abstract
Nanographene oxide (nGO) has been recently proposed as a new antitumoral therapeutic agent, drug delivery carrier and gene transfection vehicle, among others. Treatment is carried out by hyperthermia induced by infrared irradiation. After treatment, the nanosystems will be inevitably excreted and released to the environment. To understand the potential impacts of pegylated nGO (nGO-PEG), three key species from different trophic levels were used: the green micro-algae Raphidocelis subcapitata (growth inhibition test), the cladocera Daphnia magna (acute and chronic tests), and the fish Danio rerio (fish embryo test). Besides a regular standard procedure to assess toxicity, and considering the mode of action of nGO-PEG in cancer treatment, a simultaneous infrared lamp exposure was carried out for D. magna and D. rerio. Additionally, and taking advantage of the phenotypic transparency of D. magna, nGO-PEG was fluorescently tagged to evaluate the potential uptake of nGO-PEG. The R. subcapitata growth inhibition test showed effects during the first 48 h, recovering till the end of the test (96 h). No acute or chronic effects were observed for D. magna, under standard or infrared light exposures although confocal microscope images showed nGO-PEG uptake. Very small percentages of mortality and abnormalities were observed in D. rerio exposed with and without the infrared lamp. Although low hazard may be expected for nGO-PEG in aquatic ecosystems, further studies with species with different life traits should be accomplished, in order to derive more accurate conclusions.
keywords
IN-VITRO; WATER; TOXICITY; NANOMATERIALS; INHIBITION; NANOSHEETS
subject category
Environmental Sciences & Ecology; Toxicology
authors
Loureiro, S; Goncalves, SF; Goncalves, G; Hortiguela, MJ; Rebelo, S; Ferro, MC; Vila, M
our authors
Marta Ascenção Carmona Ferro
Laboratory OfficerGroups
acknowledgements
The authors declare no competing financial interest. This work was supported by CESAM (UID/AMB/50017) from FCT/MEC through national funds, and the cofunding by FEDER (POCI-01-0145-FEDER-007638), within the PT2020 Partnership Agreement and Compete 2020, and by the Institute for Biomedicine (UID/BIM/04501/2013 and POCI-01-0145-FEDER-007628).