Figure 6.

A549 cells incubated with TiO₂ NMs in FITC-labeled serum, followed by a post-incubation period in Alexa-647-labeled serum for 15 min (0 h) and 18 h prior to fixation and confocal imaging. (A) Uncoated TiO₂ NMs (TiO₂-un) demonstrate a loss of the FITC signal by 18 h, suggesting a loss of the initial corona. Alexa-647-labeled serum remains bound to TiO₂-un at 18 h, suggesting that the loss of the initial corona signal is likely to be a consequence of protein exchange. (B) AA4040 Dispex-coated TiO₂ NMs (TiO₂-AA4040) demonstrate markedly different spot sizes after internalization at 18 h and retain their initial corona, suggesting that surface modification can play a significant role in the corona exchange kinetics and uptake of TiO₂ NMs.