Mechanistic Investigation of the Biological Effects of SiO2, TiO2, and ZnO Nanoparticles on Intestinal Cells

Silicon dioxide (SiO2), titanium dioxide (TiO2), and zinc oxide (ZnO) are currently among the most widely used nanoparticles (NPs) in the food industry. This could potentially lead to unintended exposure of the gastrointestinal tract to these NPs. This study aims to investigate the potential side‐effects of these food‐borne NPs on intestinal cells and to mechanistically understand the observed biological responses. Among the panel of tested NPs, ZnO NPs are the most toxic. Consistently in all three tested intestinal cell models, ZnO NPs invoke the most inflammatory responses from the cells and induce the highest intracellular production of reactive oxygen species (ROS). The elevated ROS levels induce significant damage to the DNA of the cells, resulting in cell‐cycle arrest and subsequently cell death. In contrast, both SiO2 and TiO2 NPs elicit minimum biological responses from the intestinal cells. Overall, the study showcases the varying capability of the food‐borne NPs to induce a cellular response in the intestinal cells. In addition to physicochemical differences in the NPs, the genetic landscape of the intestinal cell models governs the toxicology profile of these food‐borne NPs. The toxicity of food‐borne nanoparticles (NPs) is found to be governed by the physicochemical properties of the NPs and the genetic landscape of the cells. The different cellular responses of the various intestinal cell models may involve the production of reactive oxygen species (ROS). ZnO NPs are found to activate multiple pathways leading to a myriad of cellular responses, including cell‐cycle arrest, inflammatory‐gene activation, and cell death.