Cationic gemini lipids with cyclen headgroups: interaction with DNA and gene delivery abilities

A series of novel 1,4,7,10-tetraazacyclododecane (cyclen)-based gemini cationic lipids were synthesized, and L-cystine was used as backbone between the two amphiphilic units. The liposomes formed from the lipids and DOPE could efficiently condense plasmid DNA into nanoparticles with suitable size and zeta-potentials, which might be suitable for gene transfection. These lipids were applied as non-viral gene delivery vectors, and their structure-activity relationship was studied. It was found that both the hydrophobic tails and the linking group could largely influence the transfection efficiency, and the oleylamine derived lipid gave the best transfection results, which were close to the commercially available transfection reagent lipofectamine 2000. The gemini structure would favor the gene transfection, and the transfection efficiency of the gemini lipid was much higher than the mono counterpart. Besides, these lipids have very low cytotoxicity, suggesting their good biocompatibility. Results indicate that such gemini lipids might be promising non-viral gene delivery vectors.