Removal and toxic intervention of polystyrene microplastics and nanoplastics by magnetic nano-Fe3O4 in spermatogonial GC-1 cells

Microplastics and nanoplastics (MNPs) are widespread in the environment and have male reproductive toxicity. However, toxic interventions involving MNPs have not been extensively examined. In this investigation, we explored the elimination capacity of magnetic nano-Fe₃O₄ on polystyrene microplastics and nanoplastics (PS-MNPs) of different sizes. This study also investigated whether magnetic nano-Fe₃O₄ could alleviate the toxicity of PS-MNPs in spermatogonial GC-1 cells. After coprecipitation by magnetic nano-Fe₃O₄ in ddH₂O, the removal rates of polystyrene microplastics (PS-MPs, 4 and 10 μm) are much higher than those of PS-NPs (25 nm, 100 nm, and 500 nm). The removal rate of the PS-NPs dramatically enhanced in the salt ion solutions. In addition, 25-nm, 100-nm, 500-nm, and 4-µm PS-MNPs penetrated GC-1 cells. Nevertheless, exclusively 25-nm PS-NPs decreased cell viability, elevated reactive oxygen species, disrupted the mitochondrial membrane potential, and induced apoptosis and inflammation through the P38/MAPK and Nrf2/HO-1 signaling pathways in GC-1 cells. Interestingly, magnetic nano-Fe₃O₄ alleviated these harmful impacts of the 25-nm PS-NPs on the GC-1 cells. In conclusion, we demonstrated the toxicity of PS-NPs in GC-1 cells and provided a viable way to alleviate their toxicity.