Genotoxic effects of Ag2S and CdS nanoparticles in blue mussel (Mytilus edulis) haemocytes.

The use of functionalised metal sulphide nanoparticles (NPs) for nanoremediation and biomedical application is rapidly increasing, which could lead to significant inputs into the marine environment. The potential impact of some NPs on marine organisms is still poorly understood. In the present paper the genotoxic potential of Ag2S and CdS NPs on Mytilus edulis haemocytes was assessed. MPEG-SH (thiol-terminated methyl polyethylene glycol), was used as capping agent to avoid NPs agglomeration. TEM analysis showed that the Ag2S NPs size was 13±7 nm, whereas CdS quantum dots had an average diameter of 4±1 nm. DNA integrity was evaluated by Comet assay following exposure to increasing concentration series (0.01–10 mg/L). Both silver and cadmium NPs showed genotoxic effects at the highest dose. MPEG-SH was also found to exert a weak genotoxic activity, suggesting that at least part of the genotoxic potential of functionalised NPs on mussel cells might be attributable to the capping agent. These results confirm the genotoxic potential of Ag2S NPs for mussel cells and demonstrated, for the first time, that CdS NPs is genotoxic in a marine organism.