Introduction of cyclic guanidines into cationic lipids for non-viral gene delivery

In order to study the impact of chemical modifications of lipopolyamines on their gene delivery properties, we have introduced cyclic guanidines into the polyamine moiety. These lipopolyamino-cycloguanidines can be easily obtained by reacting polyamines with 2-methylmercapto-2-imidazolinium iodide or 2-methylmercapto tetrahydropyrimidinium iodide. These lipopolyamino-cycloguanidines constitute a novel family of cationic lipids.