title: In vitro gene delivery to HepG2 cells using galactosylated 6-amino-6-deoxychitosan as a DNA carrier.
abstract: A chitosan derivative, 6-amino-6-deoxy chitosan (6ACT), was galactosylated and was investigated as a gene carrier. A series of galactose-modified 6ACT (Gal-6ACT) with degrees of substitution (d.s.) ranging from 3% to 50% per pyranose were prepared by reductive alkylation with lactose. DNA retardation assays showed that the electrostatic interaction between Gal-6ACT and plasmid DNA was not changed by galactose modification up to 50% per pyranose of 6ACT. Gal-6ACT with a d.s. of 38% was bound to galactose-recognizing lectin, RCA120. A significant increase in transfection efficiency for HepG2 cells was observed at degree of substitutions ranging from 18% to 50% and at N/P values ranging from 1.5 to 2.5. Under optimum conditions, Gal-6ACT showed about 10 times higher efficiency than 6ACT. However, a slight uptake by the galactose receptors on hepatocytes was observed by flow cytometric analysis. Moreover, Gal-6ACT with a d.s. of 38% mediated efficient gene transfer into both A549 and HeLa cells lacking the galactose receptor. These results suggest that the enhancement of transfection efficiency of Gal-6ACT was not due to the increase of receptor-mediated cellular uptake. In addition, the enhanced gene transfer efficiency was not specific to the galactose modification because the efficiency of glucose-modified 6ACT for HepG2 cells was similar as that of Gal-6ACT.
authors.affiliation: Department of Applied and Bioapplied Chemistry, Graduate School of Engineering, Osaka City University, Sumiyoshi, Osaka 558-8585, Japan. satoh@bioa.eng.osaka-cu.ac.jp
authors.forename: Taku
authors.initials: T
authors.lastname: Satoh
authors.forename: Shinji
authors.initials: S
authors.lastname: Kakimoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kano
authors.forename: Mika
authors.initials: M
authors.lastname: Nakatani
authors.forename: Seiji
authors.initials: S
authors.lastname: Shinkai
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nagasaki
mesh_terms: D000818:Animals; D019556:COS Cells; D006528:Carcinoma, Hepatocellular / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D048271:Chitosan / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D002522:Chlorocebus aethiops; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D004337:Drug Carriers; D005690:Galactose / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008113:Liver Neoplasms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: C517097:6-amino-6-deoxy-chitosan; D004337:Drug Carriers; D004247:DNA; D048271:Chitosan; D005690:Galactose