A 72-HOUR STUDY WITH GRAPHENE OXIDE NANOPARTICLES AND EASTERN OYSTERS
Citation:
Khan, B., A. Adeleye, R. Smolowitz, S. Russo, R. Burgess, AND K. Ho. A 72-HOUR STUDY WITH GRAPHENE OXIDE NANOPARTICLES AND EASTERN OYSTERS. National Shellfisheries Association 110th Annual Meeting, Seattle, WA, March 18 - 23, 2018.
Impact/Purpose:
The overall goal of this work is to evaluate responses of marine organisms to environmental exposures to carbon-based nanoparticles such as graphene oxide (GO). Given the increasing usage of graphene family nanomaterials in the field of electronics, material coatings, and biomedicine, it is likely that GO nanoparticles will make their way into aquatic ecosystems. Our knowledge of the environmental effects of such nanoparticles is very limited and incomplete. This research aims at understanding the impacts and toxicity of GO exposures using Eastern oysters as a model organism.
Description:
Graphene family nanomaterials (GFNs) are widely used in the field of electronics and biomedicine. Gaps in our knowledge about fate and toxicity of GFNs, such as graphene oxide (GO), raise concerns regarding their environmental impacts. Filter feeding bivalves, such as Crassostrea virginica (Eastern oysters), are good models to study the effects of GO exposures. The goal of this pilot study is to evaluate effects of in vivo GO exposures on oysters using a static renewal design. Oysters were exposed to 1 and 10 mg/L GO and fed a mixed algal diet. Each oyster was placed in a beaker with 1 liter of 0.22 µm filtered natural seawater and three renewals were performed daily. For every renewal, a GO suspension was prepared and sonicated before addition to beakers. Water samples were analyzed for GO concentration and effective diameter. At the end of 72 hours, oysters were placed in clean seawater for 3 hours and gill and digestive gland tissues were harvested. Tissues were analyzed for lipid peroxidation, a marker of oxidative damage, and for activity of glutathione-s-transferase (GST), a detoxification enzyme. Elevated lipid peroxidation in GO exposed oysters was found. No significant changes in GST activity were observed, but reduced total protein levels were noted in exposed oysters. Results indicate that short-term GO exposures can induce oxidative stress and adversely affect overall health in oysters. Evaluation of sublethal effects of exposures to an emerging contaminant, such as GO, is critical to understanding the risks associated with increasing commercial usage of nanoparticles.