Biosafety influence of selected nano-packaging on the gastrointestinal tract of mice

Nanoparticles are widely used in various fields because of their unique physical properties, but the safety and health effects of nanoparticles in food packaging are unknown. We investigated the effect of oral exposure to various nanoparticles on gastrointestinal function. Titanium dioxide, zinc oxide, and silicon dioxide nanoparticles were orally administered to mice at 0, 25, 50, or 100 mg/kg/day. Body weight and ingestive behavior were documented and analyzed. Histopathology and immunohistochemistry were performed to assess the effects on gastrointestinal function. We found no evidence of toxicity in terms of general clinical signs, body weight, and macroscopic findings. Histopathology showed slight morphological variations in the tissues of the stomach and small intestine. Immunohistochemical analyses suggested that oral exposure to these nanoparticles does not affect the expression of the inflammatory cytokines interleukin 1β and interleukin 6. Low-dose and long-term exposure experiments should be conducted to assess factors affecting the toxicity of chronic exposure.