INTERACTION OF SODIUM ALKYL SULFATES WITH EGG-YOLK LECITHIN VESICLES

The interaction of three anionic surfactants - sodium alkyl (decyl-, d odecyl-, tetradecyl-) sulphates - with unilamellar liposomes from egg yolk lecithin was studied fluorometrically by monitoring the leakage o f the marker 6-carboxyfluorescein. An increase in leakage rate was obs erved with increasing surfactant concentration; very small quantities of surfactant depending on its alkyl chain could disrupt the vesicles thus release the whole entrapped marker immediately after mixing with vesicles. Light scattering results suggest an increase in vesicle size followed by the formation of mixed micelles of surfactant and phospho lipid molecules. The presence of cholesterol in the vesicle decreased the leakage of the marker due to its rigidifying effect.