Edelfosine (1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine) is an anti-tumour cell
ether lipid with surface-active properties. Pure
edelfosine can be dispersed in aqueous media in the form of
micelles. One important, negative side effect of
edelfosine is that it is highly haemolytic. In this paper, we show that
edelfosine can be co-dispersed in water with certain
lipids (particularly
cholesterol,
campesterol or
beta-sitosterol) so that it gives rise to
liposomes. Surface pressure measurements demonstrate that
edelfosine is slowly released from these
liposomes. In liposomal form,
edelfosine remains apoptogenic for a variety of
leukemia cell lines, while its haemolytic effect is abolished. The phenomenon is explained on the basis of the complementarity of the molecular geometries of
sterols and
edelfosine.