Effects of PEG anchors in PEGylated siRNA lipoplexes on in vitro gene‑silencing effects and siRNA biodistribution in mice.

Polyethylene glycol (PEG)‑modifications (PEGylations) of cationic liposome/small interfering RNA complexes (siRNA lipoplexes) can enhance their systemic stability. The present study determined the effects of PEG anchors in PEGylated siRNA lipoplexes on in vitro gene‑silencing effects and siRNA biodistribution after intravenous injection. Three types of dialkyl or trialkyl cationic lipids were used in the current study for the preparation of cationic liposomes.

Effect of cationic lipid in cationic liposomes on siRNA delivery into the lung by intravenous injection of cationic lipoplex.

Cationic liposomes composed of dialkyl cationic lipid such as 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) can efficiently deliver siRNA to the lungs following the intravenous injection of cationic liposome/siRNA complexes (lipoplexes). In this study, we examined the effect of cationic lipid of cationic liposomes on siRNA delivery to the lungs after intravenous injection. We used six kinds of cationic cholesterol derivatives and 11 kinds of dialkyl or trialkyl cationic lipids as cationic lipids, and prepared 17 kinds of cationic liposomes composed of a cationic lipid and 1,2-dioleoyl-L-α-glycero-3-phosphatidylethanolamine (DOPE) for evaluation of siRNA biodistribution and in vivo gene silencing effects.