TiO2 nanoparticles combined with polystyrene nanoplastics aggravated reproductive toxicity in female mice via exacerbating intestinal barrier disruption

TiO2 nanoparticles (NPs), a widely used food additive in the food industry, have been shown to aggravate the progress of metabolic diseases. Nanoplastics (NPLs) are an emerging contaminant widely present in the food system and have been shown to induce ovarian disorders in mammals. Noteworthy, they can be ingested by humans through 'contaminated' food, whereas the potential toxicity of NPLs and TiO2 NPs combined remains unclear. In the present study, we investigated the potential effects and mechanisms of co-exposure to polystyrene (PS) NPLs and TiO2 NPs on the ovary in female mice.Our results revealed that the co-exposure of TiO2 NPs and PS NPLs caused significant injury to ovarian structure and function, but individual exposure had no effect. Moreover, compared to the TiO2 NPs group, co-exposure aggravated the intestinal barrier damage in mice, increasing the bioaccumulation of TiO2 NPs in the ovary. After being supplemented with the oxidative stress inhibitor N-acetyl-l-cysteine, the expression of ovarian antioxidant genes increased, and the ovarian structural and functional injury in co-exposure mice reverted to normal levels.The present study demonstrated that co-exposure to PS NPLs and TiO2 NPs can cause more severe female reproductive dysfunction and deepens the toxicological insights between NPLs and NPs. © 2023 Society of Chemical Industry.