Titanium dioxide nanoparticles translocate through differentiated Caco-2 cell monolayers, without disrupting the...

Area of Science:

• Nanotechnology
• Cell Biology
• Toxicology

Background:

• Titanium dioxide nanoparticles (TiO2 NPs) are extensively used in food products.
• Intestinal cells, particularly Caco-2 cells, serve as a relevant model for assessing NP effects on the intestinal barrier.

Purpose of the Study:

• To evaluate the potential harmful effects of TiO2 NPs on human intestinal Caco-2 cells.
• To investigate TiO2 NP uptake, translocation, and impact on intestinal barrier integrity and genotoxicity.

Main Methods:

• Utilized undifferentiated and differentiated Caco-2 cell models.
• Assessed NP uptake and translocation via confocal and transmission electron microscopy with energy-dispersive X-ray spectroscopy.
• Monitored monolayer integrity using transepithelial electrical resistance and Lucifer yellow assays.
• Evaluated genotoxicity using the comet assay with and without formamidopyrimidine DNA glycosylase.

Main Results:

• TiO2 NP exposure (1-200 μg/ml) did not induce toxicity in Caco-2 cells.
• Undifferentiated cells showed higher TiO2 NP uptake compared to differentiated cells.
• TiO2 NP translocation across differentiated cell monolayers was observed.
• No significant alterations in monolayer integrity were detected.
• Genotoxicity assays revealed minimal changes at low doses (10 μg/ml) but no effects at higher doses.

Conclusions:

• TiO2 NPs do not appear to cause significant toxicity or compromise intestinal barrier function at the tested concentrations.
• Further research may be needed to fully elucidate long-term effects and mechanisms at lower, chronic exposure levels.