Coagulation Behavior of Egg PC Vesicles with Different Particle Sizes

Abstract

The importance of the interaction between amphoteric phospholipid bilayer membranes has been pointed out by many authors to understand the membrane stability against coagulation and membrane fusion.^1–3 Long-range interaction force, felt during the initial mutual approach of two membranes, is relatively well understood theoretically and experimentally. However, short-range forces occurring near contact between membranes have not realized fully, which come from specific nature of chemical groups. It has been realized that the membrane made of hygroscopic phospholipid experiences a strong repulsive force at close contact. The force is called 1“hydration force1” or 1“steric force1”, which originates from the work of removing water molecules from the membrane surface or is caused by the local thermal motion of the membrane.⁴ Below 2–3 nm separation, the hydration force dominates over Van der Waals attractive force and poses a significant energetic barrier to membrane contact. As the result, colloid particles consisted of those phospholipid membranes can be stably dispersed in electrolyte solution.