Synthesis And Performance Study On Cationic Gene Vector Linked By Carbamate

Gene therapy has bright prospect in treating the diseases that can't be cured by conventional method, such as cancer, parkinsonism syndrome, leukemic and AIDS. Its efficiency has been verified in clinical study. A proper gene vector is the key in determining whether gene therapy is successful or not. Both the viral vector and non-viral vector have their disadvantages in transfection efficiency and cytotoxicity. The research of chemistry and life science has focused on searching a gene vector with high efficiency and low toxicity.In this paper, a kind of cationic lipid linked by carbamate has been designed and synthesized, and the synthesis process has been optimized too. All of the intermediates and final products have been characterized by ~1H NMR, MS, their purity can meet the requirement of transfection. We have got the values of cmc, HLB, P and T_m of cationic lipids 3a and 3b by doing the measurements or the theory calculations.Cationic liposome has been synthesized by the cationic lipid in this paper and the liposome status has been studied by TEM and ZETASIZER nano series Nano-ZS90. And then the influences of the concentration, preparation temperature and critical arrangement parameter to the liposome status have been investigated and here are some rules: The diameter and Zeta potential are increased with the increase of the concentration of lipids; in the range of T_m, with the increase of the preparation temperature, the diameter and PDI are decreasing, while the Zeta potential is increased; under the same preparation conditions, liposomes prepared by 3a and 3b have similar diameters. The smaller the critical arrangement parameter is, the larger Zeta potential is. The feasibility of preparing mixed liposome by cationic liposome 3a and the nonionic fluorescent surfactant F has also been discussed in this paper.With the cationic lipid 3a and 3b used as the gene vector, DNA plasmid pGFP-N2 and pGL3-control were transfected into cell line COS-7, Hep-2 and Hepal-6. Comparing the transfection efficiency and cytotoxicity with two commercial gene vectors Lipofectamine2000 and Sofast, it is proved that the application prospect of cationic lipid 3a in gene therapy is very bright.To solve the problem of the cationic lipid 3a with its low transfection efficiency in mouse hepatocyte Hepal-6, two kinds of cationic lipid 4a, 4b and 5a, 5b linked by hepatic targeting ligand galactose were designed in this paper. The exploration of their synthesis provides some references to the subsequent research.