Gene Transfection And Biocompatibility Comparison Of Dendrimers With Four Kinds Of Amino-modified

Gene therapy is thought to be an important method to treat the disease in the future. And the gene therapy need efficient gene vector to delivery the DNA needed to the targeted location. Current gene delivery vectors can be dividedinto viral vectors and nonviral vectors.Viral vectors have problems such as safety concerns and difficulty in large scale industrial production.Nonviral genevector such as cationic polymer provides opportunities for improved safety and more facile manufacturing, but is usually criticized for low transfection efficacy.Therefore, it’s important to build high efficient and safe gene vectors. In this paper, we study to build gene carrier on the basis of PAMAM dendrimer,we discuss gene transfection efficiency of G5PAMAM when it has amino acids functionalized modification.We synthesized G5PAMAM modified by arginine, lysine, histidine and phenylalanine,they were characterized by NMR techniques,according to the number of connections.products were labeled G5-Arg64. G5-Arg110、G5-His40、G5-His113、 G5-Phe71、G5-Phe99、G5-Lys130; G5-Arg64、G5-Arg110、G5-His40、G5-His113、 G5-Phe71can completely composite plasmid DNA, form stable complexes at N/P=2,G5-Phe71、G5-Phe99can completely composite plasmid DNA, form stable complexes at N/P=4;then transfected Luciferase, EGFP plasmids to HeLa and293T cells, and compared the transfection efficiency of these materials. The results showed that the Luciferase plasmidtransfection efficiency of the G5-Arg110is higher than G5-Arg64,the transfection efficiency of G5-Arg64、G5-Arg110increased about10times, obviously promoted the Luciferase plasmid transfection efficiency on HeLa and293T cells,; the transfection efficiency has no obvious difference between G5-Lys130and the G5PAMAM; the Luciferase plasmid transfection efficiency of G5-His40、G5-His113、G5-Phe71、G5-Phe99were significantly lower than G5PAMAM.We also used the EGFP plasmid to transfect HeLaand293T cells,We found similar results,arginine modification can significantly improve the G5PAMAM transfectionefficiency, otheramino acids modifications improve ineffectively. Then we used MTT assay to detect the cell toxicity of four amino acid modifications G5PAMAM on HeLa and293T cells, the results showed that G5PAMAM and amino acids modified G5PAMAM at the optimal N/P ratio have non-toxic side effects on the HeLa and293T cells, the cell survival rates were over90%and cells were in good condition.Based on these results we detect the side effects of these materials which were not in combination with DNA on HeLa and293Tcells, the results showed that the cytotoxicity of G5-His40、G5-His113、 G5-Arg64、G5-Arg110、G5-Lys130is lower than G5PAMAM,the cytotoxicity of G5-Phe71、G5-Phe99is higher than G5PAMAM.In summary, the transfection efficiency of G5-Arg64、G5-Arg110is higher,and cytotoxicity decreased,improved the biocompatibility of G5PAMAM;G5-Lys130decreased the cytotoxicity,improved the biocompatibility of G5PAMAM,but decreased the transfection efficiency;G5-His40、G5-His113obviously decreased the cytotoxicity,improved the biocompatibility of G5PAMAM,but decreased the transfection efficiency;G5-Phe71、G5-Phe99increased the cytotoxicity,decreased the biocompatibility of G5PAMAM,and also decreased the transfection efficiency.