Projects per year
Nanodiamonds are a type of engineered nanomaterial with high surface area that is highly tunable and are being proposed for use as a material for medical imaging or drug delivery to composites. With their potential for widespread use they may potentially be released into the aquatic environment as are many chemicals used for these purposes. It is generally thought that nanodiamonds are innocuous, but toxicity may occur due to surface functionalization. This study investigated the potential oxidative stress and antioxidant response of enterocytes in a freshwater invertebrate, Daphnia magna, a common aquatic invertebrate for ecotoxicological studies, in response to two types of functionalized nanodiamonds (polyallylamine and oxidized). We also examined how the size of the nanomaterial may influence toxicity by testing two different sizes (5 nm and 15 nm) of nanodiamonds with the same functionalization. Adults of Daphnia magna were exposed to three concentrations of each of the nanodiamonds for 24 h. We found that both 5 and 15 nm polyallylamine nanodiamond and oxidized nanodiamond induced the production of reactive oxygen species in tissues. The smaller 5 nm nanodiamond induced a significant change in the expression of heat shock protein 70 and glutathione-S-transferase. This may suggest that daphnids mounted an antioxidant response to the oxidative effects of 5 nm nanodiamonds but not the comparative 15 nm nanodiamonds with either surface chemistry. Outcomes of this study reveal that functionalized nanodiamond may cause oxidative stress and may potentially initiate lipid peroxidation of enterocyte cell membranes in freshwater organisms, but the impact of the exposure depends on the particle size.
Bibliographical noteFunding Information:
We thank the Great Lake Genomics Center at School of Freshwater Sciences-UWM for the use of the equipment to monitor gene expression. J.T.B. acknowledges support by a National Science Foundation Graduate Research Fellowship (Grant number 00039202 ). TEM work in this study was carried out in the Characterization Facility, University of Minnesota, which receives partial support from National Science Foundation, United States through the MRSEC program.
This work was funded by the National Science Foundation under the Center for Sustainable Nanotechnology (CSN), CHE‐1503408. The CSN is part of the Centers for Chemical Innovation Program.
© 2018 Elsevier Inc.
- Gene expression
- Oxidative stress
- Reactive oxygen species
How much support was provided by MRSEC?
Reporting period for MRSEC
- Period 5
PubMed: MeSH publication types
- Journal Article
- Research Support, U.S. Gov't, Non-P.H.S.