a simple , rapid method for creating a lipidic vector for delivery of a therapeutic molecule entails bringing the molecule into contact with a polycation , thereby forming a complex , and then mixing the complex with an anionic lipidic preparation . tissue - specific targeting peptides , fusogenic peptides and nucleus - targeting peptides also can be added to the lipid preparation . the result is a stable lipidic vector of reduced immunogenicity and cytotoxicity . the vector also displays enhanced transfection activity .