A novel 3D intestine barrier model to study the immune response upon exposure to microplastics.

The plausibility of human exposure to microplastics has increased within the last years. Microplastics have been found in different food types including seafood, salt, sugar and beverages. So far, human health effects of microplastics after ingestion are unknown. Herein, we designed a novel, three-dimensional in vitro intestinal model consisting of the human intestinal epithelial cell lines Caco-2 and HT29-MTX-E12 as well as human blood monocyte-derived macrophages and dendritic cells that is suitable to assess the possible effects of ingested microplastics. Relevant microplastic particles (in the order of 50-500 µm), including polymers representing tire wear and polyolefins, which represent major sources of microplastic in the EU, were compared to other polymer classes and an inorganic microparticle, healing earth, which is intended for human consumption. Microplastic particles were exposed at concentrations of 823.5-1380.0 µg/cm