细胞内活性氧(ROS)水平的改变, 以及常规抗氧化抑制药物与电刺激治疗同时运用带来的影响, 目前尚未有相关研究. 本文设计了一种具有较好生物相容性的金/银核壳纳米棒表面增强拉曼(SERS)活性探针, 用于电刺激过程中细胞内产生ROS的检测. 将该探针与细胞共孵育, 使其内化入细胞, 对细胞进行不同时间的电刺激, 利用拉曼光谱对SERS探针的信号进行检测. 实验结果表明, 随着电刺激时间的延长, SERS信号减弱, 说明细胞内产生ROS的量明显增加. 该传感机制是利用ROS能刻蚀金/银核壳纳米棒的银壳, 从而使其变薄引起SERS信号减弱. 抗坏血酸(AA)和谷胱甘肽(GSH)两种抗氧化抑制剂类药物与电刺激同时运用时, 可观察到它们会对电刺激过程产生的ROS有清除作用. 该研究发展了一类用于细胞内ROS检测的光谱方法, 也为异常的氧化应激和肿瘤治疗过程中的组合用药提供了建议.     

超氧化物歧化酶化学模拟的新进展

超氧化物歧化酶在生物体内特异性地催化超氧离子自由基（O2˙ˉ）的歧化反应, 具有抗氧化、抗癌症、抗炎症等重要生理学作用。近年来,超氧化物歧化酶的化学模拟倍受关注并引发人们极广泛的研究兴趣。本文系统综述了超氧化物歧化酶模拟物在设计合成及应用上的新近研究进展。     

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.     

酸分解高分子的新进展

本文综述了80年代酸分解高分子的进展,并对其作了详细分类。以其不同的结构特征阐明了它们的酸解机理。本文还对酸解高分子用于成像材料、特别是化学增幅抗蚀剂的前景作了展望。     

Fast Optical Healing of Crystalline Polymers Enabled by Gold Nanoparticles

A general method for very fast and efficient optical healing of crystalline polymers is reported. By loading a very small amount of gold nanoparticles (AuNPs) in either poly(ethylene oxide) (T_m ≈ 63 °C) or low‐density polyethylene (T_m ≈ 103 °C), the heat released upon surface plasmon resonance (SPR) absorption of 532 nm light by AuNPs can melt crystallites in the interfacial region of two polymer pieces brought into contact; and the subsequent recrystallization of polymer chains on cooling merges the two pieces into one. The fracture strength of such repaired sample can reach the level of the undamaged polymer after 10 s laser exposure. Moreover, in addition to an ability of long‐distance remote and spatially selective healing, the optical method also works for polymer samples immersed in water.

     

Influence of Reactive Diluent on UV-curing of Acrylate Terminated Hyperbranched Polymers

A Aeries of hydroxylic hyperbranched polymers were derived from 2,2-bis (methylol) propionic acid and tris (methylol) propane reacted with acrylic acid to various extents. The obtained acrylated hyperbranched polymers alone or with a monofunctional diluent, isobornylene acrylate(IBOA) were further cured by UV radiation. The cured films based on the modified polymers alone all demonstrated poor mechanical properties due to their high network densities and low moving ability of polymer chains. For the composite systems, the cured films demonstrated improved mechanical properties due to the low network densities and high chain moving ability. With more IBOA included in the systems, acrylate groups can react to a higher extent during the curing process.     

稀土离子(La3+, Gd3+, Yb3+)对线粒体产生活性氧的影响

研究了稀土离子对分离的线粒体产生活性氧(ROS)的影响. 采用荧光光度法跟踪线粒体内H2O2生成的动力学, 发现三种稀土离子(La3+, Gd3+, Yb3+)均能降低线粒体H2O2的生成; 用黄嘌呤-黄嘌呤氧化酶体系进一步证明稀土对超氧阴离子(·O-2)存在清除作用, 而对H2O2无清除作用; 测定了稀土对线粒体ROS代谢酶(谷胱甘肽过氧化物酶和超氧化物歧化酶)的活性影响. 结果表明, 三种稀土离子对线粒体谷胱甘肽过氧化物酶的活性基本没有影响, 而Gd3+和Yb3+稀土离子能明显抑制线粒体超氧化物歧化酶的活性.     

In Vivo Electrochemical Biosensors for Reactive Oxygen Species Detection: A Mini-Review

Due to the significance of reactive oxygen species (ROS) in numerous physiological processes including pathogen response, apoptosis, and induction of defense genes, various methods have been developed for their quantitative analysis. However, the conventional methods using exogenous tracers lack the capability to conduct real-time in vivo measurements. The electrochemical biosensors have shown their potentials for in vivo applications with the rapid and reagentless detection processes. In this article, electrochemical biosensors that are capable of making in vivo ROS detections are reviewed. The different configurations of these biosensors with corresponding strategies to enhance sensitivity and selectivity are discussed in detail. With further studies to promote the biosensor performance, these devices promise to provide more facile ways for ROS research in life sciences.     

反应性聚合物微凝胶的合成及应用

反应性聚合物微凝胶是一种具有反应活性,分子内交联的高分子。它具有优良的加工性能,涂膜的力学性能及耐久性也十分优异,主要应用于制备高档涂料或对涂料进行改性,本文着重介绍了反应性聚合物微凝胶的合成方法及其在涂料改性方面的应用。     

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.

     

Plasma and Polymers: Recent Progress and Trends

Plasma-enhanced synthesis and modification of polymers is a field that continues to expand and become increasingly more sophisticated. The highly reactive processing environments afforded by the inherently dynamic nature of plasma media are often superior to ambient or thermal environments, offering substantial advantages over other processing methods. The fluxes of energy and matter toward the surface enable rapid and efficient processing, whereas the charged nature of plasma-generated particles provides a means for their control. The range of materials that can be treated by plasmas is incredibly broad, spanning pure polymers, polymer-metal, polymer-wood, polymer-nanocarbon composites, and others. In this review, we briefly outline some of the recent examples of the state-of-the-art in the plasma-based polymer treatment and functionalization techniques.