Figure 2.

Long term stability of cell-labeling by nanoparticles. U118 glioma cells were incubated with different iron oxide nanoparticles for 24 h at an iron concentration of 0.2 mg/mL, washed and further cultivated. The cellular iron content was measured after different periods of time. Resovist showed the longest resting time, B102 the shortest. Initial iron concentration varied due to different initial labeling efficiencies, see Figure 1. n = 3 ± S.D.