title: The use of chitosan as a condensing agent to enhance emulsion-mediated gene transfer.
abstract: Previously we have formulated a new cationic emulsion, composed of 3beta [N-(N',N'-dimethylaminoethane) carbamoyl] cholesterol and dioleoylphosphatidyl ethanolamine, castor oil and Tween 80, and it efficiently delivered plasmid DNA into various cancer cells with low toxicity. Chitosan is a natural cationic polysaccharide and is able to form polyelectrolyte complexes with DNA, in which the DNA is condensed and protected against nuclease degradation. Based on these facts, chitosan was used as a condensing agent to enhance the transfection efficiency of cationic emulsion-mediated gene delivery vehicle. The particle size, zeta potential and transmission electron micrographs of DNA/emulsion complexes were observed before and after condensation by chitosan. In vitro transfection efficiency of naked or precondensed DNA/emulsion (pcDNA/E) complexes was investigated in human hepatoma cells (HepG2) using flow cytometer, confocal microscope and western blot. In addition, in vivo gene transfer was also evaluated as GFP mRNA expression by reverse transcriptase-polymerase chain reaction. The size of transfection complexes was reduced after the condensation of DNA by chitosan. Moreover, when the pcDNA/E complexes were administered into the mice, the GFP mRNA expression was prolonged in liver and lung until day 6. These results suggest that the use of chitosan enhance the in vitro transfection efficiency and extend in vivo gene transfer.
authors.affiliation: National Research Lab for Drug and Gene Delivery, College of Pharmacy, Seoul National University, San 56-1, Shillim-dong, Kwanak-gu, Seoul 151-742, Republic of Korea.
authors.forename: Mi-Kyung
authors.initials: MK
authors.lastname: Lee
authors.forename: Soo-Kyung
authors.initials: SK
authors.lastname: Chun
authors.forename: Woo-Jeong
authors.initials: WJ
authors.lastname: Choi
authors.forename: Jin-Ki
authors.initials: JK
authors.lastname: Kim
authors.forename: Sung-Hee
authors.initials: SH
authors.lastname: Choi
authors.forename: Adele
authors.initials: A
authors.lastname: Kim
authors.forename: Kwunchit
authors.initials: K
authors.lastname: Oungbho
authors.forename: Jeong-Sook
authors.initials: JS
authors.lastname: Park
authors.forename: Woong Shick
authors.initials: WS
authors.lastname: Ahn
authors.forename: Chong-Kook
authors.initials: CK
authors.lastname: Kim
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D048271:Chitosan / Q000009:adverse effects / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000008:administration & dosage / Q000009:adverse effects / Q000737:chemistry; D016503:Drug Delivery Systems / Q000009:adverse effects / Q000379:methods*; D004655:Emulsions / Q000737:chemistry; D018014:Gene Transfer Techniques; D006801:Humans; D008297:Male; D008422:Materials Testing; D051379:Mice; D008807:Mice, Inbred BALB C; D010316:Particle Size; D010957:Plasmids / Q000008:administration & dosage* / Q000648:ultrastructure; D012995:Solubility; D014162:Transfection / Q000379:methods*
chemical_list: D020099:Coated Materials, Biocompatible; D004655:Emulsions; D048271:Chitosan