Isolation and characterization of nanoplastics from the environment and their reproductive toxicity

The widespread occurrence of microplastics (MPs) and nanoplastics (NPs) in natural environments, along with their associated potential health risks, has garnered significant scientific interest. Compared to MPs, NPs have a smaller particle diameter and a substantially larger surface-to-volume ratio. Therefore, NPs are hypothesized to pose a greater risk than MPs. In this study, we employed a multimodality approach combining pre-processing, transmission electron microscopy, and energy-dispersive X-ray spectroscopy to characterize NPs in natural water environments across China. Subsequently, we utilized commercially available fluorescent polystyrene NPs and MPs to conduct our biological comparisons. Flow cytometric analysis of RAW 264.7 cells revealed that NPs possess a markedly enhanced capacity to invade cells and provoke inflammatory responses compared to their MPs counterparts. Fluorescence imaging further demonstrated that NPs not only exhibit greater adhesion to food surfaces but also accumulate more readily than MPs in both adult zebrafish and their embryos. Finally, using uterine horn injection combined with Chicago blue staining, we confirmed that NPs induce more severe reproductive toxicity than MPs. The enhanced biological toxicity of NPs is likely attributable to their superior invasion and adhesion capability. Collectively, these findings provide a solid foundation for further investigations into the detrimental effects of NPs on human health.