多肽纳米管

环状多肽是构成多肽纳米管的主要子结构,它的结构形式和骨架分子构象直接影响多肽纳米管的特性。作为有特殊电子和光学性质的多肽纳米管,它在化学、生物、材料和医学等方面有潜在的应用。本文就自组装多肽纳米管的结构和应用作了介绍。     

自组装金属有机纳米管模板法制备高分子纳米管

高分子纳米管(PNT)是一类具有中空管状结构的高分子纳米材料, 模板法是制备管状高分子纳米材料的有效方法. 本研究以自组装金属有机纳米管(MONT)为模板, 杈状多元胺和多元羧酸为前体分子, 利用杈状多元胺与MONT表面的铜离子配位络合, 在MONT表面上形成包覆层, 再与同样具有杈状结构的多元羧酸活化酯进行交联反应后, 去除掉内部的自组装模板, 从而制得具有良好水分散性的PNT. 利用扫描电子显微镜(SEM)、扫描透射电子显微镜(STEM)、差示扫描量热仪(DSC)、X射线衍射(XRD)和漫反射傅立叶变换红外光谱(DRIFTS)对PNT的表面形貌、组成和结构进行了表征. 结果表明, 当多元胺用量为MONT用量的0.4摩尔当量时, 交联产物的成管率最高, 达80%以上, 纳米管的长度大多为500 nm~3 μm、内径为60~100 nm、外径80~120 nm.     

基于杯芳烃主体的分子自组装研究进展

分子自组装是超分子化学最重要的研究内容之一. 杯芳烃作为继冠醚、环糊精之后的第三代人工合成受体分子已在分子自组装研究方面取得了重要进展并显示了广泛的应用前景. 主要综述杯芳烃衍生物通过氢键、金属诱导配位、π-π作用、疏水作用等非共价键弱相互作用力在溶液状态、固态和界面的分子自组装方面的研究进展.     

自组装有机纳米功能材料

大量研究发现自组装材料可以具有导电、电致发光、光－电转换等优异功能。由简单到复杂的自发组装过程无处不在, 在此基础上已经制备出了功能化染料膜、有机/无机杂化结构的组装膜、传感器、太阳能电池、光通讯元件等功能膜材料和器件。通过分子自组装形成共价键合的、具有稳定和结构可控的材料结构在生物系统中是非常重要的,如今它已日渐成为非生物学研究的焦点,有理由相信它最终将成为一门重要的技术,帮助我们制造大量复杂有用的功能材料。本文介绍了有机自组装材料的结构、自组装方法及其在应用方面取得的一些进展。     

环境响应性多肽自组装研究进展

分子自组装广泛存在于自然界中,参与生物体的各项生命活动,从而确保生物体相关生理功能的实现和生化反应的有序进行.多肽自组装作为分子自组装的重要组成部分,其良好的生物相容性为构建具有重要应用价值的生物医用材料提供了新的思路.本文总结了多肽自组装过程中主要的驱动作用力;简述了多肽自组装形成的主要结构;详细介绍了自组装过程中环境变化,包括pH、温度、离子强度、特殊离子、氧化还原态以及光照等,对于环境响应性多肽自组装结构和性质的影响;并且阐述了多肽自组装生物材料的应用方向和前景,希望为该领域的进一步研究提供参考.     

超分子聚集体构筑单元的分子设计及其自组装研究进展

超分子聚集体因有着丰富的形貌和多样化的功能,并具有良好的可调控性,而备受广大超分子科学家的关注。不同结构的超分子聚集体在新材料开发、药物传输、生物成像和医疗卫生等领域均有着极其重要的研究价值和应用前景。基于在不同领域中超分子聚集体的应用特点,其自组装构筑单元的设计方法也有着诸多的选择,如何高效地设计并制备有价值的超分子体系构筑单元已经成为超分子化学研究的一个重要课题。基于超分子聚集体自组装过程的影响因素,对超分子聚集体构筑单元的主要设计方法和思路进行了总结和分析,为后续不同体系超分子聚集体构筑单元的设计及其自组装过程的相关研究提供重要的参考。     

多肽分子自组装

源于自然界中广泛存在的蛋白质自组装现象,近年来多肽的自组装逐渐成为材料学和生物医学等领域的研究热点.通过合理调控多肽的分子结构以及改变外界的环境,多肽分子可以利用氢键、疏水性作用、π-π堆积作用等非共价键力自发或触发地自组装形成形态与结构特异的组装体.由于多肽自身具有良好的生物相容性和可控的降解性能,利用多肽自组装技术构建的各种功能性材料在药物控制释放、组织工程支架材料以及生物矿化等领域内有着巨大的应用前景.本文总结了近年来多肽自组装研究的进展,介绍了多肽自组装技术常见的几种结构模型,概括了多肽自组装的机理,并进一步阐述多肽自组装形成的组装体形态及其在材料学和生物医学等领域里的应用.     

基于氢键的自组装超分子体系

氢键自组装超分子是超分子体系中相对较新颖和引人注意的领域,它在化学和生物体系中占据非常重要的位置。本文主要介绍目前文献报道的一系列由不同氢键缔合方式形成的自组装超分子。     

多肽类自组装纳米材料对抗细菌耐药的研究进展

细菌感染,尤其是耐药性细菌感染,是人类健康的巨大威胁之一.多肽类药物具有生物相容性较好、不易引起细菌产生耐药等特点,在耐药细菌感染的治疗中起着重要的作用.其中,由多肽自组装纳米材料制备的仿生纳米结构在抗耐药菌感染方面展现出独特的优势.多肽自组装纳米材料能够规避与细菌耐药性相关的机制,其作用靶点通常是在细菌不易引起耐药的...     

基于层层自组装的CuTsPc/DPDCH纳米管的制备

在阳极多孔氧化铝模板中利用层层自组装技术制备出了高度有序的聚电解质磺化酞菁铜(CuTsPc)/4,4′-联吡啶盐酸盐(DPDCH)纳米管, 并对其组装过程用UV-Vis, XRD和FT-IR进行了分析, 纳米管的微观形貌通过SEM和TEM进行表征. 结果表明, 第一层 CuTsPc和第二层DPDCH在AAO模板上的沉积平衡时间均约为60 min, 沉积过程主要有三个阶段: 模板孔外的吸附过程、孔内扩散控制的沉积过程和孔内表面沉积控制过程. CuTsPc主要以磺酸根吸附于AAO模板上. CuTsPc/DPDCH纳米管为非晶态体系. CuTsPc/DPDCH纳米管的外径和壁厚分别为200和20 nm, 外径受控于AAO模板的孔径, 壁厚与组装的层数有关, 利用此方法还可以制备其他带有相反电荷的有机小分子对纳米管或纳米线.     

Nanostructured Micelle Nanotubes Self-Assembled from Dinucleobase Monomers in Water

Despite the central importance of aqueous amphiphile assemblies in science and industry, the size and shape of these nano-objects is often difficult to control with accuracy owing to the non-directional nature of the hydrophobic interactions that sustain them. Here, using a bioinspired strategy that consists of programming an amphiphile with shielded directional Watson–Crick hydrogen-bonding functions, its self-assembly in water was guided toward a novel family of chiral micelle nanotubes with partially filled lipophilic pores of about 2 nm in diameter. Moreover, these tailored nanotubes are successfully demonstrated to extract and host molecules that are complementary in size and chemical affinity.     

Nanostructured Micelle Nanotubes Self‐Assembled from Dinucleobase Monomers in Water

Despite the central importance of aqueous amphiphile assemblies in science and industry, the size and shape of these nano‐objects is often difficult to control with accuracy owing to the non‐directional nature of the hydrophobic interactions that sustain them. Here, using a bioinspired strategy that consists of programming an amphiphile with shielded directional Watson–Crick hydrogen‐bonding functions, its self‐assembly in water was guided toward a novel family of chiral micelle nanotubes with partially filled lipophilic pores of about 2 nm in diameter. Moreover, these tailored nanotubes are successfully demonstrated to extract and host molecules that are complementary in size and chemical affinity.     

Short Self‐Assembling Peptides Are Able to Bind to Copper and Activate Oxygen

We have shown that de novo designed peptides self‐assemble in the presence of copper to create supramolecular assemblies capable of carrying out the oxidation of dimethoxyphenol in the presence of dioxygen. Formation of the supramolecular assembly, which is akin to a protein fold, is critical for productive catalysis since peptides possessing the same functional groups but lacking the ability to self‐assemble do not catalyze substrate oxidation. The ease with which we have discovered robust and productive oxygen activation catalysts suggests that these prion‐like assemblies might have served as intermediates in the evolution of enzymatic function and opens the path for the development of new catalyst nanomaterials.     

Spatially Controlled Supramolecular Polymerization of Peptide Nanotubes by Microfluidics

Despite the importance of spatially resolved self‐assembly for molecular machines, the spatial control of supramolecular polymerization with synthetic monomers had not been experimentally established. Now, a microfluidic‐regulated tandem process of supramolecular polymerization and droplet encapsulation is used to control the position of self‐assembled microfibrillar bundles of cyclic peptide nanotubes in water droplets. This method allows the precise preferential localization of fibers either at the interface or into the core of the droplets. UV absorbance, circular dichroism and fluorescence microscopy indicated that the microfluidic control of the stimuli (changes in pH or ionic strength) can be employed to adjust the packing degree and the spatial position of microfibrillar bundles of cyclic peptide nanotubes. Additionally, this spatially organized supramolecular polymerization of peptide nanotubes was applied in the assembly of highly ordered two‐dimensional droplet networks.     

Self-Assembly of a Pyridine-Based Amphiphile Complexed with Regioisomeric Dihydroxy Naphthalenes into Supramolecular Nanotubes with Different Inner Diameters

A pyridine-based amphiphile complexed with 1,5-, 1,6-, 2,6-, or 2,7-dihydroxy naphthalene self-assembled in water to form nanotubes with inner diameters of 46, 38, 24, 18, and 11 nm in which the naphthalene molecules formed J-type aggregates. In contrast, the amphiphile complexed with 1,2-, 1,3-, 1,4-, 1,7-, 1,8-, or 2,3-dihydroxy naphthalene formed nanofibers in which the naphthalene molecules formed H-type aggregates. The inner diameter of the nanotubes strongly depended on the regioisomeric dihydroxy naphthalene. UV–vis, fluorescence, infrared spectroscopy, X-ray diffraction analysis, and differential scanning calorimetry showed that nanotubes with smaller inner diameters had weaker intermolecular hydrogen bonds between the tilted amphiphiles complexed with the naphthalene molecules within the membrane walls and showed larger Stokes shifts in the excimer fluorescence of the naphthalene moiety. These findings should be useful not only for fine-tuning the inner diameters of supramolecular nanotubes but also for controlling the aggregation states of functional aromatic molecules to generate nanostructures with useful optical and electronic properties in water.     

Aldolase Cascade Facilitated by Self‐Assembled Nanotubes from Short Peptide Amphiphiles

Early evolution benefited from a complex network of reactions involving multiple C?C bond forming and breaking events that were critical for primitive metabolism. Nature gradually chose highly evolved and complex enzymes such as lyases to efficiently facilitate C?C bond formation and cleavage with remarkable substrate selectivity. Reported here is a lipidated short peptide which accesses a homogenous nanotubular morphology to efficiently catalyze C?C bond cleavage and formation. This system shows morphology‐dependent catalytic rates, suggesting the formation of a binding pocket and registered enhancements in the presence of the hydrogen‐bond donor tyrosine, which is exploited by extant aldolases. These assemblies showed excellent substrate selectivity and templated the formation of a specific adduct from a pool of possible adducts. The ability to catalyze metabolically relevant cascade transformations suggests the importance of such systems in early evolution.