Design And Synthesis Of Cationic Lipids And The Study On Their Biological Performance

2 series of cationic lipids were designed, synthesized and purified. The prepared 40 compounds, most of which are new compounds, were all characterized correct by IR, ¹H NMR, ¹³C NMR, HRMS or MS, which can be used for gene delivery.The synthesized cationic lipids were prepared into cationic liposomes. Some preliminary discipline for the structure-effect relationship between the cationic lipids structure and the liposomes formed could be abstracted by means of TEM, dynamic light scattering and zeta-potential measurement. The prepared cationic liposomes can form with plasmid DNA into liposome/DNA complex, which can be characterized by agarose gel electrophoresis.Two plasmid DNA pGL3-control and pGFP-N2 were used to transfect 5 mammal cell lines, COS-7, Hep-2 B16, MCF-7 and Hepal-6, by means of the above liposomes as gene carrier, and the prepared cationic liposomes can deliver DNA into cells successfully. By using two commercial transfection agent Lipofectamine2000 and Sofast as controls, some of the above cationic liposomes give a superior performance than the controls. 6 liposomes then be selected, which are promising for further application. Cytotoxicity test by MTT give a satisfactory result for the selected 6 cationic lipomes.Also in the dissertation, the affect of the cationic heads, the hydrophobic carbon tails, the linker between them, as well as the balance anion on the transfection efficiency were discussed, some preliminary conclusion be drawn form the discussion.