Fig. 12

Schematic image showing the toxicity mechanisms of CoO and La₂O₃ nanoparticles. The redox potential of CoO nanoparticles falls into the biological redox potential (BRP), which allows electrons to transfer from biological molecules to CoO nanoparticles. This process could induce oxidative stress, leading to mitochondria damage, cell death and acute lung toxicity. In contrast, no electrons were transferred from biological system to La₂O₃ nanoparticles. However, La₂O₃ nanoparticles could transform into sea urchin LaPO4 in lysosomes, induce lysosomal damage, cathepsin B release, NLRP3 inflammasome activation and IL-1β production, which finally results in chronic lung inflammation and fibrosis