Doxorubicin-loaded dendritic-Fe3O4 supramolecular nanoparticles for magnetic drug targeting and tumor regression in spheroid murine melanoma model.

This work evaluates the magnetically-guided delivery of DOX-loaded dendritic-Fe3O4 nanoparticles and their tumor regression efficacy in subcutaneous melanoma in C57BL/6 mice. The hematological, biochemical and histopathological parameters were minimally affected. The nanoparticles localized in lungs, liver and spleen suggesting non-specific uptake. However, in tumor-bearing mice, substantially higher localization in magnetically-targeted tumor was observed when compared to passive localization in non-targeted tumor. The animals of treated group showed significantly high iron levels (161 μg of Fe/mg dry organ weight) in the tumor against the control (<25 μg of Fe/mg dry organ weight). This high localization led to high concentrations of DOX in the tumor which not only induced significant tumor regression but also arrested further growth. Within 14 days, the average tumor volume was reduced to 55±8.3 mm3 (treated) as compared to 4794±844 mm3 (control), i.e. ~88-fold decrease. The tumor disappeared by the end of 20th day post-treatment and ~100% survival rate was observed.