Cerium oxide nanoparticles induce oxidative stress in the sediment-dwelling amphipodCorophium volutator

Abstract

Cerium oxide nanoparticles (CeO2 NPs) exhibit fast valence exchange between Ce(IV) and Ce(III) associated with oxygen storage and both pro and antioxidant activities have been reported in laboratory models. The reactivity of CeO2 NPs once they are released into the aquatic environment is virtually unknown, but this is important to determine for assessing their environmental risk. Here, we show that amphipods (Corophium volutator) grown in marine sediments containing CeO2 NPs showed a significant increase in oxidative damage compared to those grown in sediments without NPs and those containing large-sized (bulk) CeO2 particles. There was no exposure effect on survival, but significant increases in single-strand DNA breaks, lipid peroxidation and superoxide dismutase activity were observed after a 10-day exposure to 12.5 mg L(-1) CeO2. Characterisation of the CeO2 NPs dispersed in deionised or saline exposure waters revealed that more radicals were produced by CeO2 NPs compared with bulk CeO2. Electron energy loss spectroscopy (EELS) analysis revealed that both CeO2 NPs were predominantly Ce(III) in saline waters compared to deionised waters where they were predominantly Ce(IV). In both types of medium, the bulk CeO2 consisted mainly of Ce(IV). These results support a model whereby redox cycling of CeO2 NPs between Ce(III) and Ce(IV) is enhanced in saline waters, leading to sublethal oxidative damage to tissues in our test organism.

Potential Hazard of Lanthanides and Lanthanide-Based Nanoparticles to Aquatic Ecosystems: Data Gaps, Challenges and Future Research Needs Derived from Bibliometric Analysis

“…No adverse effects of CeO 2 NPs on chironomid development, growth, or emergence were reported upon exposure up to 100 mg/L, despite the fact that ingestion of the particles by organisms was recorded [72]. 10-day CeO 2 NPs exposure to up to 100 mg/L did not induce mortality for sediment-dwelling amphipod Corophium volutator, while DNA damage and oxidative stress were induced at exposure concentration of 12.5 mg/L [73]. CeO 2 NPs induced significant adverse biological effects in long-term studies with crustaceans and fish at 10-100 mg Ce/L [74,75].…”

<p>Antioxidant and toxicity studies of biosynthesized cerium oxide nanoparticles in rats</p>

“…[33][34][35] Antioxidants could be harmful per se, because of pro-oxidant activity. [36][37][38] For example, Srinivas et al suggested that acute exposure of CNPs through inhalation route may induce cytotoxicity via oxidative stress and may lead to a chronic inflammatory response. 39 Adebayo et al also showed that administration of 100-300 mg/kg CNPs thrice in a week for 5 consecutive weeks to mice induces testicular dysfunction via disruption of antioxidant/oxidant balance and endocrine suppression.…”

Bioaccumulation and toxic effects of nanoparticulate and ionic silver in Saccostrea glomerata (rock oyster)

“…Samples of ASW (5mL) were taken consecutively from each of the tanks and added into Amicon 15 centrifugal filter units (Millipore®; with regenerated cellulose acetate membranes with 3kDa cut off value and PP filter housing). The units were centrifuged for 30 min at 4444 g-force (Eppendorf 5804-R) (Dogra et al 2016). The supernatants were acidified to a final concentration of 2% (w/v) HNO 3…”

“…Details about the tissue extraction are shown in SI †. The samples were then acid-digested with 4mL of (1:4) H 2 O 2 and HNO 3 (w/v) for 2h at 60°C using a microwave (CEM Mars-5 Microwave accelerated reaction system) (Dogra et al 2016) . The solutions were filtered with a syringe filter with 0.2μm Supor® membrane and the total Ag concentration was measured by ICP-OES.…”