Cationic liposomes can efficiently carry nucleic acids into mammalian cells. This property is
tightly connected with their ability to fuse with negatively charged natural membranes (ie the
plasma membrane and endosomal membrane). We used FRET to monitor and compare the
efficiency of lipid mixing of two liposomal preparations—one of short-chained diC14-amidine
and one of long-chained unsaturated DOTAP—with the plasma membrane of HeLa cells.
The diC14-amidine liposomes displayed a much higher susceptibility to lipid mixing with the …