Liposomes amphipathic lipids forming

Liposomes are stable microscopic vesicles formed by phospholipids and similar amphipathic lipids. Liposome properties vary substantially with lipid composition, size, surface charge, and the method of preparation. They are therefore divided into three classes based on their size and number of bilayers. 

Introduction - Liposomes are vesicles composed of one or more lipid bilayers completely surrounding an internal aqueous space. They are usually composed of phospholipids either in pure form or In combination with other amphipathic molecules such as sterols, long chain bases or acids, or membrane proteins. The structure of liposomes varies from large (0.5->5y) multllamellar vesicles to small ( 300 A) unilamellar vesicles.2,3 More recently, new methods have been reported describing the formation of unilamellar vesicles of intermediate size. >5.6 xhe general properties of liposomes and their interaction with various macromolecules have been described in several reviews. ... 

Woodle MC, Engbers CM, Zalipsky S. New amphipathic polymer-lipid conjugates forming long-circulating reticuloendothelial system-evading liposomes. Bioconjugate Chem 1994 5 493 96. 

Although a variety of amphipathic molecules can be used to form the bilayer, the major lipidic components of liposomes are usually phospholipids, amphiphilic moieties with a hydrophilic head group and two hydrophobic chains. The phospholipid molecules form a closed bilayer... 

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