Detection of immune system activation in hemolymph of Drosophila larvae exposed to chitosan-coated magnetite nanoparticles

Drosophila melanogaster hemolymph cells are confirmed as a model to study the activation of immune system due to foreign stimuli like iron nanoparticles. The toxicity of nanoparticles is a cause for concern due to their effect on human health and the environment. The aim of this study was to detect the activation of cellular immune response in Drosophila larvae through the observation of hemolymph composition, DNA damage and larval viability, after the exposure to 500 ppm and 1000 ppm chitosan-coated magnetite nanoparticles for 24 hours. Our results showed activation of cellular immune response after exposure to the nanoparticles owing to the increment of hemocytes, the emergence of lamellocytes and the presence of apoptotic hemocytes. In addition, chitosan-coated magnetite nanoparticles produce DNA damage detected by comet assay as well as low viability of larvae. No DNA damage is showed at 500 ppm. The cellular toxicity is directly associated with 1000 ppm.