EFFECTS OF CARBOXYMETHLY DEXTRAN MAGNETIC NANOPARTICLES CARRIER SYSTEM ASSOCIATED WITH EXTERNAL MAGNETIC FIELDS ON KILLING TUMOR CELLS AND GENE TRANSFECTION

摘要

Objective: To investigate the preparation of the carboxymethly dextran iron oxide magnetic nanoparticles (CDMN) and the effects of CDMN carrier system associated with external magnetic fields on killing tumor cells and gene transfection in vitro. Methods: Epirubicin-CDMN (EPI-CDMN) and green fluorescent protein (GFP) plasmid-CDMN (GFP-CDMN) were prepared by the oxidation-reduction procedure and their characters were detected, respectively. The effects of EPI-CDMN associated with external pulsed electromagnetic fields (PEMFs) (10 mT) on killing human bladder cancer BIU-87 cells were studied by MTT assay and Annexin-V/PI double-labeled flow cytometry technique, respectively. And the transfection efficiency of GFP when CDMN were used as gene carrier associated with the external magnetic fields was evaluated under fluorescence microscope in vitro. Results: The diameter of EPI-CDMN and GFP-CDMN were about 8~10 nm and 5~9 nm, respectively, and saturation magnetization were 0.22 emu/g and 0.26 emu/g, respectively. EPI-CDMN associated with PEMFs could significantly inhibit the proliferation of BIU-87 cells and induce cells apoptosis, the growth inhibitory rate and apoptosis rate were (21.82(3.18)% and (16.79(3.37)%, respectively. The transfection efficiency of GFP-CDMN combined with PEMFs was significant higher than that of GFP-CDMN without PEMFs [(45.70(4.32)% vs (35.85(2.16)%, P<0.05]. Conclusion: It seemed that EPI-CDMN associated with external magnetic fields could significantly killed human bladder cancer BIU-87 cells and CDMN could effectively transfer GFP gene into tumors cells with the help of external magnetic fields which provided experimental basis for the magnetic targeting therapy of tumor.