6

I. Introduction ................................................................ 300 II. Kinetics of Transport in and Between Aqueous

Vesicles ........................................................................ 306 A. Lateral and Transversal Diffusion..................... 306

1. Flip-Flop ......................................................... 306 2. Lateral Diffusion ........................................... 309

B. Transport of Lipids and Other Molecules Between Vesicles (Exchange).............................. 311

C. Transport across Lipid Vesicle Bilayers ............ 315 III. Kinetic Studies of Vesicle-to-Micelle and

Micelle-to-Vesicle Transformations ........................... 320 IV. Fatty-Acid and Mixed Phospholipid/Fatty Acid

Vesicle Systems .......................................................... 332 V. Dynamic Changes Associated with Vesicle Phase

Transitions.................................................................. 334 VI. Effect of Applied Electric Fields on the

Properties of Vesicle Bilayers .................................... 336 VII. Conclusions ................................................................. 337 References ........................................................................... 338

I. INTRODUCTION

Vesicles are, in the simplest case, micron-sized spherical structures containing an inner aqueous compartment separated from the external water phase by a lipid or surfactant bilayer. A representative structure, which gives an idealized vesicle structure and some closely related surfactant configurations, is shown in Figure 6.1 (see also Chapter 1, Section V).