STUDY ON THE TRANSFECTION EFFICIENCY OF ANTISENSE OLIGODEOXYNUCLEOTIDE AGAINST TELOMERASE BY CATIONIC FUSOGENIC LIPOSOME

AIMTo investigate the factors affecting transfection efficiency of antisense oligodeoxynucleotides (ASON) by cationic fusogenic liposome (CFL). METHODSThree types of cationic liposomes (CL) were prepared by reverse-phase evaporation vesicles and cationic fusogenic liposomes (CFL) were obtained through fusion with Sendai virus. The CFL/ASON complexes were formed by physical absorption. Transmission electron microscope was used to observe its morphology. Drug loading capacity was examined by Nanosep centrifuge tube. The cellular damage of two vectors was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Transfection efficiency was estimated with the use of fluoresein phosphoramidite (FAM)-antisense oligodeoxynucleotides by flow cytometric analysis. RESULTSThe mean diameter of CL and CFL was (124±19) nm and (168±65) nm, respectively. The drug loading capacity was depended on the charge of the ratio of lipid/ASON (+/-) and the cationic charge density on the lipid membrane. The cellular damage of CFL was obviously inferior to the same lipid/ASON (+/-) charge ratio of CL. The fluorescence intensity was shown to enhance the content of 3β-［N-(N′,N′-dimethylaminoethane) carbamoyl］ cholesterol (DC-Chol) and lipid/ASON (+/-) charge ratio. However, the transfection efficiency mediated by CFL at low lipid/ASON (+/-) charge ratio increased about two fold than that by CL. Later, both serum and temperature affect the capacity of cellular uptake by CL or CFL. The effect of the transfection efficiency using CFL was much weaker. CONCLUSIONCationic fusogenic liposome (CFL) improved transfection efficiency and decreased cellular damage at the condition of low lipid/ASON (+/-) charge ratio. So, the vector need further study as ASON delivery system.