Table 1.

Particle characteristics

	Size DLS [nm]	Size TEM [nm]	Z-potential [mV]
in H2O	138 ± 62	30–40	26.5 ± 0.3
ALIa	67 ± 25	partially agglomerated	n.d.
in CCM	1000 ± 400	100–2000	n.d.

The ZnO-NP suspension (50 % in H₂O, average mean size 35 nm, < 100 nm (DLS)) was obtained from Sigma and characterized in H₂O as well as in cell culture medium (CCM; RPMI + 10 % FCS). Zeta potentials were not determined (n.d.) in PBS or CCM

^aDLS: prior to nebulization in NaCl solution; TEM: after nebulization