In vitro bioassays as a tool to evaluate risk assessment of micro and nanoplastics

The concern regarding nano and microplastics has significantly increased as they can be present in food, water and environment. Once the particles enter the food chain, they can cross the biological barriers, as well as cell membranes, leading to different molecular effects. In this sense, some key challenges must be overcome to carry out a risk assessment of micro and nanoplastics. On one hand, the availability of standards of micro and nanoplastics that allow robust and reproducible results to be obtained; and on the other hand, a standardised battery of tests to assess the risk at the different trophic levels of the food chain. Non-animal approaches as in vitro bioassays based in cell culture assays have been used for the evaluation of complex mixtures of chemicals present at a very low level. For particles, specifically, some properties must be considered to design a suitable battery of bioassays, such as characterization, impurities, surfaces, dissolution ratio or stability under biological conditions. The aim of the study is to develop standards of micro and nanoplastics (PLA, PET and PE) to be used, first of all, in an in vitro gastrointestinal digestion to evaluate their stability and dissolution under biological conditions and, finally, to assess cytotoxicity (Alamar Blue), oxidative stress (ROS) and genotoxicity (Micronucleus and Comet assay) in different cell lines. The study demonstrates the importance of standardization in the manufacturing of micro and nanoplastics and the necessity of developing a standardized in vitro gastrointestinal digestion and a battery of in vitro bioassays for the evaluation of hazards related to these particles and guarantee consumer safety. Also see: https://micro2024.sciencesconf.org/564408/document