Titanium dioxide induced inflammation in the small intestine

Area of Science:

• Nanotechnology
• Immunology
• Gastroenterology

Background:

• Titanium dioxide (TiO₂) is widely used in various industries.
• The impact of TiO₂ particle size on biological systems is not fully understood.
• Investigating the inflammatory effects of TiO₂ nanoparticles (NPTiO₂) and microparticles (MPTiO₂) is crucial.

Purpose of the Study:

• To compare the inflammatory effects of NPTiO₂ and MPTiO₂ in the mouse small intestine.
• To assess the impact of TiO₂ particles on immune cell populations and cytokine profiles.
• To determine if TiO₂ particle size influences the inflammatory response.

Main Methods:

• Male C57/Bl6 mice were gavaged daily with NPTiO₂ (66 nm) or MPTiO₂ (260 nm) at 100 mg/kg for 10 days.
• Control mice received distilled water.
• Small intestine segments (duodenum, jejunum, ileum) were analyzed for inflammatory cells (T cells, NK cells, dendritic cells) and cytokines (IL-1b, IL-4, IL-6, IL-12, IL-23, TNF-α, IFN-γ, TGF-β).

Main Results:

• Both NPTiO₂ and MPTiO₂ significantly increased CD4+ T cells in the duodenum, jejunum, and ileum compared to controls.
• TiO₂ administration led to elevated levels of inflammatory cytokines IL-12, IL-4, IL-23, TNF-α, IFN-γ, and TGF-β.
• The inflammatory cytokine production was more pronounced in the ileum, particularly for IL-12, IL-4, IL-23, TNF-α, IFN-γ, and TGF-β.

Conclusions:

• TiO₂ particles, regardless of size (nano or micro), induce a Th1-mediated inflammatory response in the mouse small intestine.
• The findings highlight the potential immunomodulatory effects of TiO₂ exposure.
• Further research is needed to understand the long-term implications of TiO₂ particle ingestion.