ToxSci Advance Access published online on December 10, 2008
Toxicological Sciences, doi:10.1093/toxsci/kfn256
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Comparison of molecular and histological changes in zebrafish gills exposed to metallic nanoparticles
Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611
Department of Zoology, University of Florida, Gainesville, FL 32611
Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611
Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611
griffitt{at}ufl.edukhyndman{at}zoology.ufl.edundenslow{at}ufl.eduBarberD{at}vetmed.ufl.edu
Received August 8, 2008; revision received October 31, 2008; accepted November 25, 2008
 |
Abstract |
|---|
Research has demonstrated that metallic nanoparticles produce toxicity in aquatic organisms that is due largely to effects of particulates as opposed to release of dissolved ions. The present research examined the interplay of nanoparticle composition and dissolution on response of the zebrafish gill following exposure to toxic (nanocopper or nanosilver) or non-toxic (nano-TiO2) nanometals. Female zebrafish were exposed to 48-hr NOEC concentrations of nanocopper and nanosilver or to soluble Cu and Ag that matched the concentration of dissolved metals released during nanoparticle exposure. Both nanocopper and nanosilver exposures increased metal content associated with gill tissue, though silver concentrations were much higher following nanosilver exposures suggesting that intact silver nanoparticles are associated with the gill. Morphological and transcriptional responses of the gills differed among various nanomaterials and between nanoparticulate and soluble species. Nanocopper increased mean gill filament width by three to four-fold between 24 and 48 hours, while nanosilver did not alter gill filament width at either time point. Global gene expression analysis demonstrates that the exposure to each nanometal or soluble metal produces a distinct gene expression profile at both 24 and 48 hours, suggesting that each exposure is producing biological response by a different mechanism. The differences in responses among the exposures indicates that each particle is having a distinct biological effect that does not appear to be driven solely by release of soluble metal ions into the water column. Based on these results, care should be taken when inferring toxicity of nanomaterials from data on a different material.