In vitro intestinal epithelium responses to titanium dioxide nanoparticles

Area of Science:

• Toxicology
• Nanotechnology
• Gastroenterology

Background:

• Titanium dioxide (TiO2), also known as E171, is a widely used food additive in Europe.
• Concerns exist regarding the safety of TiO2 nanoparticles due to incomplete risk assessments.
• Emerging evidence suggests potential human health hazards from TiO2 exposure.

Purpose of the Study:

• To investigate the mechanisms by which nano-sized TiO2 particles impact the physiological function of the intestinal epithelium.
• To identify the biological responses triggered by TiO2 nanoparticles in a human intestinal model.

Main Methods:

• Utilized the Caco-2 cell line as a model for human intestinal mucosa, differentiated for 21 days.
• Exposed cells to 42 μg/mL TiO2 nanoparticles and assessed barrier integrity and effects over 4 and 24 hours.
• Employed ICP-OES, TEM, and ESI/EELS for nanoparticle transport and localization analysis.

Main Results:

• TiO2 nanoparticles disrupted tight junctions and permeability barrier function within 4 hours, with significant effects by 24 hours.
• Nanoparticles were efficiently internalized and stored within Caco-2 cells.
• Cellular storage of TiO2 nanoparticles impaired enterocyte viability and induced pro-inflammatory cytokine (TNF-α, IL-8) production.

Conclusions:

• Nano-sized TiO2 particles exert detrimental effects on the intestinal epithelium.
• Internalization and accumulation of TiO2 nanoparticles compromise barrier integrity and cellular health.
• Further research is warranted to fully understand the risks associated with dietary TiO2 exposure.