Toxicological evaluation of biosynthesised hematite nanoparticles in vivo.

In recent years, nanomaterials have been widely used in consumer products. High reactivity of metallic nanoparticles and its bioaccumulation in biological systems are the main causes of concern over their safety to human health and environment. The available information related to the safety of several nanomaterials is insufficient. Hematite nanoparticles are proposed for various applications. Ecotoxicological studies of hematite nanoparticles are very limited. In the present study, biosynthesised hematite nanoparticles using Bacillus cereus were evaluated for its acute oral toxicity in mice following OECD guidelines. A dose of 2 g/kg/p.o was administered to Swiss albino mice through gastric oral feeding tube and observed for 14 days. After two weeks blood samples were collected and subjected for evaluation of haematological parameters and biochemical analysis. There was no mortality and toxic signs of animals till the end of observational period. The animals were sacrificed and organs like liver and kidneys were isolated to study the histopathological changes. The results of the study revealed that there was no drastic change in parameters except slight change in bilirubin in the hematite nanoparticle treated mice. Biosynthesised hematite nanoparticles were assayed for toxicity in Artemia salina. Cysts treated with higher concentrations of hematite nanoparticles showed small sized nauplii. Biosynthesised hematite nanoparticles were found to be non-toxic to A. salina nauplii in lower concentrations.