Genotoxicity of copper oxide and silver nanoparticles in the mussel Mytilus galloprovincialis

Though there is some information on cytotoxicity of copper nanoparticles and silver nanoparticles on human cell lines, there is no information on their genotoxic and cytotoxic behaviour in bivalve molluscs. The aim of this study was to investigate the genotoxic impact of copper oxide and silver nanoparticles using mussels Mytilus galloprovincialis. Mussels were exposed to 10 μg L−1 of CuO nanoparticles and Cu2+ and Ag nanoparticles and Ag+ for 15 days to assess genotoxic effects in hemocytes using the comet assay. The results obtained indicated that copper and silver forms (nanoparticles and ionic) induced DNA damage in hemolymph cells and a time-response effect was evident when compared to unexposed mussels. Ionic forms presented higher genotoxicity than nanoparticles, suggesting different mechanisms of action that may be mediated through oxidative stress. DNA strand breaks proved to be a useful biomarker of exposure to genotoxic effects of CuO and Ag nanoparticles in marine molluscs.

► CuO and Ag NPs are genotoxic towards mussels' hemocytes.
► Increasing DNA damage effects with time of exposure for both forms of Cu and Ag.
► CuO and Ag NPs possess DNA damaging potential mediated by oxidative stress.
► Different toxic mechanisms are involved in DNA damage, dependent on the metal form.
► The comet assay is a useful tool for monitoring NPs toxicity in the environment.