Vesicle and bilayer formation of diphytanoylphosphatidylcholine (DPhPC) and diphytanoylphosphatidylethanolamine (DPhPE) mixtures and their bilayers' electrical stability
Vesicle and bilayer formation of diphytanoylphosphatidylcholine (DPhPC) and diphytanoylphosphatidylethanolamine (DPhPE) mixtures and their bilayers' electrical stability
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DOI：
10.1016/j.colsurfb.2010.10.017
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发表时间：
2011-02-01
影响因子：
5.8
通讯作者：
Duran, Randolph
中科院分区：
文献类型：
--
作者：
Andersson, Martin;Jackman, Joshua;Duran, Randolph
脂质双层在需要细胞膜模拟环境的应用中是令人感兴趣的。脂质双层的性能在很大程度上取决于组分脂质的物理和化学性质。由植烷酰脂质组成的脂质双层已被证明是合适的选择，因为它们表现出高的机械和化学稳定性。此外，这种双层具有高电阻。两种不同的植烷酰基脂质，1，2-二植烷酰基-sn-甘油-3-磷酸胆碱（DPhPC）和1，2-二植烷酰基-sn-甘油-3-磷酸乙醇胺（DPhPE），以及两者的各种组合已被研究了它们在水溶液中的行为，它们与固体表面的相互作用，以及它们的电稳定性。动态光散射，核磁共振扩散，和低温透射电子显微镜测量表明，纯DPhPC以及DPhPC和DPhPE的混合物组成的大于50%（摩尔%）DPhPC形成单层囊泡。如果总脂质浓度大于0.15 g/l，那么囊泡通过自发囊泡吸附和破裂的过程在等离子体处理的金和二氧化硅表面上形成固体支撑的双层，如通过石英晶体微天平与耗散监测和原子力显微镜所确定的。的固体支撑的双层表现出高度的粘弹性，可能是一个相对较高的量的吸水或不完全囊泡融合的效果。由大于50%DPhPE组成的脂质组合物形成小的花状囊泡结构，沿着具有离散的液晶结构，如通过低温透射电子显微镜所证明的。此外，使用尖端-浸渍方法对双层进行电生理学测量，并将双层保持其对跨双层施加的电势的电阻的能力作为脂质组成的函数进行评价。结果表明，脂质比例显着影响双层的电稳定性，与纯DPhPE具有最高的稳定性，其次是3DPhPC：7 DPhPE和7 DPhPC：3DPhPE以降序排列。由5DPhPC：5DPhPE组成的双层对所施加的电势具有最低的稳定性。(C)2010 Elsevier B. V.保留所有权利。
Lipid bilayers are of interest in applications where a cell membrane mimicking environment is desired. The performance of the lipid bilayer is largely dependent on the physical and chemical properties of the component lipids. Lipid bilayers consisting of phytanoyl lipids have proven to be appropriate choices since they exhibit high mechanical and chemical stability. In addition, such bilayers have high electrical resistances. Two different phytanoyl lipids, 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) and 1,2-diphytanoyl-sn-glycero-3-phosphoethanolamine(DPhPE), and various combinations of the two have been investigated with respect to their behavior in aqueous solutions, their interactions with solid surfaces, and their electrical stability. Dynamic light scattering, nuclear magnetic resonance diffusion, and cryogenic transmission electron microscopy measurements showed that pure DPhPC as well as mixtures of DPhPC and DPhPE consisting of greater than 50% (mol%) DPhPC formed unilamellar vesicles. If the total lipid concentration was greater than 0.15 g/l, then the vesicles formed solid-supported bilayers on plasma-treated gold and silica surfaces by the process of spontaneous vesicle adsorption and rupture, as determined by quartz crystal microbalance with dissipation monitoring and atomic force microscopy. The solid-supported bilayers exhibited a high degree of viscoelasticity, probably an effect of relatively high amounts of imbibed water or incomplete vesicle fusion. Lipid compositions consisting of greater than 50% DPhPE formed small flower-like vesicular structures along with discrete liquid crystalline structures, as evidenced by cryogenic transmission electron microscopy. Furthermore, electrophysiology measurements were performed on bilayers using the tip-dip methodology and the bilayers' capacity to retain its electrical resistance towards an applied potential across the bilayer was evaluated as a function of lipid composition. It was shown that the lipid ratio significantly affected the bilayer's electrical stability, with pure DPhPE having the highest stability followed by 3DPhPC:7DPhPE and 7DPhPC:3DPhPE in decreasing order. The bilayer consisting of 5DPhPC:5DPhPE had the lowest stability towards the applied electrical potential. (C) 2010 Elsevier B.V. All rights reserved.