title: Synergistic effect of poly(ethylenimine) on the transfection efficiency of galactosylated chitosan/DNA complexes.
abstract: The use of chitosan for gene delivery is limited due to the low transfection efficiency and difficulty in transfecting into a variety of cell types, especially the hepatoma cells. In order to solve this problem, lactobionic acid (LA) bearing galactose group was coupled with water-soluble chitosan (WSC) for liver specificity and poly(ethylenimine) (PEI) was combined to galactosylated chitosan (GC)/DNA complexes to enhance the transfection efficiency. For initial study, the effect of PEI on the transfection efficiency of WSC/DNA complex was studied in HeLa, A549 and 293 T cells, and bafilomycin A1 was used to ascertain the mechanism of synergistic effect. Transfection efficiency, cytotoxicity, and physicochemical properties of GC/DNA complex combined with PEI were investigated to determine the potential for the hepatocyte-targeting. The combination of PEI with WSC/DNA and GC/DNA complex dramatically increased the luciferase expression 10- to 1000-fold in various cell lines, and the synergistic effect was proved to be induced by proton sponge effect of PEI. The transfection of GC/DNA complex in HepG2 was much higher than that of WSC/DNA even after combination with PEI, and was highly inhibited in the presence of galactose. Cytotoxicity of PEI was much decreased by combination with GC/DNA complex. And PEI was proved to be coated on the surface of GC/DNA complex through the ionic interaction.
authors.affiliation: School of Agricultural Biotechnology, Seoul National University, Seoul 151-742, South Korea.
authors.forename: Tae Hee
authors.initials: TH
authors.lastname: Kim
authors.forename: Su Il
authors.initials: SI
authors.lastname: Kim
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Akaike
authors.forename: Chong Su
authors.initials: CS
authors.lastname: Cho
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D048271:Chitosan / Q000494:pharmacology*; D004247:DNA / Q000008:administration & dosage* / Q000737:chemistry / Q000235:genetics; D004187:Disaccharides; D004357:Drug Synergism; D004587:Electrophoresis, Agar Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry; D005690:Galactose / Q000494:pharmacology*; D017930:Genes, Reporter / Q000235:genetics; D006801:Humans; D008099:Liver / Q000378:metabolism; D008156:Luciferases / Q000235:genetics; D018942:Macrolides / Q000494:pharmacology; D018613:Microscopy, Confocal; D010316:Particle Size; D011094:Polyethyleneimine / Q000494:pharmacology*; D014162:Transfection
chemical_list: D004187:Disaccharides; D004791:Enzyme Inhibitors; D018942:Macrolides; C005608:lactobionic acid; C040929:bafilomycin A1; D011094:Polyethyleneimine; D004247:DNA; D048271:Chitosan; D008156:Luciferases; D005690:Galactose