Figure 5.
Effects of apical exposure to supernatants separated from zinc oxide (ZnO) nanoparticles (NPs) after incubation for 24 hours in fresh minimal defined serum-free medium (MDSF) or MDSF supplemented with 10% newborn bovine serum (MDS) on RT of MDSF (A)- or MDS (B)-grown rat alveolar epithelial cell monolayers (RAECMs) after 24-hour exposure (n = 3). The supernatants were obtained by centrifugation of ZnO NPs (11, 22 and 176 μg/ml) suspensions in MDSF or MDS. RT of MDSF- and MDS-grown RAECMs before supernatant exposure was 2.88 (±0.29) kΩcm2 (n = 9) and 2.16 (±0.16) kΩcm2 (n = 9), respectively. *Significantly different (P < 0.05) from control (RAECMs not exposed to ZnO NPs or supernatants).