共查询到20条相似文献,搜索用时 15 毫秒
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Summary: A novel comb‐like poly(ethylene glycol) (CPEG), with dominant water‐soluble PEG, is found to spontaneously aggregate into vesicles above a certain concentration in water. The hollow, three‐dimensional structure of the vesicles is proven by TEM, SEM, and AFM. The diameters of the vesicles are from 200 to 500 nm with 50 nm walls. The spontaneously formed vesicles can be further cross‐linked by the reaction between divinyl sulfone (DVS) and the hydroxy groups in the side chains of the CPEG. The spontaneously formed vesicles with dense reactive hydroxy groups will have great potential in both applications and research.
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Xiaolin Li Jian Ji Xiaoli Wang Youxiang Wang Jiacong Shen 《Macromolecular rapid communications》2007,28(5):660-665
A novel comb‐like derivative CPEG‐g‐cholesterol was prepared by the reaction of cholesteryl chloroformate with hydroxyl groups of CPEG. The TEM and SEM results showed that CPEG‐cholesterol spontaneously aggregated vesicles with the membrane thickness of 4.27 ± 0.48 nm. Compared with the vesicles formed by comb‐like PEG (CPEG), the derivation of cholesteryl chloroformate increased the thickness of vesicle membrane and developed corrugations. The hydrophobic doxorubicin (Dox) was added into the solution of CPEG and CPEG‐g‐cholesterol to test their vesicle stability. The drug‐loaded vesicles of CPEG‐g‐cholesterol still existed but those of CPEG disappeared, which indicated that stability of vesicles was enhanced by the derived cholesteryl chloroformate. The vesicles were further cross‐linked by the reaction between divinyl sulfone (DVS) and the hydroxy groups in the side chains of the CPEG and CPEG‐g‐cholesterol. Both cross‐linked vesicles of CPEG and CPEG‐g‐cholesterol entrapped considerable hydrophobic Dox in the vesicles membrane. The spontaneous vesicles of CPEG‐g‐cholesterol and the crosslinked vesicles of CPEG and CPEG‐g‐cholesterol might have great potential as a cargo of the hydrophobic drug.
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Luigi Carbone Dr. Liberato Manna Dr. Carsten Sönnichsen Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(24):4282-4283
Amphiphilic hybrid materials are formed from polymer‐coated semiconductor nanoparticles that simulate a surfactant‐like response (see picture). The strength and density of the surface coating are the key assembling forces driving a transition from single particles to cylindrical or vesicular superstructures.
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Marija S. Nikolic Dr. Charlotta Olsson Andrea Salcher Andreas Kornowski Anja Rank Dr. Rolf Schubert Prof. Dr. Andreas Frömsdorf Dr. Horst Weller Prof. Dr. Stephan Förster Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(15):2752-2754
Nanoparticle brushes : Complex nanostructures can be formed by self assembly of amphiphilic CdSe/CdS core–shell nanoparticles that bear a brushlike layer of poly(ethylene oxide) chains. This route is based on controlling the volume fractions of hydrophilic and hydrophobic moieties within the particles and allows the formation of micellar, cylindrical, or vesicular nanoobjects (see picture).
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Yongbing Song Run Jiang Zheng Wang Lang Wang Yuhua Yin Baohui Li An‐Chang Shi 《Macromolecular theory and simulations》2016,25(6):559-570
The self‐assembled morphologies of cyclic amphiphiles, which are composed of a long hydrophobic block and a short hydrophilic block, in selective solutions are studied by using a simulated annealing method. The morphological dependence of the aggregates on solvent quality is investigated. The topology effects are studied by comparing results from linear counterparts of the amphiphiles. It is observed that, in addition to spherical micelles, cylindrical micelles, disklike micelles, vesicles, and large compound micelles, muticompartment vesicles with several fluidic cores can be formed by the cyclic systems. The morphologies are regulated by the interaction parameter εAS between the hydrophobic block and solvents. Furthermore, it is revealed that the differences of characteristics of the self‐assembled aggregates originate from the difference in architectural constraint. The wide region of forming multicompartment vesicles suggests that cyclic amphiphilic macromolecules could be a suitable candidate for applications to deliver multiple functional components by compartmentalizing different components in different confined space of vesicles. 相似文献
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Xiaoqiang Xue Fang Li Wenyan Huang Hongjun Yang Bibiao Jiang Yiliang Zheng Dongliang Zhang Jianbo Fang Lizhi Kong Guangqun Zhai Jianhai Chen 《Macromolecular rapid communications》2014,35(3):330-336
The novel hyperbranched poly(methyl acrylate)‐block‐poly(acrylic acid)s (HBPMA‐b‐PAAs) are successfully synthesized via single‐electron transfer‐living radical polymerization (SET‐LRP), followed with hydrolysis reaction. The copolymer solution could spontaneously form unimolecular micelles composed of the hydrophobic core (PMA) and the hydrophilic shell (PAA) in water. Results show that the size of spherical particles increases from 8.18 to 19.18 nm with increased pH from 3.0 to 12.0. Most interestingly, the unique regular quadrangular prisms with the large microstructure (5.70 μm in length, and 0.47 μm in width) are observed by the self‐assembly of unimolecular micelles when pH value is below 2. Such self‐assembly behavior of HBPMA‐b‐PAA in solution is significantly influenced by the pH cycle times and concentration, which show that increased polymer concentration favors aggregate growth.
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Getting the sizes sorted out : In recent years, there have been increasing numbers of reports about self‐assembled nano‐ or microtubular structures because of their potential uses in a variety of technical applications, which are largely determined by the tube sizes. This Focus Review highlights microsized self‐assembled organic tubular structures formed in aqueous solutions and organic solvents.
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Dr. Benjamin Gruber Prof. Dr. Burkhard König 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(2):438-448
Biological membranes play a key role for the function of living organisms. Thus, many artificial systems have been designed to mimic natural cell membranes and their functions. A useful concept for the preparation of functional membranes is the embedding of synthetic amphiphiles into vesicular bilayers. The dynamic nature of such noncovalent assemblies allows the rapid and simple development of bio‐inspired responsive nanomaterials, which find applications in molecular recognition, sensing or catalysis. However, the complexity that can be achieved in artificial functionalized membranes is still rather limited and the control of their dynamic properties and the analysis of membrane structures down to the molecular level remain challenging. 相似文献
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Crown‐Shaped Tungstogermanates as Solvent‐Controlled Dual Systems in the Formation of Vesicle‐Like Assemblies 下载免费PDF全文
Dr. Beñat Artetxe Dr. Santiago Reinoso Dr. Leire San Felices Prof. Juan M. Gutiérrez‐Zorrilla Prof. José A. García Fadi Haso Prof. Tianbo Liu Dr. Cristian Vicent 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(21):7736-7745
Reaction of early lanthanides, GeO2, and Na2WO4 in a NaOAc buffer results in large crown‐shaped polyoxometalates based on [Ln2GeW10O38]6? subunits. By using Ni2+ as a crystallizing agent, [Na?Ln12Ge6W60O228(H2O)24]35? ( Na?Ln12 ) hexamers formed by alternating β(1,5)/β(1,8) subunits were obtained for Ln=Pr, Nd. The addition of K+ led to a similar anion for Ln=Sm, namely, [K?Sm12Ge6W60O228(H2O)22]35? ( K?Sm12 ) and [K?K7Ln24Ge12W120O444(OH)12(H2O)64]52? ( K?Ln24 ) dodecamers that consist of a central core identical to K?Sm12 decorated with six external γ(3,4) subunits for Ln=Pr, Nd. These anions dissociate in water into hexameric cores and monomeric entities, as shown by ESI mass spectrometry. The former self‐assemble into spherical, hollow, and single‐layered blackberry‐type structures with radii of approximately 75 nm, as monitored by laser light scattering (LLS) and TEM techniques. Analogous studies performed for K?Nd24 in water/acetone mixtures show that the dodecamers remain stable and form in turn their own type of blackberries with sizes that increase from approximately 20 to 50 nm with increasing acetone content. This control over both the composition and size of the vesicle‐like assemblies is achieved for the first time by modifying the architecture of the species that undergoes supramolecular association through the solvent polarity. 相似文献
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Summary: Amphiphilic hyperbranched polyester (H20‐AM) with methacrylate end groups was synthesized based on hyperbranched aliphatic polyester (Boltorn™ H20). Narrow‐dispersed crosslinkable vesicles were obtained by dissolving H20‐AM in water, and characterized by laser light scattering and TEM. The hollow structural vesicle is composed of around 350 H20‐AM molecules, having a radius of around 40 nm and of 1.9 × 106 g · mL−1. The vesicles were fixed by crosslinking of methacrylate groups to form shape‐persistent structures.
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Xiao‐Li Sun Shuai Pei Jun‐Feng Wang Pan Wang Zhi‐Bin Liu Jun Zhang 《Journal of Polymer Science.Polymer Physics》2017,55(16):1220-1226
Molecular‐level understanding of the vesicular structure and formation process is beneficial for potential vesicle applications, especially in drug delivery. In this article, coarse‐grained molecular dynamics simulation was used to study the self‐assembly behavior of amphiphilic poly(acrylic acid)‐b‐polystyrene copolymers in water at different concentrations and PS/PAA block ratios. It was found that various spherical and tube‐like vesicles formed at PS/PAA 3:3 and 4:2. For spherical vesicles, analysis of vesicular structure indicated that the cavity size was influenced by copolymer concentration and wall thickness by the block ratio. Tube‐like vesicle was formed via the fusion of two spherical vesicles, and a key factor for this morphology is polymer movements between inner and outer layer. This simulation study identifies the key factors governing vesicle formation and structure, and provides a guidance to design and prepare various vesicles for wide applications in drug delivery. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1220–1226 相似文献
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Frontispiece: Crown‐Shaped Tungstogermanates as Solvent‐Controlled Dual Systems in the Formation of Vesicle‐Like Assemblies 下载免费PDF全文
Dr. Beñat Artetxe Dr. Santiago Reinoso Dr. Leire San Felices Prof. Juan M. Gutiérrez‐Zorrilla Prof. José A. García Fadi Haso Prof. Tianbo Liu Dr. Cristian Vicent 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(21)
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Dr. Zhigang Zhang Prof. Dr. Chuanlang Zhan Xin Zhang Shanlin Zhang Jianhua Huang Prof. Dr. Alexander D. Q. Li Prof. Dr. Jiannian Yao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(39):12305-12313
Supramolecular forces govern self‐assembly and further determine the final morphologies of self‐assemblies. However, how they control the morphology remains hitherto largely unknown. In this paper, we have discovered that the self‐assembled nanostructures of rigid organic semiconductor chromophores can be finely controlled by the secondary forces by fine‐tuning the surrounding environments. In particular, we used water/methanol/hydrochloric acid to tune the environment and observed five different phases that resulted from versatile molecular self‐assemblies. The representative self‐assembled nanostructures were nanotapes, nanoparticles and their 1D assemblies, rigid microplates, soft nanoplates, and hollow nanospheres and their 1D assemblies, respectively. The specific nanostructure formation is governed by the water fraction, Rw, and the concentration of hydrochloric acid, [HCl]. For instance, nanotapes formed at low [HCl] and Rw values, whereas hollow nanospheres formed when either the HCl concentration is high, or the water fraction is low, or both. The significance of this paper is that it provides a useful phase diagram by using Rw and [HCl] as two variables. Such a self‐assembly phase diagram maps out the fine control that the secondary forces have on the self‐assembled morphology, and thus allows one to guide the formation toward a desired nanostructure self‐assembled from rigid organic semiconductor chromophores by simply adjusting the two key parameters of Rw and [HCl]. 相似文献
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Colloidal molecules constructed from polymers and nanoparticles (NPs) have recently emerged as a novel class of building blocks for assembling functional hybrid materials. Particularly, self‐assembly of amphiphilic block copolymer (BCP)‐tethered NPs (BNPs) has shown great promise in the nanoscale design of functional hybrid materials. On the one hand, structurally the BNPs can be considered as molecular equivalents that are capable of self‐assembly at multiple hierarchical levels. On the other hand, the assembly of BNPs shows significant differences from molecular assembly due to their large dimension, complex geometry, and multi‐scale interactions involved in the assembly process. The manipulation of BCPs localized near the surface of the NPs offers an effective tool for engineering the interactions between NPs and hence the complexity of NP assembly. In this Feature Article, recent progresses on the self‐assembly of BNPs into functional materials are summarized. First, major strategies for assembling amphiphilic BNPs are highlighted. Secondly, the application of hybrid nanostructures (e.g., vesicles) assembled from BNPs in the field of biomedical imaging and delivery is discussed. Finally, current challenges and perspectives at this frontier are outlined.