Asialoglycoprotein receptor-mediated gene transfer using novel galactosylated cationic liposomes.
We synthesized three novel galactosylated cholesterol derivatives, cholesten-5-yloxy-N-(4-((1-imino-c-beta-D-thiogalactosyl+ ++-ethyl)amino) butyl)formamide (Gal-C4-Chol) and its ethyl formamide and hexyl formamide analogues (Gal-C2-Chol, Gal-C6-Chol), to prepare liposomal gene carriers possessing the cationic charge necessary for plasmid DNA binding and galactose residues as a targetable ligand for liver parenchymal cells. Liposome/DNA complexes prepared with these lipids showed low cytotoxicity in human hepatoma HepG2 cells. Gal-C4-Chol/DC-Chol/DOPE(3:3:4) liposomes, consisting of 3:3:4 mixtures of Gal-C4-Chol, 3beta[N',N', N'-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol), and dioleoylphosphatidylethanolamine (DOPE), showed higher transfection activity and [32P]DNA uptake than DC-Chol/DOPE(6:4) liposomes. The presence of 20 mM galactose significantly inhibited both transfection efficiency and uptake of DNA of Gal-C4-Chol/DC-Chol/DOPE(3:3:4) and Gal-C4-Chol/DOPE(6:4) liposomes, but not those of DC-Chol/DOPE(6:4) liposomes. These results indicate that the liposome/DNA complexes prepared using novel galactosylated cholesterol derivatives are efficiently recognized by asialoglycoprotein receptors and internalized and lead to gene expression. In addition, we found that the galactosylated cholesterol derivative with a longer spacer showed higher transfection activity.
Kawakami
S
S
Department of Drug Delivery Research, Graduate School of Pharmaceutical Sciences, Kyoto, Sakyo-ku, 606-8501, Japan.
Yamashita
F
F
Nishikawa
M
M
Takakura
Y
Y
Hashida
M
M
D016475:3T3 Cells; D000818:Animals; D037263:Asialoglycoprotein Receptor; D006528:Carcinoma, Hepatocellular; D002470:Cell Survival; D002784:Cholesterol / Q000031:analogs & derivatives; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004337:Drug Carriers; D005690:Galactose; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006801:Humans; D008081:Liposomes; D008113:Liver Neoplasms; D051379:Mice; D010957:Plasmids / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000502:physiology*; D014162:Transfection / Q000379:methods*; D014407:Tumor Cells, Cultured
D037263:Asialoglycoprotein Receptor; D004337:Drug Carriers; D008081:Liposomes; D011956:Receptors, Cell Surface; D004247:DNA; D002784:Cholesterol; D005690:Galactose