Dyanmics and Stability of Membrane Systems (REU Supplement)

膜系统的动力学和稳定性（REU 补充）

• 批准号: 8413990
• 负责人: Rakesh Jain
• 金额: $ 19.4万
• 依托单位: Carnegie-Mellon University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-01-15 至 1988-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8413990&HistoricalAwards=false
• 关键词: Dyanmics; Stability; Membrane; Systems; REU

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.

本课题是基于薄膜的物理化学和流体动力学，对细胞大小的囊泡的粘附和融合动力学进行相关的理论和实验研究。该研究的重点是胶体系统中气泡和液滴的聚集和聚并动力学与膜系统中粘附、不稳定和融合动力学之间的相似性，其中考虑了膜的特定力学和渗透性。从理论上对可变形渗透膜的相互接近速率、相互作用膜间膜的稳定性、粘附过程中膜接触的膨胀速率以及膜融合后的形状松弛速率进行了评价。根据这些结果，计算了囊泡粘附和融合的总次数，并将其作为膜张力、膜渗透性、膜间力和液膜粘度的函数。细胞大小的磷脂囊泡的黏附和融合时间，由微移液管保持，作为囊泡膜张力和囊泡所在水溶液中离子浓度的函数进行测量。将理论计算的磷脂酰胆碱和磷脂酰丝氨酸囊泡的粘附和融合次数与实验测量值进行了比较。