Toxicity of commercially available engineered nanoparticles to Caco-2 and SW480 human intestinal epithelial cells

The effects of ingestion of engineered nanoparticles (NPs), especially via drinking water, are unknown. Using NPs spiked into synthetic water and cell culture media, we investigated cell death, oxidative stress, and inflammatory effects of silver (Ag), titanium dioxide (TiO₂), and zinc oxide (ZnO) NPs on human intestinal Caco-2 and SW480 cells. ZnO NPs were cytotoxic to both cell lines, while Ag and TiO₂ NPs were toxic only at 100 mg/L to Caco-2 and SW480, respectively. ZnO NPs led to significant cell death in synthetic freshwaters with 1 % phosphate-buffered saline in both cell lines, while Ag and TiO₂ NPs in buffered water led to cell death in SW480 cells. NP exposures did not yield significant increased reactive oxygen species generation but all NP exposures led to increased IL-8 cytokine generation in both cell lines. These results indicate cell stress and cell death from NP exposures, with a varied response based on NP composition.