The use of chitosan as a condensing agent to enhance emulsion-mediated gene transfer.
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.
Lee
Mi-Kyung
MK
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.
Chun
Soo-Kyung
SK
Choi
Woo-Jeong
WJ
Kim
Jin-Ki
JK
Choi
Sung-Hee
SH
Kim
Adele
A
Oungbho
Kwunchit
K
Park
Jeong-Sook
JS
Ahn
Woong Shick
WS
Kim
Chong-Kook
CK
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*
D020099:Coated Materials, Biocompatible; D004655:Emulsions; D048271:Chitosan