Preparation Of Gene Drug Delivery Systems Of Cationic Peptide Lipid 0G-PAMAM As Hydrophilic End And Its Biological Properties Evaluation

Gene therapy is transferred the target genes into the patient’s somatic cells,expression,achieves the disease treatment the goal. So far,it is more than 1800 gene therapy clinical trials approved in the worldwide,however,to this day the gene therapy failed to achieve a breakthrough.At present,the carrier of gene therapy mainly has two types which is viral vector and non viral vector. While the type of virus carrier(such as retrovirus,adenovirus vector,herpes simplex virus vector,etc.) has high transfection efficiencies,but it has some security issues,such as potential toxicity and immunogenicity,mutagenicity,at the same time it is hard production and limited contained ability of exogenous DNA contained,etc. Which is limited making its application.according to the survey that two out of nine patients will cause leukemia after using high transfection efficiency retrovirus vector; Non virus carrier includes cationic polymers and cationic liposomes,which is the latest gene carrier development and important supplement,it has high trapping efficiency,low immunogenicity,security,strong targeting and can batch production,etc,it has become a research hotspot at home and abroad.peptide lipid is a kind of amphiphilic properties compounds,the amide bond hydrophilic head is formed by amino end acylation of amino acid,the hydrophobic tails is form by carboxyl end with long carbon chain amino compounds through dehydrated. The polar head plays a role of liposom complexes with DNA,liposome- DNA complex with cell membrane or combined with other components within the cell,the join keys determines the stability and biodegradability of Cationic lipid. The PAMAM end groups can be precisely controlled,As drug and gene carrier which has high stability and excellent biological compatibility,non-immunogenicity,the 0 generation PAMAM have dendritic structure virtues and non-toxic.Lauric acid,also known as Lauric acid,is a saturated fatty acids,it is lower than other saturated fatty acids in cardiovascular disease risk. This cationic lipid use double Lauric acid as hydrophobic chain. The cationic hydrophobic tail main function is to provide sufficient liquidity to lipid bilayers and maintain the lipid bilayers membrane rigidity,so as to create conditions for cationic liposomes with vivo lipids fusing; L- tartaric acid(2,3-dihydroxy succinic acid) is a carboxylic acid,non-toxic and good biocompatibility; Lysine is one of the essential amino acid,non-toxic and good biocompatibility,which can promote human development,enhance immune function,inhibit herpes simplex virus replication and can preventive angina pectoris,myocardial infarction,and liver disease.With double lauric acid as hydrophobic chains,tartaric acid as skeleton,lysine modified 0 generation PAMAM as hydrophilic head,synthetic new type cationic peptide lipid. The alkyl chain is promote lipid across cell membranes and with membrane fusion,lysine modified 0 generation PAMAM hydrophilic end amino can contain a large number of protons which can is changed into ammonium and combined with the DNA negatively charged phosphate groups.It is expected that this carrier has low toxicity,high transfection efficiency and targeting property. By adjusting the cationic liposome/gene weight ratio to optimize the transmission system,improved gene transfection efficiency,reduce cytotoxicity,and increase property and stability,etc.The research contents are as follows:(1)Synthesis of Lauric acid acyl tartaric acid lipid-PAMAM-Lys:We have used the twelve acyl chloride,tartaric acid,0 generation PAMAM,lysine as raw material,choose a suitable solvent preparation of cationic lipid,and the chemical structure of synthetic product was confirmed by IR and 1HNMR.(2) We used the results of the cationic lipid formed different weight ratio with DNA in water,measured the determination of particle size and Zeta potential and performed gel retardation assay.In the study,we fond that after the Lauric acid acyl tartaric acid lipid-PAMAM-Lys liposomes interact with DNA,the size within to 200 nm and forming dense nanoparticles and well dilution stability.(3)The cytotoxicity was exploration by MTT in different cells. The Double lauric Acid Tartaric Acid Ester Cationic Lipid cytotoxicity is lower than 25 k PEI and liposome 2000,(4)The transfection efficiency was measured in different cells related to the concentration of the cationic lipid,but the transfection efficiency is lower than liposome 2000.