Evaluation of pulmonary toxicity of zinc-doped magnetite nanoparticle in mice after intragastric administration

Zn2+ doped magnetite nanoparticles (ZnaFebO4 NPs) have higher magnetic susceptibility than conventional magnetite nanoparticles (Fe3O4 NPs). Dimercaptosuccinic acid (DMSA)-coated Zn0.4Fe2.6O4 nanoparticles (Zn0.4Fe2.6O4 NPs) were synthesized. The pulmonary toxicity of DMSA-coated Zn0.4Fe2.6O4 NPs in mice was evaluated after oral administration for one month. No abnormal activities among the mice were observed in Zn0.4Fe2.6O4 NPs-treated group during the whole experiment process. The accumulation of Fe in the lungs was observed after oral administration of DMSA-coated Zn0.4Fe2.6O4 NPs in mice. The accumulation of Fe in the lungs resulted in an increase of coefficient of lung, but did not cause obvious pulmonary injury, except for a very slight inflammatory response in the tissue. The results show that low toxic DMSA-coated Zn0.4Fe2.6O4 NPs may be used as drug delivery or imaging contrast agents by oral route.