Effect of cationic liposomes on intracellular trafficking and efficacy of antisense oligonucleotides in mouse peritoneal macrophages.
We have investigated the intracellular fate and antisense effect of oligonucleotide/cationic liposome complexes using phosphorothioate oligonucleotides (S-Oligo) targeted to inducible nitric oxide synthase in mouse peritoneal macrophages. Confocal laser microscopic analysis revealed that, after application of fluorescein isothiocyanate (FITC)-labeled S-Oligo alone, the intracellular localization of fluorescence exhibited a punctate pattern in the cytoplasm, suggesting that the oligonucleotides were mainly confined to the endosomal and/or lysosomal compartments. In the case of complexation with Lipofectin and DMRIE-C liposomes, cellular uptake of FITC-S-Oligo was not greatly enhanced and the fluorescence localization in the cells was similar to that of FITC-S-Oligo alone. LipofectAMINE slightly enhanced cellular uptake of FITC-S-Oligo; however, the intracellular localization profile of FITC-S-Oligo remained largely unchanged. The antisense effect was slightly enhanced by LipofectAMINE under only very limited experimental conditions. It was concluded that cationic liposomes are not a potential carrier for S-Oligo in peritoneal macrophages because of their inability to promote the release of S-Oligo from the endosomal compartments to the cytosol over a non-toxic concentration range.
Takagi
T
T
Department of Drug Delivery Research, Graduate School of Pharmaceutical Sciences, Kyoto University, Japan.
Hashiguchi
M
M
Hiramatsu
T
T
Yamashita
F
F
Takakura
Y
Y
Hashida
M
M
D000818:Animals; D002478:Cells, Cultured; D004337:Drug Carriers; D008081:Liposomes / Q000008:administration & dosage*; D017737:Macrophages, Peritoneal / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009569:Nitric Oxide / Q000096:biosynthesis; D016376:Oligonucleotides, Antisense / Q000008:administration & dosage* / Q000493:pharmacokinetics
D004337:Drug Carriers; D008081:Liposomes; D016376:Oligonucleotides, Antisense; D009569:Nitric Oxide