Small unilamellar phospholipid vesicles and the theories of membrane formation

Abstract

Small unilamellar phospholipid vesicles (SUVs) are widely used as a model system in which to study the molecular interactions which occur in biological membranes. Israelachvili et al. and Mitchell and Ninham argue that provided the phospholipid concentration is sufficiently low, lipid aggregates will spontaneously form into SUVs which represent the equilibrium state of the lipid in water. Helfrich, Fromherz and Lasic adopt an alternative model and picture the phospholipid vesicle as a distortion of a planar membrane which requires energy for its formation and is inherently unstable. In the present work we examine these two approaches and their consequences in explaining the physical properti..