Formation, stability, and mobility of one-dimensional lipid Bilayers on polysilicon nanowires
Formation, stability, and mobility of one-dimensional lipid Bilayers on polysilicon nanowires
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DOI：
10.1021/nl071641w
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发表时间：
2007-11-01
期刊：
影响因子：
10.8
通讯作者：
Noy, Aleksandr
中科院分区：
文献类型：
--
作者：
Huang, Shih-Chieh J.;Artyukhin, Alexander B.;Noy, Aleksandr
弯曲的脂膜在生命系统中普遍存在，并且在许多生物过程中发挥重要作用。为了了解曲率和脂质组成如何影响膜的形成和流动性，我们组装并研究了混合的1，2-二油酰基-sn-甘油-3-磷酸胆碱（DOPC）和1，2-二油酰基-sn-甘油-3-磷酸乙醇胺（DOPE）支持的脂质双层在碳纳米管芯周围生长的非晶硅纳米线上，控制线直径范围为20至200 nm。我们发现，脂质囊泡融合到纳米线基板上，并形成连续的双层所有DOPC-DOPE混合物测试（与DOPE含量高达30%）。我们的测量结果表明，双分子膜支持的移动的，表现出快速恢复后的光漂白，并有一个低浓度的缺陷。脂质扩散系数在这些高曲率的管状膜的值相媲美的平坦的支持双层，并略有增加，随着纳米线直径的减小。一个自由空间扩散模型充分描述了双层曲率的脂质流动性的纳米线基板的直径大于50 nm的效果，但显示出显着的偏差，从实验值较小直径的纳米线。
Curved lipid membranes are ubiquitous in living systems and play an important role in many biological processes. To understand how curvature and lipid composition affect membrane formation and fluidity, we have assembled and studied mixed 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) supported lipid bilayers on amorphous silicon nanowires grown around carbon nanotube cores with controlled wire diameters ranging from 20 to 200 nm. We found that lipid vesicles fused onto nanowire substrates and formed continuous bilayers for all DOPC-DOPE mixtures tested (with the DOPE content of up to 30%). Our measurements demonstrate that nanowire-supported bilayers are mobile, exhibit fast recovery after photobleaching, and have a low concentration of defects. Lipid diffusion coefficients in these high-curvature tubular membranes are comparable to the values reported for flat supported bilayers and increase slightly with decreasing nanowire diameter. A free space diffusion model adequately describes the effect of bilayer curvature on the lipid mobility for nanowire substrates with diameters greater than 50 nm, but shows significant deviations from the experimental values for smaller diameter nanowires.