| Gene therapy has been a new approach in cancer therapy through clinical research,but selecting a safe and efficient carrier is always the key problem.Cationic liposomes have the characteristics of low toxicity,well biocompatibility,easy preparation,which have been paid great attention.Therefore,cationic liposomes as gene carrier have a very broad application.In this paper,arginine-glycine-aspartic(RGD)tripeptide was synthesized by the method of solid-phase,and the RGD peptide cationic lipid was obtained by connecting with the intermediate A14.After separating and purifying,product with 95%HPLC purity a was given.The product was characterized by ESI-MS,IR and ~1H NMR.Then the cationic liposomes were prepared by the film-ultrasonic method with the synthesized RGD peptide cationic lipid.And TEM and Nanoparticle Analyzer were used to research these liposomes.It was found that the liposomes were spheres with the average size of 50 nm and zeat potential of 80 mV.The agarose gel electrophoresis was used to research DNA binding ability with cationic liposomes.It was showed that cationic liposomes and DNA were capable of forming the complexs.And the binding capacity between liposomes and DNA increased when the liposome/DNA ratio increased.In addition,co-lipid DOPE could be added to improve the binding capacity of liposomes and DNA.The gene delivery of plasmid DNA pGFP-N2 was tested on Hela cells.The results showed there was an optimum N/P ratio of 3/1 for transfection.The transfection efficiency was improved when co-lipid DOPE was added.The cell cytotoxicity was analyzed by the MTT assay and it was showed that RGD peptide cationic liposomes were less cytotoxic,the cell viability was above 80%.And some showed higher cell viability than commercial reagents Lipofectamine 2000 and DOTAP. |
