Oil-Encapsulated Nanoplastics from Plastic Disposable Food Containers Induce Rapid Cell Death through Cell Membrane Disruption

<title>Abstract</title> The rise of food delivery culture has resulted in millions of tons of food-contact plastic containers being used each year, yet the risks of micro(nano)plastics (MNPs) released during the storage of oil-rich foods are still not well understood. Here, we investigated MNP release from polypropylene (PP) and polyethylene (PE)-coated containers under simulated takeout scenarios. When exposed to cooking oil and microwave heating, containers released up to 125-fold more MNPs and 471-fold more heavy metals compared to water exposure, with significantly altered physicochemical properties. Oil-derived PP NPs, uniquely encapsulated in oil films with positive surface charge (+7.37 mV). The positive charge of oil-derived NPs may enhance their interaction with negatively charged cell membranes, leading to rapid cell death within 5 minutes at a concentration of 100 μg/mL through membrane disruption. Transcriptomic analysis revealed that oil-PP NPs triggered substantially more extensive gene expression changes than water-derived NPs, particularly in pathways related to acute cellular stress and mitochondrial energy metabolism. Global exposure assessments highlight annual human intake of up to 3.35 g from oil-rich takeout food. Based on integrated cellular and molecular endpoints, we established a benchmark dose lower limit (BMDL) of 1.18 μg/mL for oil-PP NPs. MNP abundance in human biological samples exceeds BMDL thresholds, suggesting significant health risks. Our findings reveal previously unknown mechanisms of oil-derived MNP toxicity and underscore the urgent need for stricter regulation of plastic food packaging used with oil-rich foods.