Intact vesicle adsorption and supported biomembrane formation from vesicles in solution:: Influence of surface chemistry, vesicle size, temperature, and osmotic pressure
Intact vesicle adsorption and supported biomembrane formation from vesicles in solution:: Influence of surface chemistry, vesicle size, temperature, and osmotic pressure
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DOI：
10.1021/la0263920
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发表时间：
2003-03-04
期刊：
影响因子：
3.9
通讯作者：
Kasemo, B
中科院分区：
文献类型：
--
作者：
Reimhult, E;Höök, F;Kasemo, B
采用石英晶体微平衡-耗散（QCM-D）技术研究了小单层蛋黄磷脂酰胆碱囊泡的吸附动力学，考察了表面化学（SiO2、Si 3 N4、Au、TiO 2和Pt）、温度（273-303 K）、囊泡尺寸（25-200 nm）和渗透压对吸附动力学的影响。在SiO2和Si 3 N4上，囊泡在低覆盖率下完整吸附，然后在临界覆盖率下转化为双层。在二氧化钛，氧化铂，氧化Au，囊泡吸附完整的所有覆盖率和所有研究的温度。囊泡大小的变化不会改变任何表面上的定性行为，但定量差异提供了有关表面诱导的囊泡变形的重要信息。在低覆盖率制度（囊泡吸附完整的所有表面上），变形是大得多的SiO2比在表面上的双层形成不发生。这归因于SiO2上较强的囊泡-表面相互作用。双分子层的形成是热激活的，表观活化能为63-78 kJ/mol。渗透压促进双层的形成，特别是当外部盐浓度高于内部时。取决于制备条件，不同量的未破裂囊泡被困在SiO2上的饱和双层中，但使用升高的温度和/或高渗透压，该分数可以有效地降低到检测水平以下。
The adsorption kinetics of small unilamellar egg-yolk phosphatidylcholine vesicles was investigated by the quartz crystal microbalance-dissipation (QCM-D) technique, as a function of surface chemistry (on SiO2, Si3N4, Au, TiO2, and Pt), temperature (273-303 K), vesicle size (25-200 nm), and osmotic pressure. On SiO2 and Si3N4, the vesicles adsorb intact at low coverage, followed by transformation to a bilayer at a critical coverage. On TiO2, oxidized Pt, and oxidized Au, the vesicles adsorb intact at all coverages and all studied temperatures. Variation of vesicle size does not change the qualitative behavior on any of the surfaces, but the quantitative differences provide important information about surface-induced vesicle deformation. In the low-coverage regime (where vesicles adsorb intact on all surfaces), the deformation is much larger on SiO2 than on the surfaces where bilayer formation does not occur. This is attributed to stronger vesicle-surface interaction on SiO2. The bilayer formation is thermally activated with an apparent activation energy of 63-78 kJ/mol. Osmotic pressure promotes bilayer formation, especially when the external salt concentration is higher than the internal one. Depending on preparation conditions, a varying amount of nonruptured vesicles are trapped in the saturated bilayer on SiO2, but the fraction can be efficiently reduced to below the detection level using elevated temperature and/or high osmotic stress.