Cytotoxicity of Fe3O4/Au composite nanoparticles loaded with doxorubicin combined with magnetic field.

GoldMag (Fe3O4/Au) nanoparticles have the advantages of both magnetic response in an external magnetic field and the immobilization of molecules on their surface in a single step. The cytotoxicities of GoldMag nanoparticles and GoldMag nanoparticles loaded with doxorubicin (Dox-GoldMag) combined with an external magnetic field were tested in vitro on HepG2 malignant tumor cells. The results showed that cell viability remained above 92% when using GoldMag nanoparticles at a concentration as high as 2.0 mg/ml, suggesting the biocompatibility of the nanoparticles. The IC50 (0.731 microg/ml) of the Dox-GoldMag group was higher than that (0.522 microg/ml) of the Dox group (P < 0. 05). However, the Dox-GoldMag group combined with a magnetic field had an obviously increased inhibition rate for the HepG2 cell line and the IC50 was lower than that of the Dox group (0.421 microg/ml). These results indicated that GoldMag nanoparticles loaded with doxorubicin combined with a permanent magnetic field are more cytotoxic and could be a potential targeted drug delivery system.