Figure 4.

Confocal acquisition of A549 cells treated with (A) Pluronic-F127 (TiO₂-F127) and (B) Dispex-AA4040 (TiO₂-AA4040)-coated TiO₂ NMs and compared to the control (untreated cells) in FITC-labeled serum, followed by post-acquisition in unlabeled serum and fixation at 15 min (0 h), 2, 6, 18, and 24 h post-exposure. Compared to TiO₂-un- and TiO₂-PVP-coated NMs (Figure 3), these show significantly larger agglomerates which accumulate on the cell surface, and have been taken up into the cells by the 18 h time point, beyond which they appear to be retained.