Assessment of micro and nanoplastic toxicity and their protein corona using in vitro and in silico new approach methodologies

This thesis investigates whether micro and nanoplastics(MNPs) induce toxicity in the intestine, and whether the protein corona surrounding MNPs impacts toxicity. This thesis demonstrated that commonly used MNP models are not predictive of true microplastic toxicity to the intestine or resident immune cells. We show that this discrepancy is in part due to the overreliance on polystyrene materials and due to effects of a bound layer of proteins, called the protein corona, on toxicity and bioavailability. Finally we build one of the first in silico models that predict tissue concentrations after oral ingestion of MNPs. Overall our results show that specific proteins of the protein corona increase immunogenicity, generation of reactive oxygen species and barrier disruption as well as particle uptake through phagocytosis. Our in silico model predicts that at the moment MNP toxicity to humans is of low risk, however the differences between model MNPs and true-MNPs need to be considered as MNP risk assessment matures.