Liposomes of controllable size in the range of 40 to 180 nm by defined dialysis of lipid/detergent mixed micelles.

Liposomes, in the size range of 40--180 nm, are formed when lipid and additives are solubilized with detergent, yielding defined mixed micelles, and the detergent is subsequently removed by controlled dialysis. Their most important properties are that they are indeed unilamellar with usefully large encapsulated volumes and are homogeneous in size. Liposomes have been formed from both natural and synthetic phospholipids with cholesterol and charged molecules added. This relatively simple technique may be particularly useful for encapsulating drugs, enzymes and other macromolecules and in studies of reconstitution of membrane proteins.