Cellular Effects of in Vitro-Digested Aluminum Nanomaterials on Human Intestinal Cells

Aluminum (Al) can be taken up from food, packaging or from the environment and reaches the human gastrointestinal tract. Its toxic potential after oral uptake is still discussed. The fate of different solid and ionic Al species during the passage through the digestive tract is in the focus of research, as well as the cellular effects caused by these different Al species. The present study combines the physicochemical processing of three recently studied Al species (metallic Al0, mineral Al2O3 and soluble AlCl3) in artificial digestion fluids with in vitro cell systems for the human intestinal barrier. Inductively coupled plasma mass spectrometry (ICP-MS) and small-angle X-ray scattering (SAXS) methods were used to characterize the Al species in the artificial digestion fluids and in cell culture medium for proliferating and differentiated intestinal Caco-2 cells. Cytotoxicity testing and cellular impedance measurements were applied to address the effects of digested Al species on cell viability and cell p...