Effects of micro(nano)plastics on amphibian cell lines

Plastic materials, when released into the environment are submitted to abiotic and biotic processes that promote their fragmentation into microplastics (100 nm ¡ MP ¡ 5 mm) and nanoplastics (NP ¡ 100 nm). The increased concern regarding the presence of plastic particles in the environment led to the search for alternative materials like bioplastics. Whether bio-based plastics are more environmentally friendly than conventional fuel-based plastics is yet to be proven. There is thus the need to study the impact of small plastic particles, in organisms that are under anthropogenic pressure, like amphibians. However, ethical constraints limit the tests that can be used to understand the dangers of MP and NP in these organisms. Therefore in vitro cellular models based on established cell lines are of great importance for the risk assessment of MP and NP. This study aimed to evaluate the effects of micro(nano)plastics of two fuel-based polymers (polymethylmethacrylate (PMMA) and polystyrene (PS)) and one biobased polymer (polylactic acid (PLA)) on two amphibian cell lines A6 (adult Xenopus laevis kidney epithelial cell line) and XTC-2 (tadpole Xenopus laevis carcass fibroblast cell line). The selected cell lines were exposed to NP (from 0 to 400 mg/L) and MP (from 0 to 200 mg/L) obtained by laboratory synthesis (PMMA) or fragmentation of larger particles (environmentally relevant shapes – PS and PLA), and cell viability and reactive oxygen species (ROS) production were respectively evaluated using MTT assay (at 72 hours) and DCFDA assay (at 3 hours). Overall, no significant effects on the viability of A6 cells were observed after exposure to PMMA NP, despite the increase in ROS production, while cell viability decreased after exposure to PLA MP. The viability of XTC-2 decreased at the highest concentration of PLA MP and PMMA NP, while PS MP induced no significant effects on cell viability. Also see: https://micro2024.sciencesconf.org/559745/document