KINETICS OF LIPOSOME VOLUME AND PERMEABILITY CHANGES DURING THE LIPID PHASE-TRANSITIONS

In order to describe the changes in spherical liposome sizes in the region of the lipid phase transition from the liquid crystalline to the gel state, a kinetic model has been developed. Relations were found between the membrane tension and the water flow through the membrane and between its permeability and the phase state of the lipid. The equations derived are solved by a numerical technique for dipalmitoylphosphatidylcholine and dimyristoylphosphatidylcholine liposomes at an arbitrary cooling rate. The results obtained allow us to connect the membrane tension-induced shift of the thermodynamic phase equilibrium and the other model parameters with the evolution of liposome size, which can be observed experimentally. The biological relevance of the model is discussed. © 1990.