In vitro copper oxide nanoparticle toxicity on intestinal barrier

Area of Science:

• Nanotechnology
• Materials Science
• Toxicology

Background:

• Copper oxide nanoparticles (CuO NPs) are increasingly used, necessitating investigation into their human health impacts.
• Caco-2 cells serve as a model for the human intestinal epithelium, crucial for assessing nanoparticle toxicity.

Purpose of the Study:

• To evaluate the effects of commercial and sonochemically synthesized CuO NPs on Caco-2 cell barrier integrity and inflammatory responses.
• To compare the toxicity of CuO NPs synthesized via different methods (sonochemical vs. commercial) and exposed via different cellular compartments (apical vs. basolateral).

Main Methods:

• Caco-2 cells were exposed apically (Ap) or basolaterally (Bl) to varying concentrations of commercial or sonochemically synthesized CuO NPs (in ethanol or water).
• Transepithelial electrical resistance (TEER) was measured over 24 hours to assess barrier function.
• Cytokine release (IL-8, IL-6, TNF-α) and protein oxidative damage biomarkers were analyzed.

Main Results:

• Sonochemical CuO NPs induced a dose-dependent decrease in TEER after basolateral exposure.
• Apical exposure to commercial CuO NPs did not affect TEER, while basolateral exposure showed minimal impact at 10 μg/mL after 24 hours.
• Increased interleukin-8 release was observed with sonochemical CuO NPs (apical) and both types of CuO NPs (basolateral).
• Apical treatment with commercial and water-based sonochemical CuO NPs altered protein oxidative damage biomarkers.

Conclusions:

• Sonochemical synthesis methods yield CuO NPs with greater potential to disrupt intestinal barrier function and induce inflammation compared to commercial CuO NPs.
• The route of exposure (apical vs. basolateral) significantly influences CuO NP toxicity.
• CuO NP exposure can lead to oxidative damage to proteins within intestinal cells.