Toxicity and biodistribution assessment of curcumin-coated iron oxide nanoparticles: Multidose administration

Iron oxide nanoparticles (IONPs) have been widely used in diagnosis, drug delivery, and therapy. However, the biodistribution and toxicity profile of IONPs remain debatable and incomplete, thus limiting their further use. We predict that coating iron oxide nanoparticles using curcumin (Cur-IONPs) will provide an advantage for their safety profile. In this study, an evaluation of the multidose effect (6 doses of 5 mg/kg Cur-IONPs to male BALB/c mice, on alternating days for two weeks) on the toxicity and biodistribution of Cur-IONPs was conducted. Serum biochemical analysis demonstrated no significant difference in enzyme levels in the liver and kidney between the Cur-IONP-treated and control groups. Blood glucose level measurements showed a nonsignificant change between groups. However, the serum iron concentration was found to initially increase significantly but then decreased at 10 days after the final injection. Histopathological examination of the liver, spleen, kidneys, and brain showed no abnormalities or differences between the Cur-IONP-treated and control groups. There were no abnormal changes in mouse body weight. The biodistribution results showed that Cur-IONPs accumulated mainly in the liver, spleen, and brain, while almost no Cur-IONPs were found in the kidney. The iron content in the liver remained high even 10 days after the final injection, while the iron content in the spleen and brain had returned to normal levels by this time point, indicating their complete clearance. These results are significant and promising for the further application of Cur-IONPs as theragnostic nanoparticles.