Electrospun Nanofibers Modified with Phospholipid Moieties for Enzyme Immobilization

Summary: PANCMPCs containing phospholipid side moieties were electrospun into nanofibers with a mean diameter of 90 nm. Field emission SEM was used to characterize the morphologies of the nanofibers. These phospholipid‐modified nanofibers were explored as supports for enzyme immobilization due to the characteristics of excellent biocompatibility, high surface/volume ratio, and porosity, which were beneficial to the catalytic efficiency and activity of immobilized enzymes. Lipase from Candida rugosa was immobilized on these nanofibers by adsorption. Preliminary results indicated that the properties of the immobilized lipase on these phospholipid‐modified nanofibers were greatly promising.

Schematic representation of the structure and electrostatic properties of phospholipid‐modified nanofibers.     

Synthesis of Novel Biomimetic Zwitterionic Phosphorylcholine‐Bound Chitosan Derivative

Summary: Water‐soluble biomimetic chitosan derivative conjugating zwitterionic phosphorylcholine was efficiently prepared through Atherton‐Todd reaction under the mild conditions, and the possible formation mechanism of zwitterionic product was related to the nucleophilic attack of adjacent 3‐hydroxyl on the D ‐glucosamine residue to phosphorus with the help of base. UV absorption and melting behaviors of DNA/phosphorylcholine‐bound chitosan derivative showed that the phosphorylcholine‐bound chitosan derivative could be a new carrier for long‐circulating macromolecular drug delivery.

Structure of zwitterionic PC‐chitosan.     

Catalytic Activity of Copper(II) Enzyme-like Catalysts,Prepared by Molecular Imprinting Technique in Oxidation of Phenols

Summary: Molecularly imprinted polymer copper(II) catalysts were prepared by suspension polymerization of 4-vinylpyridine, trimethylolpropane trimethacrylate (series A) and additional monomer – acrylonitrile (series B) in the presence of Cu(II) ions and template: 4-metoxybenzyl alcohol; two samples were also prepared by surface molecular imprinting technique utilizing W/O emulsion. The catalytic activity was tested in model oxidation reactions of hydroquinone and 2,5-di-tert-butylhydroquinone using hydrogen peroxide. The imprinted catalysts were more effective in both reactions than non-imprinted but their activity strongly depended on Cu(II) loading. Surface imprinted samples showed the highest activity (L_H up to 100%).     

pH值对正十八烷微胶囊合成与性能的影响

pH值对正十八烷微胶囊合成与性能的影响;微胶囊;相变材料;正十八烷     

Preparation and Characterization of SiO2-coated 2,4-H exa diyn- 1,6-bis（ ethylurea ） Mic rocapsules

A novel kind of time-temperature indicator, SiO2-coated 2,4-hexadiyn-1,6-bis（ethylurea） microcapsules, has been fabricated by coating SiO2 on 2,4-hexadiyn-1,6-bis（ethylurea）. This kind of microcapsules is a model hydrophilic indicator, its stability is improved. And temperature-induced color change is irreversible even under varying irradiation. The influences of ammonia, tetraethyl orthosilicate（TEOS） and temperature on the product have been investigated. 2,4-Hexadiyn-1,6-bis（ethylurea） and the coated particles have been characterized by means of elemental analysis, mass spectrum, FTIR and Raman spectra and DSC, SEM, TEM and DLS analyses. The results indicate that 2,4-hexadiyn-1,6-bis（ethylurea）/SiO2 ratios, ammonia concentration and temperature could modulate the monodis- persity and size of the microcapsules. The experiments indicate that when the molar ratio of 2,4-hexadiyn- 1,6-bis（ethylurea）/SiO2/ammonia is 1：3：3.5 and temperature is 40℃ , the obtained microcapsules are well coated with the best monodispersity. Such sustained-release and hydrophilic microcapsules have very good prospects as a novel time-temoerature chromatic indicator.     

聚合物仿生润滑剂研究进展

生物体内界面之间表现出了极低的摩擦系数,生物大分子润滑剂在其中起到了重要的润滑作用.受此启发,仿生润滑剂的设计和相关润滑机理的研究引起了科研工作者的广泛关注.本文从结构仿生和功能仿生两个方面,综述了聚合物仿生润滑剂的研究进展,分类介绍了水溶性高分子、聚合物微凝胶、聚合物刷修饰复合微球作为仿生润滑液的设计思路、润滑机理及应用研究.     

生物矿化、仿生合成与形貌调控

介绍了生物矿化材料的种类、结构、特点、形貌调控原则以及基于微生物、蛋白质、多肽、氨基酸和核酸等晶体调节剂的生物矿化材料的合成,总结了近年来生物矿化和彷生合成领域的研究进展.     

纳米粒子微囊的界面自组装*

微囊是一类重要的功能性材料,在生物医药研究领域有重要用途。微囊的囊壁构建材料一般为脂质体和聚合物。以纳米粒子作为囊壁可将纳米粒子独特的物理化学性质整合到微囊中,使微囊具有机械强度高、渗透性可控、表面易于修饰和容易实现负载物的可控释放等特点,这种新型微囊在生物转运研究领域有潜在的应用前景。本文综述了以纳米粒子作为囊壁的微囊自组装研究进展,介绍了微囊自组装基本理论、囊壁的构建方法、微囊多分散性的改善方法,最后对纳米级微囊的自组装所面临的技术难点进行了讨论,并对纳米级微囊自组装的发展方向进行了展望。     

微胶囊填充型自修复聚合物及其复合材料

微胶囊填充型自修复聚合物及其复合材料是近年来高分子科学界的研究热点之一。本文介绍了含有微胶囊聚合物复合材料自修复的概念和机理,综述了近5年来针对不同基体材料的微胶囊自修复研究情况,包括环氧树脂、乙烯基酯树脂、纤维增强环氧树脂复合材料、弹性体以及聚甲基丙烯酸甲酯等基体材料。本文同时介绍了微胶囊的芯材和壁材、微胶囊的粒径、修复时间和压强等因素对复合材料自修复性能的影响,以及自修复效果的评价方法。最后对微胶囊填充型自修复聚合物及其复合材料的研究前景进行了展望。     

Illustrating the power of singlet oxygen chemistry in a synthetic context: biomimetic syntheses of litseaverticillols A-G, I and J and the structural reassignment of litseaverticillol E

Biomimetic syntheses of the litseaverticillols A-G, I and J are reported herein. The syntheses rely heavily on the application of two different modes of reaction for photochemically generated singlet oxygen, namely, the [4+2] cycloaddition of singlet oxygen (1O2) with furans and the ene reaction of 1O2 with double bonds. The highlight of these syntheses is a one-pot cascade sequence, involving five synthetic operations initiated by a [4+2] reaction, to form the fully functionalised litseaverticillol core. A series of regioselective ene reactions are then used to appositely functionalise the side chains. The synthesis of litseaverticillol E (both its originally proposed and its actual structures) allows a structural reassignment of this natural product.