Estimation of liposome integrity by 1H-NMR spectroscopy

A fast and simple method of 1H-NMR spectroscopic control of liposome membrane integrity is suggested. The method is based on the redistribution of intensities between two singlet 1H-NMR signals--from intraliposomal marker compound (nitrilotriacetic acid sodium salt, 1H-NMR signal at 4 p.p.m.) and from its complex with Eu3+ added to the external medium (NMR signal of the complex at - 1 p.p.m.). The method permits registration of the kinetics of liposome destruction under the action of detergent or serum. It is shown that the presence of cholesterol in the membrane makes it more stable.