Cellular uptake, Transport, and Inflammatory Responses of Polyethylene Terephthalate (PET) and Polyvinyl Chloride (PVC) Nanoplastics in In Vitro Caco-2 Monoculture/Mucus Model.

Human exposure to nanoplastics (NPls) has raised increasing concern due to their potential health impacts. Our recent work suggested that the polymer type may influence NPl uptake and inflammatory responses in differentiated Caco-2-based intestinal models. In this study, iDye-pink-labeled polyethylene terephthalate (PET, 120nm) and polyvinyl chloride (PVC, 94nm) NPls were evaluated using differentiated Caco-2 and Caco-2/HT29-MTX mucus models at a concentration exceeding estimated real-life levels. Neither PET nor PVC NPls induced acute loss of cell viability or disruption of barrier integrity. Both particles showed similar cellular uptake patterns and interaction levels. However, PET NPls exhibited a significantly higher transport rate than PVC NPls in the mucus model, whereas transport of both particles remained lower than in the monoculture model. In addition, PVC NPls induced IL-1β release, whereas PET NPls increased TNF-α secretion. These findings indicate that polymer composition may influence intestinal transport of NPl and their inflammatory response.