Deamer

A. Watts, T. J. VanderNoot. The electrical double layer at hquid-hquid interfaces. In A. G. Volkov, D. W. Deamer, eds. Liquid-Liquid Interfaces. Theory and Methods. Boca Raton CRC Press, 1996, pp. 77-102. 

A method resulting in improved encapsulation of aqueous phase by MLV is the so-called dehydration-rehydration procedure (Kirby and Gregoriadis, 1984 Shew and Deamer, 1985). The lipid (usually preformed liposomes) is dried (by either lyophilization or evaporation) in the presence of the aqueous solute to be entrapped, thus forming a mixed film with solute trapped between layers. Subsequent gradual rehydration with a minimum of aqueous phase leads to the formation of MLV with a high entrapment of the aqueous solutes added. 

Apart from the passive encapsulation methods, different active entrapment techniques are described in the literature. Nichols and Deamer (1976) prepared liposomes with a pH gradient across the membrane (acidic interior with respect to the external buffer). These liposomes efficiently incorporated several catecholamines added to the external buffer. The same technique has been used to concentrate doxorubicin (DXR) in pH gradient liposomes (Mayer et al., 1986b). 

Deamer, D., and Bangham, A. D. (1976). Large volume liposomes by an ether vaporization method, Biochim. Biophys. Acta. 443, 629-634. 

Nichols, J. W., and Deamer, D. W. (1976). Cathecholamine uptake and concentration by liposomes maintaining pH gradients, Eio-chim. Biophys. Acta, 455, 269-271. 

Volkov, A. G., and D. W. Deamer, Eds., Liquid-Liquid Interfaces Theory and Methods, CRC Press, Boca Raton, EL, 1996. 

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