Gruhn Thomas, Franke Thomas, Dimova Rumiana, Lipowsky Reinhard
Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany.
Langmuir. 2007 May 8;23(10):5423-9. doi: 10.1021/la063123r. Epub 2007 Apr 10.
Adhering vesicles with osmotically stabilized volume are studied with Monte Carlo simulations and optical microscopy. The simulations are used to determine the dependence of the adhesion area on the vesicle volume, the surface area, the bending rigidity, the adhesion energy per membrane area, and the adhesion potential range. The simulation results lead to a simple functional expression that is supplemented by a correction term for gravity effects. The obtained equation provides a new tool to analyze optical microscopy data and, thus, to measure the adhesion energy per area by analyzing the geometry of the adhering vesicle. The method can be applied in the weak and ultra-weak adhesion regime, where the adhesion energy per area is below 10(-6) J/m(2). By comparing the shapes of adhering vesicles with different reduced volumes, the bending rigidity can be estimated as well. The new approach is applied to experimental data for lipid vesicles on (i) an untreated and (ii) a monolayer-coated glass surface, providing ultra-weak and weak adhesion strength, respectively.
通过蒙特卡罗模拟和光学显微镜研究了具有渗透稳定体积的附着囊泡。模拟用于确定附着面积对囊泡体积、表面积、弯曲刚度、每膜面积的粘附能以及粘附势范围的依赖性。模拟结果得出一个简单的函数表达式，并辅以重力效应的校正项。所得方程为分析光学显微镜数据提供了一种新工具，从而通过分析附着囊泡的几何形状来测量每面积的粘附能。该方法可应用于每面积粘附能低于10^(-6) J/m²的弱粘附和超弱粘附状态。通过比较不同约化体积的附着囊泡的形状，也可以估计弯曲刚度。将这种新方法应用于脂质囊泡在（i）未处理的和（ii）单层涂层玻璃表面上的实验数据，分别提供了超弱和弱粘附强度。
