Figure 5.

Comparison of the labeling efficiency of functionalized or nonfunctionalized nanoparticles at various iron concentrations.

Notes: INS-1 cells were cultured with nonfunctionalized PEG-USPIO for 24 hours at 10 μg/mL (iron concentration). The cell nucleus was stained by DAPI (A). The nanoparticles were observed by FITC (B). The merged (A and B) image is shown in (C). INS-1 cells were also cultured with functionalized USPIO for 24 hours at 10 μg/mL (D−F); 30 μg/mL (G−I); and 50 μg/mL iron concentration (J−L).

Abbreviations: DAPI, 4′,6-diamidino-2-phenylindole; FITC, fluorescein isothiocyanate; INS, insulinoma; PEG-USPIO, polyethylene glycol-coated ultrasmall superparamagnetic iron oxide; USPIO, ultrasmall superparamagnetic iron oxide.