Abstract:

BACKGROUND: Cationic liposomes and transgenic vectors such as micelles and nanoparticles, is a current research focus of non-viral transgenic vector; currently commercial transgenic kits are expensive and basically imported goods, it is increasing urgent to develop a cheap, efficiently transgenic kit with independent intellectual property rights for broad market prospects.
OBJECTIVE: To synthesize a new cationic lipid composite and prepare cationic liposome, to investigate its transgenic efficiency in vitro.
METHODS: The cationic lipid composite was synthesized by organic chemistry synthesis method using EDCI, cholesterol, succinic anhydride as raw materials; the structure characterization of the products was validated through thin-layer chromatography and infrared spectrum technique. A new cationic liposome was prepared with proper proportion of 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine and cationic lipid composite, and was used to envelop eukaryotic expression plasmid pEGFPC1 containing green fluorescent protein report gene, and then its gene transfection efficiency on human cervical carcinoma Hela cell in vitro was detected.
RESULTS AND CONCLUSION: A new cationic lipid composite, Cholesterol-Succinate-EDCI, was obtained with two step methods; thin-layer chromatography and infrared spectrum confirmed it as the expect product. The liposome were prepared by film dispersion method with 1:1 molar ratio of Cholesterol-Succinate-EDCI: 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine, the liposome granules were tiny, spherical shaped and well-distributed. In vitro plasmid enveloping experiment showed that, this liposome can completely envelop plasmid and form lipoplex with the mass ratio 5:3. In vitro gene transfer essay indicated that the lipoplex transient transfection efficiency can reach 35.6% after treatment with 24 hours. The prepared cationic lipid composite structure is similar to commercially positive component structure, the synthesis method is simple and cheap, it can effectively envelop the plasmid DNA in vitro, with low toxicity, however, in vitro transfection efficacy of Hela cells remains low.