Perovskite Nanoparticles Toxicity Study on Airway Epithelial Cells

Research on the toxicity of nanoparticles has developed over recent years due to their increasing prevalence in common everyday materials. Various nanoparticles have been reported to promote and induce mucus secretion, which could potentially lead to airway damages and respiratory complications. Lanthanum strontium manganite (LSM) is a nanoparticle widely used in solar oxidized fuel cells (SOFCs) due to its high electrical conductivity, high electrochemical activity for O₂ reduction reaction, high thermal stability and compatibility of SOFC electrolytes, and most importantly, its microstructural stability and long-term performance. Very few studies have been conducted on LMS's toxicity, thus its effect on airway cells was investigated in this study. After treating trachea cells with increasing concentrations of LSM ranging up to 500 μg/ml, we found that it has a moderate effect on cell viability, ROS production, cytochrome C, and caspase 3 expression. Despite its minimal impact on stated apoptosis-inducing characteristics, LSM illustrated an inhibiting effect on mucus secretion. We obtained a decreasing trend in mucus secretion with an increased concentration of the LSM treatment. Overall, LSM's advancement in SOFCs necessitated a toxicity study, and although it does not show a significant toxicity to trachea cells, LSM reduces mucus secretion, and can potentially interfere with airway clearance.

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.

[2 cases of acute cholestasis caused by ticlopidine]

We report the case of two patients suffered from cholestatic jaundice occurred 3-4 weeks after starting ticlopidine therapy. In both cases the diagnosis was made by ruling out any other known cause of acute hepatitis or cholestasis. One patient underwent liver biopsy, which showed a typical intralobular cholestatic pattern and a slight lymphocytic infiltration of the portal tracts. The other patient, a 29 year-old woman, was taking ticlopidine as the sole drug, further to an ischemic stroke occurred while she was taking oral contraceptives; she presented a diffuse itchy dermatitis, fever and slight eosinophilia besides cholestasis. In both patients ticlopidine was discontinued and liver tests returned to normal values within 4-8 weeks; no rechallenge was attempted and ticlopidine was replaced with another antiplatelet drug. To the best of our knowledge 19 cases of ticlopidine-related cholestatic disease have been described so far in the literature. Its pathogenesis is still unknown, although some clinical findings and experimental results from patients with acute enteropathy or agranulocytosis induced by ticlopidine suggest that the drug may act through a toxic mechanism, perhaps mediated by prostaglandins.