Animal experiment on anti-tumor activity of magnetic nanocarrier and doxorubicin with target simple external magnetic fields

Objective For the effective chemotherapy of solid tumors, to develop a magnetic nanoparticles conjugated with drug release delivery compound, which can enhance the anti-tumor activity with external magnetic fields. Methods Fe3O4 and DOX were incorporated into poly-lactic acid/glycolic acid (PLGA) by a self-assembly procedure to form a micelle-encapsulated Fe3O4 and Dox complex (Fe3O4-PLGA-DOX). BALB/C mice bearing LLC tumors were treated by Fe3O4-PLGA-DOX with or without external magnetic fields. The lesions of main organs and iron deposition were examined by pathological special staining. Results Mice treated by Fe3O4-PLGA-DOX with external magnetic field group displayed significant reduction in tumor volume (1.027 cm3 ± 0.606 cm3) compared with free doxorubicin group (1.698 cm3 ± 0.971 cm3) or Fe3O4-PLGA-DOX without external magnetic fields group (1.911 cm3 ± 1.003 cm3). The metastases incidence of Fe3O4-PLGA-DOX with external magnetic field was also lower than free doxorubicin group or Fe3O4-PLGA-DOX without external magnetic fields group. There was no detectable lesion in heart, lung, liver and kidney in mice treated by Fe3O4-PLGA-DOX with external magnetic field. In contrast, the iron oxide deposited in tubules of kidney in a few mice which was not applied external magnetic fields. Conclusions The Fe3O4 -PLGA -DOX is a new designed drug, which can be concentrated in tumor with external magnetic fields. This physical targeted delivery modality may provide a new strategy for the design of cancer therapies. Key words: Neoplasms; Magnetic nanoparticles; External magnetic fields; Poly-lactic acid/glycolic acid; Doxorubicin