Nanoplastic-Induced Biological Effects In Vivo and In Vitro: An Overview

Nanoplastics (NPs) are emerging pollutants with great concern due to their small size and potential adverse effects on living organisms. This review summarizes the biological effects of NPs in vivo (plants and animals) and in vitro (cells). NPs can be ingested and accumulated in organisms and transferred along the food chain, affecting the growth, development, and reproduction at each trophic level. Several factors including surface charges, size, exposure dose, and exposure time affect the biological effects of NPs. Surface-charged NPs have a more significant impact on the normal physiological activities of cells, while smaller particles facilitate the penetration across the cell membranes. Higher doses and longer exposure time contribute to the higher accumulation. In addition, additives and environmental pollutants attached to NPs pose a greater threat to organisms than NPs themselves. There are still several analytical challenges in the study of the biological effects of NPs, especially their accumulation, degradation, migration and interactions with the biological systems. Further works on the risk assessment of NPs derived from commonly used plastics in our daily life like polyethylene terephthalate (PET) rather than laboratory-made polystyrene (PS) beads are still highly desired.