Synthesis Of Quaternized DoGo Lipids And Study Of Their Transfection Efficiency

The primary problem to be solved in gene therapy is how to effectively import the target gene into the cell of diseased tissue and make it express safely and efficiently.The non-viral vector has a wide application prospect due to its low toxicity,high safety,easy preparation,ability to carry larger DNA among other advantages.Cationic liposomes have very a wide application in non-viral vector.In this paper,DoGo1 was used as the basic material,which was synthesized by the amination reaction between Boc-L-glutaminic acid and oleylamine and subsequent deprotection reaction.Do Go31 and Do Go211 were prepared by the amination reaction,deprotection reaction and quaternization reaction of the hydrophilic head group of Do Go1.We determined the molecular weight and structure of compounds by characterization of mass spectrum(MS)and ~1HNMR.We determined the uniformity and electrificated situation of the compounds,and whether it can be used in transfection experiments by the test of laser particle size analyzer and zeta potential.The biological activities of the compounds were confirmed by experiments of agarose gel electrophoresis,cytotoxic and cell transfection.The experiment was compared with the other high-efficiency lipid molecules synthesized in our laboratory.The experimental results showed that the mixture of this compounds with different auxiliary lipids have different transfection efficiency.In summary,based on the structure of lipid molecule DoGo4,which was synthesized highly efficiently in this experiment,quaternary modification was performed on its amino group to synthesize two compounds with different positions of quaternary ammonium salt.Structure of compounds were confirmed by using MS and ~1HNMR.This paper provides foundation and basis for the experimental study of the modification of cationic lipid molecules.