A cationic lipid emulsion/DNA complex as a physically stable and serum-resistant gene delivery system.
OBJECTIVE
To develop a non-viral gene delivery system in the form of an oil-in-water (o/w) lipid emulsion.


METHODS
Cationic lipid emulsions were formulated with soybean oil, 1,2-dioleoyl-sn-glycero-3-trimethylammonium-propane (DOTAP) as a cationic emulsifier and other co-emulsifiers. The physical characteristics of the lipid emulsion and the emulsion/DNA complex were determined. The in vitro transfection efficiency of the emulsion/DNA complex was determined in the presence of up to 90% serum.


RESULTS
The average droplet size and zeta potential of emulsions were ca. 180 nm and ca. +50 mV, respectively. Among the emulsions, a stable formulation was selected to form a complex with a plasmid DNA encoding chloramphenicol acetyltransferase. By increasing the ratio of emulsion to DNA. zeta-potential of the emulsion/DNA complex increased monotonously from negative to positive without any changes in the complex size. The complex was stable against DNase I digestion and an anionic poly-L-aspartic acid (PLAA). The complex delivered DNA into the cells successfully, and the transfection efficiency was not affected by complex formation time from 20 min to 2 h. More importantly, the cationic lipid emulsion facilitated the transfer of DNA in the presence of up to 90% serum.


CONCLUSIONS
The cationic lipid emulsion/DNA complex has physical stability and serum resistant properties for gene transfer.
Yi
S W
SW
Biomedical Research Center, Korea Institute of Science and Technology, Seoul.
Yune
T Y
TY
Kim
T W
TW
Chung
H
H
Choi
Y W
YW
Kwon
I C
IC
Lee
E B
EB
Jeong
S Y
SY
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D001798:Blood Proteins / Q000494:pharmacology*; D019556:COS Cells; D002412:Cations / Q000493:pharmacokinetics; D002795:Choline O-Acetyltransferase / Q000235:genetics; D003851:Deoxyribonucleases; D004586:Electrophoresis; D004655:Emulsions; D018014:Gene Transfer Techniques; D005990:Glycerol / Q000493:pharmacokinetics; D010455:Peptides; D010957:Plasmids; D011092:Polyethylene Glycols / Q000493:pharmacokinetics*; D013024:Soybean Oil / Q000493:pharmacokinetics*; D014162:Transfection; D014867:Water
D001798:Blood Proteins; D002412:Cations; D004655:Emulsions; D010455:Peptides; D014867:Water; C017645:polyaspartate; D011092:Polyethylene Glycols; D013024:Soybean Oil; D002795:Choline O-Acetyltransferase; D003851:Deoxyribonucleases; D005990:Glycerol