Relation of Liposomes to Cell Membranes
The observation that phospholipid can form osmotically active vesicles was originally reported in 1965 by Bangham and co-workers. 1 (For reviews providing a historical context of this work, see References 2 and 3.) The first preparations were referred to as “swollen phospholipid” and “smectic mesophases”, and the term “liposome” was coined in 1968 by Sessa and Weissman. 4 The main thrust of the early work was to study permeability properties of pure lipid membranes and compare them with similar measurements in biological membrane systems. These results, together with those from planar lipid membranes, provide a foundation for our understanding of the barrier role of the lipid bilayer moiety in biological membranes.