Targeted Gene Therapy Using Magnetic Cationic Liposomes for Osteosarcoma

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To control the growth of primary tumors effectively, we recently invented intravenously administered magnetic liposomes, which could be effectively delivered to solid tumors where a permanent magnet was implanted. Furthermore, we developed magnetic cationic liposomes as a nonviral vector to facilitate efficient DNA mediated transfection for targeted gene therapy.Preparation of magnetic cationic liposomes : A mixture of 18 μmol 3 βN-(N'N'-dimetylaminoetane)-carbarmoyl cholesterol (DC cholesterol) and 12 μmol of dioleoil phosphatidylethanol amine (DOPE) in chloroform were evaporated by a rotary evaporator and resuspended in 1 ml sterile buffer (pH7.4) containing 10 mg magnetite particles. After hydration for 24 hours at 4℃, the organic solvent was sonicated for 10 minutes in a bath sonicator.In vitro study : To observe the expression of transfected gene with magnetic cationic liposomes, a reporter gene containing β-galactosidase gene, pCMV SPORT-β gal was used, pCMV SPORT-β gal (100μg) was complexed with magnetic cationic liposomes in increasing ration of 10 : 1, 1 : 1, 1 : 5, and 1 : 10. The mixture was added to osteosarcoma cells (Os515) in incubation medium and osteosarcoma cells were harvested -18 hours after the incubation at 37C.The expression of pCMV SPORT-β gal was observed by western blotting in the ratio of 5 : 1 and 10 : 1.Magnetic cationic liposomes efficiently mediated the gene transfection into osteosarcoma cells and these results suggest that magnetic cationic liposomes we developed can be a useful nonviral vector for targeted gene therapy.