Perturbation of Nanoplastics on Biomembranes: Molecular Insights from Neutron Scattering

Plastic waste is now pervasive in the environment, breaking down into microplastics and nanoplastics under many environmental conditions. These particles have been found in various ecosystems and even in human tissues, raising significant environmental and health concerns. In this study, we investigated the interaction of polystyrene nanoplastics, with and without surface modifications, on biomembrane structures using contrast-matching small-angle neutron scattering and neutron spin echo spectroscopy. The neutron contrast matching enabled selective study of biomembranes in the presence of nanoplastics. Two model membranes were employed: a simple zwitterionic bilayer (i.e., dimyristoylphosphatidylcholine [DMPC]) and an Escherichia coli lipid extract as a bacterial membrane model. The results show profound membrane disruptions, including thinning, vesicle fragmentation, lipid monolayer formation, and inter-vesicle aggregation, with the most severe effects observed in DMPC membranes. Notably, E. coli membranes exhibited greater resilience, suggesting that biological membranes with diverse lipid compositions may mitigate some nanoplastic particle–induced damage. These findings highlight the potential risks posed by environmental nanoplastic particles to biological membranes, with insights for molecular-level interactions and the environmental toxicity of nanoplastics. This work provides a foundation for future studies into nanoplastic–biomembrane interactions and their broader implications for health and environment.