Graphene Oxides (GOs) with Different Lateral Dimensions and Thicknesses Affect the Molecular Response in Chironomus riparius

Abstract

Graphene oxide (GO) materials possess physicochemical properties that facilitate their application in the industrial and medical sectors. The use of graphene may pose a threat to biota, especially aquatic life. In addition, the properties of nanomaterials can differentially affect cell and molecular responses. Therefore, it is essential to study and define the possible genotoxicity of GO materials to aquatic organisms and their ecosystems. In this study, we investigated the changes in the expression of 11 genes in the aquatic organism Chironomus riparius after 96 h of exposure to small GOs (sGO), large GOs (lGO) and monolayer GOs (mlGO) at 50, 500 and 3000 μg/L. Results showed that the different genes encoding heat shock proteins (hsp90, hsp70 and hsp27) were overexpressed after exposure to these nanomaterials. In addition, ATM and NLK—the genes involved in DNA repair mechanisms—were altered at the transcriptional level. DECAY, an apoptotic caspase, was only activated by larger size GO materials, mlGO and lGO. Finally, the gene encoding manganese superoxide dismutase (MnSOD) showed higher expression in the mlG O-treated larvae. The lGO and mlGO treatments indicated high mRNA levels of a developmental gene (FKBP39) and an endocrine pathway-related gene (DRONC). These two genes were only activated by the larger GO materials. The results indicate that larger and thicker GO nanomaterials alter the transcription of genes involved in cellular stress, oxidative stress, DNA damage, apoptosis, endocrine and development in C. riparius. This shows that various cellular processes are modified and affected, providing some of the first evidence for the action mechanisms of GOs in invertebrates. In short, the alterations produced by graphene materials should be further studied to evaluate their effect on the biota to show a more realistic scenario of what is happening at the molecular level.

Synthesis and Characterization of Maghemite Nanoparticles Functionalized with Poly(Sodium 4-Styrene Sulfonate) Saloplastic and Its Acute Ecotoxicological Impact on the Cladoceran Daphnia magna

“…On the other hand, the morphological parameters (heart, tail, body, and antenna) showed a significant change with respect to the concentrations, except for the 800 mg L −1 concentration, in which the antenna and heart parameters did not present a substantial modification. It is important to mention that these changes in morphological parameters may be related to genotoxicological damage occurring in D. magna , as also observed in Chironomus riparius using graphene oxide, in which there was an alteration in genes involved in the metabolism [ 64 ]. Thus, it can be inferred that it probably occurred after D. magna ingested γ-Fe 2 O 3 @PSSNa, which has an intermediate size between 20 nm and 70 μm, as suggested by Matson [ 62 ].…”