共查询到20条相似文献,搜索用时 15 毫秒
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Romina Zappacosta Monica Semeraro Massimo Baroncini Serena Silvi Massimiliano Aschi Alberto Credi Antonella Fontana 《Small (Weinheim an der Bergstrasse, Germany)》2010,6(8):952-959
The effect of the luminescent heteroaromatic electron acceptor N,N′‐dimethyl‐2,7‐diazapyrenium dichloride (DM‐DAP2+) on the stability of 1‐palmitoyl‐2‐oleoylphosphatydilcholine (POPC) liposomes is determined on the basis of the rate of release of different fluorescent probes entrapped within the liposome. The experiments show that DM‐DAP2+ exerts a substantial destabilizing action on the liposomal bilayer, particularly at low concentrations. Molecular dynamics simulations suggest that the activity of DM‐DAP2+ is related to its tendency to surround itself with water molecules, conceivably favoring the formation of transient pores across the bilayer. 相似文献
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Fabio Lolicato Loic Joly Hector Martinez‐Seara Giovanna Fragneto Ernesto Scoppola Francesca Baldelli Bombelli Ilpo Vattulainen Jaakko Akola Marco Maccarini 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(23)
Understanding the molecular mechanisms governing nanoparticle–membrane interactions is of prime importance for drug delivery and biomedical applications. Neutron reflectometry (NR) experiments are combined with atomistic and coarse‐grained molecular dynamics (MD) simulations to study the interaction between cationic gold nanoparticles (AuNPs) and model lipid membranes composed of a mixture of zwitterionic di‐stearoyl‐phosphatidylcholine (DSPC) and anionic di‐stearoyl‐phosphatidylglycerol (DSPG). MD simulations show that the interaction between AuNPs and a pure DSPC lipid bilayer is modulated by a free energy barrier. This can be overcome by increasing temperature, which promotes an irreversible AuNP incorporation into the lipid bilayer. NR experiments confirm the encapsulation of the AuNPs within the lipid bilayer at temperatures around 55 °C. In contrast, the AuNP adsorption is weak and impaired by heating for a DSPC–DSPG (3:1) lipid bilayer. These results demonstrate that both the lipid charge and the temperature play pivotal roles in AuNP–membrane interactions. Furthermore, NR experiments indicate that the (negative) DSPG lipids are associated with lipid extraction upon AuNP adsorption, which is confirmed by coarse‐grained MD simulations as a lipid‐crawling effect driving further AuNP aggregation. Overall, the obtained detailed molecular view of the interaction mechanisms sheds light on AuNP incorporation and membrane destabilization. 相似文献
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Cholesterol-Containing Liposomes Decorated With Au Nanoparticles as Minimal Tunable Fusion Machinery
Ester Canepa Davide Bochicchio Giorgia Brosio Paulo Henrique Jacob Silva Francesco Stellacci Silvia Dante Giulia Rossi Annalisa Relini 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(23):2207125
Membrane fusion is essential for the basal functionality of eukaryotic cells. In physiological conditions, fusion events are regulated by a wide range of specialized proteins, operating with finely tuned local lipid composition and ionic environment. Fusogenic proteins, assisted by membrane cholesterol and calcium ions, provide the mechanical energy necessary to achieve vesicle fusion in neuromediator release. Similar cooperative effects must be explored when considering synthetic approaches for controlled membrane fusion. We show that liposomes decorated with amphiphilic Au nanoparticles (AuLips) can act as minimal tunable fusion machinery. AuLips fusion is triggered by divalent ions, while the number of fusion events dramatically changes with, and can be finely tuned by, the liposome cholesterol content. We combine quartz-crystal-microbalance with dissipation monitoring (QCM-D), fluorescence assays, and small-angle X-ray scattering (SAXS) with molecular dynamics (MD) at coarse-grained (CG) resolution, revealing new mechanistic details on the fusogenic activity of amphiphilic Au nanoparticles (AuNPs) and demonstrating the ability of these synthetic nanomaterials to induce fusion regardless of the divalent ion used (Ca2+ or Mg2+). The results provide a novel contribution to developing new artificial fusogenic agents for next-generation biomedical applications that require tight control of the rate of fusion events (e.g., targeted drug delivery). 相似文献
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Wenbin Wang Yin‐Bo Zhu Qunlei Wen Yutang Wang Jun Xia Caicai Li Ming‐Wei Chen Youwen Liu Huiqiao Li Heng‐An Wu Tianyou Zhai 《Advanced materials (Deerfield Beach, Fla.)》2019,31(28)
Integrating thermodynamically favorable ethanol reforming reactions with hybrid water electrolysis will allow room‐temperature production of high‐value organic products and decoupled hydrogen evolution. However, electrochemical reforming of ethanol has not received adequate attention due to its low catalytic efficiency and poor selectivity, which are caused by the multiple groups and chemical bonds of ethanol. In addition to the thermodynamic properties affected by the electronic structure of the catalyst, the dynamics of molecule/ion dynamics in electrolytes also play a significant role in the efficiency of a catalyst. The relatively large size and viscosity of the ethanol molecule necessitates large channels for molecule/ion transport through catalysts. Perforated CoNi hydroxide nanosheets are proposed as a model catalyst to synergistically regulate the dynamics of molecules and electronic structures. Molecular dynamics simulations directly reveal that these nanosheets can act as a “dam” to enrich ethanol molecules and facilitate permeation through the nanopores. Additionally, the charge transfer behavior of heteroatoms modifies the local charge density to promote molecular chemisorption. As expected, the perforated nanosheets exhibit a small potential (1.39 V) and high Faradaic efficiency for the conversion of ethanol into acetic acid. Moreover, the concept in this work provides new perspectives for exploring other molecular catalysts. 相似文献
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SMART Design of a Bulk‐Capped Supramolecular Segment for the Assembly into Organic Interdigital Lipid Bilayer‐Like (ILB) Nanosheets 下载免费PDF全文
Yin‐Xiang Li Sha‐Sha Wang Yang Yu He Zhang Wu‐You Wang Ru‐Qian Yang Ling‐Hai Xie Feng Liu Zong‐Qiong Lin Nai‐En Shi Li‐Tao Sun Wei Huang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(6)
Rational molecular design for the organic nanocrystal morphology still remains a challenge due to the structural diversity and complicated weak intermolecular interactions. In this work, a typical attractor–repulsor molecule N,N‐diphenyl‐4‐(9‐phenyl‐fluoren‐9‐yl) phenylamine (TPA‐PF) is designed to explore a general assembly strategy for 2D nanocrystals. Via an interdigital lipid bilayer‐like (ILB) molecular packing mode, large‐sized lamellar 2D nanosheets are obtained with a length:width:thickness ratio as ≈2500:1000:1. The d‐spacing of the largest (001) plane is 1.32 nm, which equals to the thickness of a single interdigital stacking layer. The synergetic effect of the attractive supramolecular segment (TPA) and the repulsive bulky group (PF) is supposed to be the critical factor for the ILB packing that leads to the 2D structures. The attractor–repulsor molecule design is expected to be an effective strategy for the growth of 2D nanocrystals based on small organic molecules. 相似文献
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Pedro Chamorro-Posada Pablo Martín-Ramos Francisco M. Sánchez-Arévalo 《Fullerenes, Nanotubes and Carbon Nanostructures》2018,26(3):137-144
A computational study of the properties of polymeric carbon nitride using molecular dynamics is presented. The analysis of ideal infinite-extent sheets permits to evaluate the effect of temperature on the network of hydrogen bonds responsible for the linkage of the material. The weakening of this binding mechanism at sufficiently high temperatures, together with the inter-layer interactions characteristic of this type of 2D materials, is shown to determine the conformation properties of polymeric carbon nitride at the nanoscale. The results obtained from the simulation of finite samples in the canonical ensemble at varying temperatures are consistent with those from the characterization of our experimentally synthesized samples. Hydrogen bonding between adjacent polymer ribbons leads this process and is the cause of the typical crumpled structure of this material. 相似文献
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Chia‐Wei Lee Ya‐Ling Chiang Ji‐Ting Liu Yi‐Xian Chen Chau‐Hwang Lee Yeng‐Long Chen Ing‐Shouh Hwang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(40)
Recent studies indicate that changing the physical properties of lipid bilayers may profoundly change the function of membrane proteins. Here, the effects of dissolved nitrogen and oxygen molecules on the mechanical properties and stability of lipid bilayers are investigated using differential confocal microscopy, atomic force microscopy, and molecular dynamics simulations. All experiments evidence the presence of dissolved air gas in lipid bilayers prepared without gas control. The lipid bilayers in degassed solutions are softer and less stable than those in ambient solutions. High concentrations of nitrogen increase the bending moduli and stability of the lipid bilayers and impede phase separation in ternary lipid bilayers. The effect of oxygen is less prominent. Molecular dynamics simulations indicate that higher nitrogen affinity accounts for increased rigidity. These findings have fundamental and wide implications for phenomena related to lipid bilayers and cell membranes, including the origin of life. 相似文献
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2D Nanocrystals: SMART Design of a Bulk‐Capped Supramolecular Segment for the Assembly into Organic Interdigital Lipid Bilayer‐Like (ILB) Nanosheets (Small 6/2018) 下载免费PDF全文
Yin‐Xiang Li Sha‐Sha Wang Yang Yu He Zhang Wu‐You Wang Ru‐Qian Yang Ling‐Hai Xie Feng Liu Zong‐Qiong Lin Nai‐En Shi Li‐Tao Sun Wei Huang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(6)
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Mai N. Vu Hannah G. Kelly Adam K. Wheatley Scott Peng Emily H. Pilkington Nicholas A. Veldhuis Thomas P. Davis Stephen J. Kent Nghia P. Truong 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(33)
A key concept in nanomedicine is encapsulating therapeutic or diagnostic agents inside nanoparticles to prolong blood circulation time and to enhance interactions with targeted cells. During circulation and depending on the selected application (e.g., cancer drug delivery or immune modulators), nanoparticles are required to possess low or high interactions with cells in human blood and blood vessels to minimize side effects or maximize delivery efficiency. However, analysis of cellular interactions in blood vessels is challenging and is not yet realized due to the diverse components of human blood and hemodynamic flow in blood vessels. Here, the first comprehensive method to analyze cellular interactions of both synthetic and commercially available nanoparticles under human blood flow conditions in a microvascular network is developed. Importantly, this method allows to unravel the complex interplay of size, charge, and type of nanoparticles on their cellular associations under the dynamic flow of human blood. This method offers a unique platform to study complex interactions of any type of nanoparticles in human blood flow conditions and serves as a useful guideline for the rational design of liposomes and polymer nanoparticles for diverse applications in nanomedicine. 相似文献
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Zheng Deng Ting Wan Danke Chen Wen Ying Yu‐Jia Zeng Youguo Yan Xinsheng Peng 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(34)
2D materials hold promising potential for novel gas separation. However, a lack of in‐plane pores and the randomly stacked interplane channels of these membranes still hinder their separation performance. In this work, ferrocene based‐MOFs (Zr‐Fc MOF) nanosheets, which contain abundant of in‐plane micropores, are synthesized as porous supports to fabricate Zr‐Fc MOF supported ionic liquid membrane (Zr‐Fc‐SILM) for highly efficient CO2 separation. The micropores of Zr‐Fc MOF nanosheets not only provide extra paths for CO2 transportation, and thus increase its permeance up to 145.15 GPU, but also endow the Zr‐Fc‐SILM with high selectivity (216.9) of CO2/N2 through the nanoconfinement effect, which is almost ten times higher than common porous polymer SILM. Furthermore, based on the photothermal‐responsive properties of Zr‐Fc MOF, the performance is further enhanced (35%) by light irradiation through a photothermal heating process. This provides a brand new way to design light facilitating gas separation membranes. 相似文献
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通过共溶剂法制备了由石墨(GN)和多壁碳纳米管(MWCNTs)掺杂的聚乳酸(PLA)纳米复合材料,借助扫描电镜等手段,研究了MWCNTs用量对复合材料微观结构、热稳定性、导热和导热性能及介电性能的影响。结果显示,MWC-NTs和GN在PLA基体中形成了稳定的导电和导热网络结构,从而导致复合材料具有较低的导电和导热逾渗阈值,其值约为MWCNTs/GN=0.5/1。MWCNTs和GN均匀分散和协同增强效应促使复合材料热稳定性、导热和导电性能明显提高。与纯PLA相比,填料在逾渗阈值附近的复合材料的初始分解温度提高了近16℃,导热系数提高了1倍,体积电阻降低了109数量级。 相似文献
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Nelson Monteiro Albino Martins Rui L. Reis Nuno M. Neves 《Journal of the Royal Society Interface》2014,11(101)
Liposomes are vesicular structures made of lipids that are formed in aqueous solutions. Structurally, they resemble the lipid membrane of living cells. Therefore, they have been widely investigated, since the 1960s, as models to study the cell membrane, and as carriers for protection and/or delivery of bioactive agents. They have been used in different areas of research including vaccines, imaging, applications in cosmetics and tissue engineering. Tissue engineering is defined as a strategy for promoting the regeneration of tissues for the human body. This strategy may involve the coordinated application of defined cell types with structured biomaterial scaffolds to produce living structures. To create a new tissue, based on this strategy, a controlled stimulation of cultured cells is needed, through a systematic combination of bioactive agents and mechanical signals. In this review, we highlight the potential role of liposomes as a platform for the sustained and local delivery of bioactive agents for tissue engineering and regenerative medicine approaches. 相似文献
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Simulation of a confined polymer in solution using the dissipative particle dynamics method 总被引:1,自引:0,他引:1
Y. Kong C. W. Manke W. G. Madden A. G. Schlijper 《International Journal of Thermophysics》1994,15(6):1093-1101
The dynamics of a bead-and-spring polymer chain suspended in a sea of solvent particles are examined by dissipative particle dynamics (DPD) simulations. The solvent is treated as a structured medium, comprised of particles subject to both solvent-solvent and solvent-polymer interactions and to stochastic Brownian forces. Thus hydrodynamic interactions among the beads of the polymer evolve naturally from the dynamics of the solvent particles. DPD simulations are about two orders of magnitude faster than comparable molecular dynamics simulations. Here we report the results of an investigation into the effects of confining the dissolved polymer chain between two closely spaced parallel walls. Confinement changes the polymer configuration statistics and produces markedly different relaxation times for chain motion parallel and perpendicular to the surface. This effect may be partly responsible for the gap width-dependent theological properties observed in nanoscale rheometry.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado, U.S.A. 相似文献
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以硫代氨基脲(CH5N3S)为还原剂, 通过还原氧化石墨(GO)制备了石墨烯纳米片(GNS)。利用XRD, FE-SEM, AFM和UV-Vis光谱对产物的结构和形貌进行分析, 并使用循环伏安和恒流充放电等测试手段来表征其超级电容性能。实验结果表明, 所制备的GNS具有良好的结晶状态, 并且在水溶液中具有良好的分散性。以GNS纳米片为电极材料, 在3 mol/L KOH电解质溶液中, 在500 mA/g电流密度测试条件下所得比电容量为75 F/g。而且GNS纳米片显示出了良好的电化学循环稳定性。 相似文献