title: Improved gene expression pattern using Epstein-Barr virus (EBV)-based plasmid and cationic emulsion.
abstract: To improve transgene expression of a non-viral gene delivery system, an Epstein-Barr virus (EBV)-based plasmid and cationic emulsion complex was prepared and evaluated. Cationic emulsion was formulated with castor oil, 3-N-(N',N'-dimethylaminoethane)-carbamoyl cholesterol (DC-Chol) and other co-emulsifiers. An EBV-based plasmid containing the two EBV components, origin of replication (oriP) and EBV nuclear antigen 1 (EBNA-1), was constructed. The physical characteristics of the emulsion and the emulsion/DNA complex were determined. After cells were transfected with cationic emulsion/EBV-based plasmid complex, transfection efficiency and expression pattern were evaluated using green fluorescent protein (GFP) as a reporter. The average particle size and zeta potential of the emulsion itself were 96 nm and + 17 mV, respectively. The emulsion showed stable size distribution up to at least one month. With an increase of emulsion to DNA ratio, zeta-potential increased from negative to positive and the particle size decreased to 200-300 nm. The complex was stable against DNase I digestion and showed comparable transfection efficiency with Lipofectin for several tested cell lines. An enhanced and prolonged gene expression was achieved using EBV-based plasmid and cationic emulsion complex. Combining physically stable emulsion with self-replicating EBV-based plasmid may confer more effective gene expression.
authors.affiliation: Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, San 56-1, Shillim-dong, Kwanak-gu, Seoul 151-742, Republic of Korea.
authors.forename: Kyoung Ah
authors.initials: KA
authors.lastname: Min
authors.forename: Suk Kyeong
authors.initials: SK
authors.lastname: Lee
authors.forename: Chong-Kook
authors.initials: CK
authors.lastname: Kim
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D002368:Castor Oil / Q000737:chemistry; D002412:Cations; D045744:Cell Line, Tumor; D002784:Cholesterol / Q000737:chemistry; D004279:DNA, Viral / Q000008:administration & dosage* / Q000235:genetics*; D016503:Drug Delivery Systems / Q000379:methods*; D004655:Emulsions; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics; D014162:Transfection / Q000379:methods*
chemical_list: D002412:Cations; D004279:DNA, Viral; D004655:Emulsions; D002368:Castor Oil; D002784:Cholesterol