生物正交剪切反应及其应用

生物正交反应在化学生物学的研究中发挥着越来越重要的作用.传统的生物正交反应以新化学键生成的连接反应为主,其在实现生物分子的“标记”、“示踪”和“捕捉”等研究中发挥着重要作用.近年来,一类新兴的反应类型--以化学键断裂为基础的生物正交剪切反应逐渐发展起来,并在分子的“释放”、“激活”和“操控”等方面得到了越来越广泛的应用.本文首先重点介绍了生物正交剪切反应,总结了这些反应的特点、适用范围和已经实现的用途.随后通过具体的例子介绍了这些反应在化学生物学中的应用,包括小分子前药的激活、蛋白质功能的调控、细胞的工程化等.最后文章对生物正交剪切反应的发展趋势进行了展望.     

模块化生物无机化学教学模式的构建与实践

围绕提高学生专业能力这一核心需求，结合课堂教学实践，遵循“前沿导读+专题研讨+项目实训”的专业课程模块化理念，以“结构-性质-活性关系”为线索，对生物无机化学教学内容进行模块化处理与再加工。在实际教学中将问题导向学习和案例教学相结合。实践表明，绝大部分学生认为模块化教学模式更有利于对理论知识的认识，且参加项目实训的积极性很高。     

基于裂开型核酸适配体的液晶生物传感检测三磷酸腺苷

利用“适配体-目标分子-适配体”的“三明治”夹心方式构建液晶生物传感检测三磷酸腺苷(ATP). 将ATP核酸适配体片段作为捕获探针固定在经TEA/DMOAP混合组装膜修饰的玻片基底表面, 当ATP存在时, 裂开的两部分核酸适配体与ATP结合形成双链结构, 有效诱导液晶分子取向发生变化从而引起光学信号的亮度及颜色发生变化, 实现对ATP的检测, 该方法在ATP浓度为10 nmol/L时仍可观测到明显的光学信号变化. 这种“适配体-目标分子-适配体”的“三明治”夹心式液晶生物传感方法具有无需标记, 操作简单等特点, 在快速检测小分子等物质领域中有广泛的应用前景.     

以“位构性”模型建构和学科能力发展的必修“原子结构 元素周期律”教学设计和实践*

在高中必修阶段“原子结构 元素周期律”主题已有研究的基础上,将“位构性”系统模型与学科能力活动任务相结合,提出了本研究的理论框架,进行了单元整体的教学设计并实施。通过预设学生的表现水平,设计各课时的评价任务,过程性地诊断学生在各个课时中“位构性”模型建构与学科能力的发展水平,描述学生在本章学习过程中的发展变化,促进了学生“证据推理与模型认知”等核心素养的发展。最后,归纳出以“位构性”模型建构和学科能力发展的“原子结构 元素周期律”在教学实践中的有效策略。以期能够对日后开展“原子结构 元素周期律”主题的教学设计与实践能够提供参考和建议。     

基于核酸适体的电化学生物传感器*

核酸适体是一类体外筛选的、可与目标分子高效、高特异亲合的RNA或DNA寡核苷酸片段,与常规识别分子（如抗体等）相比,核酸适体作为一类新型识别分子具有明显特色和优势,已被广泛应用于生物传感等分子识别和应用研究领域。本文就基于核酸适体的电化学生物传感器（标记型和非标记型）的近期进展作简要评述,包括适体简介、标记型（“信号衰减”型、“信号增强”型、酶标记型和纳米粒子标记型）和非标记型电化学适体生物传感器等内容。     

仿衣壳结构的巨大中空超分子纳米容器的多组分自组装构筑及其功能

在自然界病毒衣壳及笼状蛋白质大分子结构的启发下,运用V型双齿桥连吡啶配体和具有平面四方构型的Pd²⁺离子的溶液配位自组装,一系列具有M_nL_2n经验分子式的多组分巨大中空“纳米容器”型超分子结构被成功构筑。通过在配体内外引入官能团的策略,可以简单地实现衣壳骨架结构的内外功能化。内功能化后的“纳米容器”具有特殊的高密度相,不仅可以实现对不同类型客体分子的包裹,而且可以作为“纳米反应器”实现尺寸均一可控纳米粒子的原位合成以及小分子的催化转化。外功能化的核壳结构则可以对寡肽、DNA等生物分子具有特定的识别作用。本文对此类“纳米容器”型超分子的设计原理、自组装合成与表征、以及功能化应用等方面进行了综述。     

从“精灵”到催化“多面手”的钴元素

钴因德语中“Kobold”一词而得名,从最早发现时的“精灵”到现在已成为催化“多面手”。回顾了钴元素的发现与得名过程以及钴元素在化学学科发展过程中的重要历史意义,介绍了钴元素作为催化剂的活性中心在清洁能源和绿色合成方面的相关应用。     

化工类专业课教学中开展爱国主义教育的探索*——以“节能减排与国家利益”专题教学为例

在“课程思政”背景下,如何在化工类专业课教学中开展爱国主义教育,是一大挑战。将节能减排所涉及的专业知识作为载体,引入“碳排放”议题作为思政素材,引导学生运用专业知识来解读该议题,将爱国主义元素“无声”地融入专业课教学中。通过解析美国在该议题背后的真实目的和我国的应对策略,激发学生的爱国热情,并使之认识到党在维护国家发展利益方面的决心和能力;通过探寻新中国不同时期的重大历史事件与“碳排放”走势的关联性,使学生深刻认识中国共产党带领中国人民选择了一条正确的道路。本专题教学将专业知识与“思政”元素深度融合,实现了爱国、爱党和爱社会主义3者的统一,对同行教育工作者具有一定的借鉴意义。     

日本初中理科教科书中“粒子的存在”内容组织与呈现特征

从“主要观念”“核心内容”“重要问题”“情境活动”等4个方面自上而下对日本的《新科学》教科书中“粒子的存在”相关内容的组织与呈现进行分析，发现其具有注重内容结构化和学生认识进阶性，以科学探究活动引领，“粒子模型”显性化等特征。     

“笑气”:让人欢喜让人忧*——“笑气”的功过及其滥用问题的思考

我国青少年“笑气”滥用问题日趋严峻,引发社会关注。介绍了“笑气”的简要历史、制备方法、结构与性质、重要应用、滥用原因及危害等,期望引导青少年全面了解“笑气”,科学使用“笑气”,提早构筑起心理防线,自觉抵制“笑气”滥用。     

Biological applications of carbon dots

Carbon dots (C-dots), since their first discovery in 2004 by Scrivens et al. during purification of single-walled carbon nanotubes, have gradually become a rising star in the fluorescent nanoparticles family, due to their strong fluorescence, resistance to photobleaching, low toxicity, along with their abundant and inexpensive nature. In the past decade, the procedures for preparing C-dots have become increasingly versatile and facile, and their applications are being extended to a growing number of fields. In this review, we focused on introducing the biological applications of C-dots, hoping to expedite their translation to the clinic.     

光控水凝胶的构筑及在生物医药领域的应用

水凝胶由于具有优越的保水性、良好的生物相容性和可降解性,被认为是最接近人体组织的生物医用材料。通过构建环境敏感水凝胶可以高度拟合生物组织的微环境,实现其在组织工程与再生医学领域的应用。由于光具有非物理接触和时空分辨等优势,利用光调控技术可实现水凝胶微环境的精确构筑与调控。本文重点介绍了近年来光控水凝胶的构筑,以及在生物医学和材料领域的应用进展。     

Bactericidal block copolymer micelles

Block copolymer micelles with bactericidal properties were designed to deactivate pathogens such as E. coli bacteria. The micelles of PS‐b‐PAA and PS‐b‐P4VP block copolymers were loaded with biocides TCMTB or TCN up to 20 or 30 wt.‐%, depending on the type of antibacterial agent. Bacteria were exposed to loaded micelles and bacterial deactivation was evaluated. The micelles loaded with TCN are bactericidal; bacteria are killed in less than two minutes of exposure. The most likely interpretation of the data is that the biocide is transferred to the bacteria by repeated micelle/bacteria contacts, and not via the solution.

     

(Coixan polysaccharide)-graft-polyethylenimine folate for tumor-targeted gene delivery

CP-PEI-FA was prepared as an effective vector for in vitro and in vivo tumor-targeted gene delivery. The structures of the polymers were characterized, and their DNA condensation capability, particle sizes, zeta potentials, cytotoxicity and in vitro/in vivo transfection were examined. The cytotoxicity of CP-PEI-FA was significantly lower than that of PEI 25 kDa and close to that of PEI 1200. The in vitro transfection of CP-PEI-FA was tested in C6 and HeLa cells (FR-positive cells) and A549 cells (FR-negative cells). CP-PEI-FA showed a high targeting specificity and good gene transfection efficiency in FR-positive cells. These results indicate that CP-PEI-FA is a safe and effective polyplex-forming agent for both in vitro and in vivo transfection of plasmid DNA.     

Optical applications of quantum dots in biological system

This review presents a simple introduction on the unique properties and general synthesis of quantum dots (QDs) in which we lay emphasis on the optical applications in the biological system. The detection of biological molecules such as DNA, protein and enzyme, the cell-based analysis and in vivo animal imaging are mainly discussed.     

Effect of Head Size in Head‐Tail‐Type Polycations on their in vitro Performances as Nonviral Gene Vectors

Three kinds of head‐tail‐type block copolymers composed of polyamidoamine (PAMAM) dendron heads and poly(L ‐lysine) (PLL) tail blocks (PAMAM dendron‐PLL), having PAMAM dendrons with different generations (G2.5‐PLL, G3.5‐PLL and G4.5‐PLL) were synthesized. Some of the dendron heads were located at polyplex surface, and G2.5‐PLL and G3.5‐PLL could form small polyplexes (less than 150 nm in size). G2.5‐PLL and G3.5‐PLL polyplexes were taken up into the cells more effectively. PAMAM dendron‐PLL that had a larger dendron head could show a more‐effective buffering effect. The in vitro performance of the PAMAM dendron‐PLL polyplexes was controlled by the balance of cellular uptake and endosomal escape by a buffering effect.

     

Synthesis and properties of a well‐defined glycopolymer via living radical polymerization

A well‐defined glycopolymer was synthesized to investigate its properties. The glycopolymer was obtained with a narrow polydispersity by nitroxide‐mediated radical polymerization of styrene carrying acetylated lactose and by the subsequent deprotection. The cylindrical structure and helical conformation of the polymer were measured by circular dichroism (CD) spectra. The affinities of the polymers towards lectins depended on the degree of polymerization (DP), and the polymers with higher DP showed stronger affinity. Copyright © 2007 John Wiley & Sons, Ltd.     

Reconstructing the differentiation niche of embryonic stem cells using biomaterials

The biochemical cues and topographical architecture of the extracellular environment extensively influence ES cell fate. The microenvironment surrounding the developing embryo presents these instructive cues in a complex and interactive manner in order to guide cell fate decisions. Current stem cell research aims to reconstruct this multifaceted embryonic niche to recapitulate development in vitro. This review focuses on 2D and 3D differentiation niches created from natural and synthetic biomaterials to guide the differentiation of ES cells toward specific lineages. Biomaterials engineered to present specific physical constraints are also reviewed for their role in differentiation.     

量子点在生物检测中的应用

过去十几年里,量子点从材料科学到生命科学、从基础研究到实际应用都开展了广泛的研究。 量子点在生物成像、光治疗、药物/基因转运、太阳能电池等领域均具有广泛的应用。 通过调节量子点的表面性质,实现量子点与细胞相互作用的可控性是一个关键的问题。 伴随着量子点潜在毒性问题的产生,纳米毒性成为纳米材料安全性评估的重要指标,并且受到科学家们的高度关注。 本文综述了量子点的特性、细胞生物学应用及在生物医药领域相关的细胞毒性研究,并展望了量子点的未来发展趋势。     

纳米粒子的分类合成及其在生物领域的应用

纳米粒子是当今最受关注也是最常报道的一类纳米材料,尺寸处于纳米级别是纳米粒子的突出特点,这赋予其在化学、光学、电学和磁学等方面优于传统块体材料的独特性能,因而纳米粒子越来越受到人们的重视,并广泛应用于很多领域,尤其是生物医药领域。本文围绕可生物应用的纳米粒子,从组成以及结构的角度着手,将纳米粒子分为有机纳米粒子、无机纳米粒子以及有机/无机杂化纳米粒子。同时结合近三年国内外关于各类纳米粒子新颖的合成报道,分别阐述了上述不同种类纳米粒子所具有的适合生物应用的物理和化学方面的特征,并针对不同类别的新型纳米粒子,着重描述了其具体合成方法和潜在的生物应用。最后,简单介绍了纳米粒子在生命科学这一领域的具体应用实例,如刺激响应感应器、生物特异性标记及基因药物载体等,并展望了纳米粒子在该领域的长远发展。