背景:巨大的单层囊泡(GUV),类似细胞的合成微米尺寸结构,组装时,薄脂质膜在水溶液中水合。最近报道了从薄膜水合方法获得的GUV的静态产率和尺寸分布的定量测量。动态数据,如产量的时间演变和规模分布,然而,不知道。动态数据可以提供对GUV组装途径的洞察和选择条件以获得具有所需大小分布的群体的指南。
方法:我们开发了\'停止时间\'技术,以表征自由浮动GUV种群的大小和摩尔产量分布的时间演变。我们还捕获了脂质膜上表面附着的GUV芽的高分辨率延时图像。我们从三种广泛使用的薄膜水化方法出发,系统地研究了GUV的组装动力学,PAPYRUS(一种解决方案中的纸对amphiphilehYdRation),温和的水合作用,和电铸。
结果:我们发现GUV的摩尔产率随时间变化的曲线表现出特征性的S形形状,具有初始产量,一个短暂的,然后是所有三种方法的稳态平台。GUV的种群显示出直径的右偏分布。分布的方差随时间增加。系统在120分钟内达到稳态。我们使用热力学动机的萌芽和合并(BNM)模型来合理化动力学。这些结果进一步了解了脂质动力学,并提供了首次实用参数来定制特定尺寸的GUV的生产以供应用。
BACKGROUND: Giant unilamellar vesicles (GUVs), cell-like synthetic micrometer size structures, assemble when thin lipid films are hydrated in aqueous solutions. Quantitative measurements of static yields and distribution of sizes of GUVs obtained from thin film hydration methods were recently reported. Dynamic data such as the time evolution of yields and distribution of sizes, however, is not known. Dynamic data can provide insights into the assembly pathway of GUVs and guidelines for choosing conditions to obtain populations with desired size distributions.
METHODS: We develop the \'stopped-time\' technique to characterize the time evolution of the distribution of sizes and molar yields of populations of free-floating GUVs. We additionally capture high resolution time-lapse images of surface-attached GUV buds on the lipid films. We systematically study the dynamics of assembly of GUVs from three widely used thin film hydration methods, PAPYRUS (Paper-Abetted amPhiphile hYdRation in aqUeous Solutions), gentle hydration, and electroformation.
RESULTS: We find that the molar yield versus time curves of GUVs demonstrate a characteristic sigmoidal shape, with an initial yield, a transient, and then a steady state plateau for all three methods. The population of GUVs showed a right-skewed distribution of diameters. The variance of the distributions increased with time. The systems reached steady state within 120 min. We rationalize the dynamics using the thermodynamically motivated budding and merging (BNM) model. These results further the understanding of lipid dynamics and provide for the first-time practical parameters to tailor the production of GUVs of specific sizes for applications.