Multiparametric viability tests of Caco-2 cells exposed for 72 h to 10 μg/mL TiO
STNPs. Caco-2 cells were grown in 24-well plates and differentiated for 21 days. The cells were exposed for 72 h to various TiO2 STNPs at 10 μg/mL. Cell viability was determined by counting the number of viable cells with trypan blue on Cedex (Innovatis), by XTT mitochondrial assay and with ATP measurement. Experimental positive control was obtained by exposing cells to H2O2 2.5 mM.