Environmentally Relevant Iron Oxide Nanoparticles Produce Limited Acute Pulmonary Effects in Rats at Realistic...

Area of Science:

• Environmental Science
• Toxicology
• Nanotechnology

Background:

• Iron oxide nanoparticles (FeO_xNPs) are common in airborne particulate matter.
• Previous studies on FeO_xNP toxicity yielded conflicting results.
• Existing research often lacks environmental relevance in particle characteristics.

Purpose of the Study:

• To assess the toxicity of environmentally relevant FeO_xNPs.
• To investigate Fe₃O₄ and mixed FeO_x forms due to preliminary cytotoxicity findings.
• To explore molecular responses using multi-omics in vitro and in vivo.

Main Methods:

• In vitro studies used human bronchial epithelial cells (BEAS-2B).
• In vivo studies involved Sprague-Dawley rats exposed via inhalation.
• Multi-omics analyses (transcriptomics, metabolomics) were performed at sub-cytotoxic concentrations.

Main Results:

• No clinical signs of toxicity were observed in rats.
• Bronchoalveolar lavage fluid (BALF) cell counts and LDH levels remained unchanged.
• No significant transcriptomic or metabolomic alterations indicating adverse effects were detected in lung or BEAS-2B cells.

Conclusions:

• Environmentally relevant FeO_xNPs, including Fe₃O₄ and FeO_x-mix, did not induce toxicity in vitro or in vivo.
• High-dose inhalation exposure did not elicit adverse clinical or molecular responses.
• The study suggests a low risk associated with exposure to these specific iron oxide nanoparticles.