Toxicity of Environmentally Relevant Micro- and Nanoplastic Exposure on Liver Cell Models

Rising plastic production worldwide is contributing to the increasing amounts of micro- and nanoplastics found in the environment. The consumption of microplastics by humans is plausible due to the presence of plastic particles in various food commodities, yet the potential impact of microplastics on human health remains unknown. Several studies have detected microplastics in human tissues and research using mammalian in vivo and in vitro models have noted toxicity after exposure to microplastics. Using both mono- and co-culture liver cell models, we assessed the impact of environmentally relevant, cryo-milled plastic particles on hepatotoxicity. We observed that only cryo-milled polyethylene terephthalate and polystyrene altered mitochondrial energy metabolism, while the other plastic particles did not. The pristine, spherical polystyrene particles were taken up at all sizes and cryo-milled polystyrene was taken up by cells. Evidently, polymer type and shape play a critical role in hepatotoxicity. Further research is required to fully elucidate the effect the physiochemical properties of plastic particles may have on toxicity.