Food-Grade TiO₂ Particles Generate Intracellular Superoxide and Alter Epigenetic Modifiers in Human Lung Cells

Area of Science:

• Toxicology
• Nanotechnology
• Cell Biology

Background:

• Titanium dioxide (TiO2) particles are widely used as a food additive for whitening.
• Previous research focused on ingestion, but inhalation effects on lung cells are less understood.
• Inhalation exposure is relevant for food industry workers and home users.

Purpose of the Study:

• To investigate the cellular response of lung cells to food-grade TiO2 particles upon inhalation.
• To determine if TiO2 particles induce oxidative stress and affect epigenetic modifications in lung cells.

Main Methods:

• Utilized fluorescence microscopy and RT-PCR to analyze lung cell responses.
• Investigated reactive oxygen species (ROS) generation, specifically superoxide.
• Examined changes in the expression of epigenetic modifiers, histone deacetylase 9 (HDAC9) and HDAC10.
• Employed a superoxide dismutase (SOD) protein corona to study the TiO2-superoxide relationship.

Main Results:

• Food-grade TiO2 particles induced intracellular superoxide generation in lung cells.
• TiO2 particles altered the expression of epigenetic modifiers HDAC9 and HDAC10.
• Even low, non-cytotoxic concentrations of TiO2 particles triggered significant cellular responses.
• The SOD corona experiments confirmed the link between TiO2 particles and superoxide production.

Conclusions:

• Inhalation of food-grade TiO2 particles at non-cytotoxic levels causes oxidative stress and alters epigenetic modifications in lung cells.
• The observed cellular responses, including superoxide production and changes in HDAC expression, may have implications for human health.
• Further in vivo studies are warranted to fully understand the pulmonary effects of inhaled food-grade TiO2 particles.