The humble zebrafish can be used to test the safety of transition metal oxide nanoparticles according to an international team.

Researchers in Germany and the US have used high-content bright-field and fluorescence-based imaging to compare the toxicological effects of copper, zinc, nickel and cobalt oxide nanoparticles on zebrafish embryos and larva. With the exception of the cobalt oxide, they observed a dose-dependent effect on hatching associated with interference with the hatching enzyme, ZHE1. The team suggests that the assay could be used as to rank the potential harmful effects of such nanoparticles on the aquatic environment.

• High Content Screening in Zebrafish Speeds up Hazard Ranking of Transition Metal Oxide Nanoparticles
  S. Lin, Y. Zhao, T. Xia, H. Meng, Z. Ji, R. Liu, S. George, S. Xiong, X. Wang, H. Zhang, S. Pokhrel, L. Maedler, R. Damoiseaux, S. Lin, A. E. Nel,
  ACS Nano 2011.
  DOI: 10.1021/nn202116p