Effect of Pluronic on cellular uptake of cationic liposomes- mediated antisense oligonucleotides

Cationic liposomes modified by different Pluronic block copolymers were prepared. The influence of Pluronic on the cellular uptake of antisense oligonucleotides (ODN) based on cationic 3betaN-(N', N'-dimethylaminoethan)-carbamoyl] cholesterol (DC-Chol) liposomes was studied by flow cytometric analysis. It showed that DC-Chol liposomes containing Pluronic gave 1.7-2.3 times higher capacity of cellular uptake of ODN, despite the diminution of ODN loading efficiency. The level of improvement by Pluronic is related to the hydrophobic propylene oxide (PO) units Pluronic contains as well as the lipophile/hydrophile value of the molecule. This preliminary study indicated that modifying liposomes with another excipient is a useful pharmaceutical technique to improve ODN delivery.