Copper oxide nanoparticles (CuONPs) have toxic properties that make them useful additives in commercial products that help prevent the growth of organisms in estuarine and marine environments. As the number of applications for these particles increases, so does their loading to the environment, where they can pollute aquatic ecosystems and induce undesired effects in non-target organisms. These can include oxidative stress damage that can lead to cell death, abnormal development and population declines.  We analyzed the effects of CuONP exposures during early developmental stages of the sea urchin, a well-known marine model organism. After 96 h of development and CuONP exposure, we did not detect significant oxidative damage to proteins or lipids. However, embryos exposed to 1 ppm CuONPs and greater developed abnormally and showed a decreased total antioxidant capacity. In embryos exposed to 50 ppb of copper sulfate as a source of copper ions, the effects were similar to 5 ppm of CuONP. Interestingly, the intracellular copper concentrations in the embryos exposed to 50 ppb copper sulfate and to 5 ppm CuONPs were 10 and 11 times higher than the concentration found in controls, respectively. Since these particular commercial CuONPs undergo very low dissolution (20 ppb soluble copper for 5 ppm CuONPs), the copper uptake by embryos must also be in the nanopaticulate form. Preliminary results with highly purified CuONPs showed that they have a higher toxicity as well as a higher dissolution rate. Studies are being conducted to determine the oxidative stress responses in sea urchins exposed to these particles. These results suggest that dissolution plays an important role in toxicity.  Although no effects were observed at concentrations of CuONPs that may be commonly observed in the environment with current use, CuONPs can induce abnormal development which may be linked to compromised antioxidant activity.

Oxidative stress responses in sea urchin embryos exposed to copper oxide nanoparticles

248th National Meeting (2014)

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