Uptake Route Altered the Bioavailability of Graphene in Misgurnus anguillicaudatus: Comparing Waterborne and Sediment Exposures

Abstract

Numerous studies on the bioavailability of graphene-based nanomaterials relate to the water-only exposure route. However, the sediment exposure route should be the most important pathway for benthic organisms to ingest graphene, while to date little work on the bioavailability of graphene in benthic organisms has been explored. In this study, with the help of carbon-14-labeled few-layer graphene (14C-FLG), we quantificationally compared the bioaccumulation, biodistribution, and elimination kinetics of 14C-FLG in loaches via waterborne and sediment exposures. After 72 h of exposure, the accumulated 14C-FLG in loaches exposed via waterborne was 14.28 μg/g (dry mass), which was 3.18 times higher than that (4.49 μg/g) exposed via sediment. The biodistribution results showed that, compared to waterborne exposure, sediment exposure remarkably facilitated the transport of 14C-FLG from the gut into the liver, which made it difficult to be excreted. Although 14C-FLG did not cause significant hepatotoxicity, the disruption of intestinal microbiota homeostasis, immune response, and several key metabolic pathways in the gut were observed, which may be due to the majority of 14C-FLG being accumulated in the gut. Overall, this study reveals the different bioavailabilities of graphene in loaches via waterborne and sediment exposures, which is helpful in predicting its bioaccumulation capability and trophic transfer ability.

Exposure of Midge Larvae (Chironomus riparius) to Graphene Oxide Leads to Development Alterations

“…GBM accumulation in the digestive tract of multiple aquatic organisms living in different ecological niches, including vertebrates [ 45 , 59 , 60 ], pelagic invertebrates [ 24 , 61 , 62 ] and benthic invertebrates such as C. riparius [ 27 ], was previously observed. GO accumulation within the digestive tract of this species could favor the trophic transfer of GO towards secondary consumers feeding on this species.…”

Molecular Imaging, Radiochemistry, and Environmental Pollutants

“…However, their attractive physicochemical properties and high biocompatibility have fueled a rise in their use across several industries. Graphene nanomaterials are 2-dimensional lattices of carbon atoms that, once released into the environment, are prone to aggregation and settlement into sediment layers ( 33 , 34 ). It is estimated that the world’s production of graphene will reach 3,800 tons by 2027, so gaining an improved understanding of the pollutant’s in vivo behavior is of paramount importance.…”

“…Although the 14 C-labeled few-layer graphene was increasingly excreted via the feces, almost 50% of the dose remained in the lungs after 4 wk. Lu et al also synthesized 14 Clabeled few-layer graphene but added their construct to water and sediment and subsequently quantified its bioaccumulation and biodistribution in loaches (M. anguillicaudatus), a type of freshwater, bottom-dwelling fish that ingests large amounts of sediment and are consumed by humans and other water-dwelling animals (33). After only 72 h in a container with sediment mixed with 14 Clabeled few-layer graphene, radioactivity was found in the gut and liver of the loaches.…”