Table 1.

Characterization of the used CeO₂ nanoparticles regarding shape, size, and ζ-potential

	With ATTO dyed	Without ATTO dyee
Shape	Octahedral/spheres	Octahedral/spheres
Size (nm)a	18.8 ± 4.5	18.8 ± 4.5
Size in H2O (nm)b	65 ± 1	79 ± 1
Size in cell culture medium (nm) shortly after preparationb,c	309 ± 9	369 ± 16
Size in cell culture medium (nm) after 3 h incubationb,c	307 ± 1	352 ± 6
ζ-potential in H2O (mV)	18.7 ± 0.5	18.4 ± 1.0
ζ-potential in cell culture medium (mV)c	−24.1 ± 0.3	−23.8 ± 0.6

^aBy TEM

^bBy DLS (polydispersity index <0.5)

^cCell culture medium supplemented with 10 % FBS

^dNanoparticles which were labeled with the dye ATTO 647 N-APS were used in flow cytometry analysis

^eUnlabeled counterparts were used for TEM and ICP-MS analysis