Effect of cationic liposome composition on in vitro cytotoxicity and protective effect on carried DNA

Positively charged liposomes were prepared by using three different cationic surfactants, namely cetyl-trimethyl-ammonium bromide (CTAB), didodecyl-dimethyl-ammonium bromide (DDAB(12)) and dioctadecyl-dimethyl-ammonium bromide (DDAB(18)). A study of the parameters influencing the in vitro toxicity of cationic liposomes on cultured cell lines was performed, demonstrating the lower cytotoxicity of DDAB(18)-containing liposomes. In addition, the stability of lambda DNA complexed to cationic liposomes after exposure to serum exo- and endonucleases was evaluated. Our results indicated that DDAB(12) and DDAB(18) liposomes are able to efficiently protect DNA from degradation, thus representing a potential approach to deliver nucleic acid in vivo.