Evaluation Of Novel Cationic Liposomes As Micromolecule Drug And Gene Cotransport Vectors

Recent years,the lethality of tumor mortality remains a high level that people did not find an effective and controllable method,tumor treatment is the problem that people have been concerned about.Both chemotherapy and gene therapy,have the phenomenon of the curative effect is not obvious,or have side effects.Using cationic liposome as a non viral vector of chemotherapy and gene therapy has good prospects.To synthesize a novel cationic lipid N,N-dimethyl-(N',N'-di-(stearoyl-1-ethyl))1,3-diaminopropane(DMSP)and evaluate its feasibility as cationic lipid membrane material.With methotrexate(MTX)as model drug,the cationic liposome on the transdermal promoting effect of MTX and increasing the cell growth inhibitory effect of MTX.Antisense oligonucleotides F-ODN with green fluorescent markers and green report gene pDNA was used to evaluate the uptake and transfection of cationic liposomes.Co-delivery of signal transducer and activator of transcription 3(STAT3)RNA(siRNA)and MTX in to the cationicliposomes,to study tumor cell growth inhibition rate.Dimethylamine,1,3-bromine chloride,diethylamine and stearic acid as raw materials,DMSP was synthesized by 3 steps.DMSP and phosphatidylcholine was employed to produce liposomes by reverse phase evaporation method.The morphology of liposomes was observed under transmission electron microscope.The average diameter and Zeta potential were determined by laser particle size analyzer.Hemolysis was determined by red blood cell of rat.And then MTX was entrapped by physical mixing.The entrapment efficiency was determined by ultracentrifugation,and its release ratio was evaluated by dialysis.MTT was used to evaluate the cytotoxicity of liposomes as drug carrier and the inhibition of cancer cells growth.Fluorescent microscope was taken to evaluate cell uptake and transfection rate of genes,flow cytometry instrument was used to investigate tumor cell growth inhibition.The obtained liposomes showed regular shape and uniform size,with a mean Zeta potential of +(36.26 ± 4.77)mV and average diameter of 120 nm.The liposomes had low hemolytic activity and cytotoxicity.With the help of DMSP the cationic liposomes achieved to a very high entrapment efficiency of hydrophilic molecules MTX which could reach to(91.50 ± 1.02)%.The cationic liposomes containing cholesterol significantly improve the effect of gene transfection,which was much higher than commercial transfection reagent Lipofectamine?2000 with low toxicity by genetic experiments showed.Co-delivery with MTX and siRNA in cationic liposomes on tumor cell growth inhibitory effect was much higher than used alone MTX liposomes or SiRNA liposome.Liposomes prepared with DMSP were novel cationic liposomes with low cytotoxicity and high efficiency,which had a great potential for application in drug and gene delivery system.