KINETICS OF LIPOSOME DISINTEGRATION FROM FOAM FILM STUDIES - EFFECT OF THE LIPID BILAYER PHASE STATE

The kinetics of interfacial liposome breakdown is investigated in the thin liquid film microinterferometric set up of Scheludko et al. Suspe nsions of small unilamellar vesicles of dimyristoylphosphatidylcholine are studied at temperatures above and below the temperature of the ma in gel-liquid crystal first order phase transition. The experimentally established time traces of the velocity of thinning of foam films are used to estimate the kinetic (rate) constants of interfacial liposome disintegration. New and previously established data for other lipids are summarized and compared with results from kinetic measurements of lipid monolayer formation. The thin film experiments confirm the exist ence of interfacial liposomal aggregates. A change in the kinetic beha viour is observed, due to the 'melting' of the hydrophobic tails in th e lipid aggregates. This may have various consequences of biological a nd pharmacological importance.