CeO₂ nanoparticles attenuate airway mucus secretion induced by TiO₂ nanoparticles

Nanotoxicity studies associated with various nanoparticles (NPs) have attracted intense research interest due to the broader applications of nanoparticles in our daily lives. The exposure of nanoparticles can lead to hypersecretion and accumulation of airway mucus which are closely associated with many respiratory diseases. Titanium dioxide (TiO₂), one of the PM10 components, is a major NP that is widely utilized in many commercial products. Our previous study established the connection between induced airway mucus secretion and TiO₂ NPs. However, the countermeasure to reduce the harmful effects of TiO₂ NPs, especially airway mucus secretion, remains unexplored. One of the potential candidates to reduce airway mucus secretion is cerium oxide (CeO₂) NPs. It has been reported that CeO₂ NPs can protect cells by diminishing ROS and inflammatory responses. Herein, our study shows that CeO₂ NPs are able to reduce cytosolic Ca²⁺ changes and mitochondrial damage caused by TiO₂ NPs. Our results provide the evidence that hypersecretion of mucus and apoptosis progression induced by TiO₂ NPs can be attenuated by CeO₂ NPs. This study highlights the potential capacity of CeO₂ NPs as a supplementary material for TiO₂ NPs applications in the future.