Bioeffects of Nanoplastics: DNA Damage and Mechanism

Nanoplastics, as emerging contaminants, have been causing great panic, potentially affecting human health in recent years. Some in vitro studies have indicated that nanoplastics may induce severe toxicity. However, the mechanisms underlying this potential toxicity are insufficiently understood. In this study, we have found PS-NH₂ nanoplastics had the obvious DNA cleavage activities, while PS-COOH nanoplastics were not observed to have the DNA cleavage abilities. Both microsized PS-NH₂ and PS-COOH microplastics lacked DNA cleavage activities, indicating the importance of size and surface ligand in nanoplastics' DNA cleavage. The DNA cleavage system by nanoplastics remains stable under varying pH and temperature. From the mechanism exploration, the interaction energy is much higher between PS-NH₂ nanoplastics than PS-COOH nanoplastics, further illuminating that PS-NH₂ nanoplastics have stronger binding interaction with DNA to induce DNA cleavage activities. This study offers insights into the potential environmental risks and toxicity of nanoplastics in the aquatic ecosystems.