An Investigation to Study the Toxicity of Titanium Dioxide (TiO2) on Human Intestinal Cells (Caco-2)
Emesowum, Benedict; Wojeck, Brian; Koeneman, Brian; and Capco, David
School of Life Sciences, Arizona State University
The proliferation of many types of nanoparticles for industrial, cosmetic, and pharmacological applications has led to heightened concerns over the potential toxicity of such revolutionary substances. Since little is known about the negative effects these nanoparticles may possess, there is need to study their potential toxicity. Nanoparticles are between 1-100nm in size. Due to manipulation at the nanoscale, the resulting nanoparticles possess certain physical and chemical characteristics that lead to high reactivity within cells. Titanium dioxide (TiO2) is used in water and air remediation and in products such as sunscreens, toothpastes, cosmetics, and paints. Also, titanium dioxide reportedly triggers rapid and long-lasting immune responses in mouse microglia. Since epithelial cells of the gut are some of the first cells exposed to such nanoparticles and act as protective membranes for the body, it was reasonable to test the effect of TiO2 on human intestinal epithelial cells using Caco-2 cell lines as model systems. The short and long term effects of TiO2 nanoparticles on membrane integrity and cell death of a monolayer of Caco-2 cells was tested. This was done using media, containing different concentrations (in parts per million) of TiO2 nanoparticles, to feed a monolayer of Caco-2 cells anchored on a filter in a well chamber. Other tests investigated the tendency of the nanoparticles to agglomerate/aggregate in or on the cells as well as whether the TiO2 nanoparticles trigger/hinder certain kinase activities in the intestinal cells.