Dyanmics and Stability of Membrane Systems (REU Supplement)

本课题是一项相关的理论和实验工作， 细胞大小囊泡的粘附和融合动力学，基于 薄膜的物理化学和流体力学。 这项研究的重点 聚集和聚结动力学之间的相似性 胶体系统中气泡和液滴的特性以及粘附的动力学， 不稳定性和融合的膜系统，其中特定的 膜的机械和渗透性能被考虑到 帐户. 变形渗透体的相互接近速率 膜，相互作用的膜之间的膜的稳定性， 在粘附期间膜接触的膨胀速率，以及 膜融合后的形状松弛进行了理论评估。 根据这些结果，囊泡粘附和融合的总时间为 计算为膜张力的函数，膜 渗透性、膜间力和液膜粘度。 的 细胞大小的磷脂囊泡的粘附和融合时间， 作为囊泡膜的函数进行测量 张力和水溶液中离子的浓度， 放置囊泡。 理论计算的粘附时间 和聚变的实验测量值进行了比较， 磷脂酰胆碱和磷脂酰丝氨酸囊泡。

This project is an interrelated theoretical and experimental work on the kinetics of adhesion and fusion of cell-size vesicles, based on physical chemistry and hydrodynamics of thin films. The study focuses on the similarity between the kinetics of aggregation and coalescence of bubbles and drops in colloid systems and the kinetics of adhesion, instability, and fusion in membrane systems, where the specific mechanical and permeability properties of membranes are taken into account. The rate of mutual approach of deformable permeable membranes, the stability of films between interacting membranes, the rate of expansion of membrane contact during adhesion, and the rate of shape relaxation after membrane fusion are evaluated theoretically. From these results, the total times of vesicle adhesion and fusion are calculated as a function of the membrane tension, membrane permeability, intermembrane forces and liquid film viscosity. The times of adhesion and fusion of cell-size phospholipid vesicles, held by micropipettes, are measured as a function of the vesicle membrane tensions and the concentration of ions in the water solutions where the vesicles are placed. The theoretically calculated times of adhesion and fusion are compared with the experimentally measured values for phosphatidylcholine and phosphatidylserine vesicles.