Interaction of mAb-functionalized magnetic nanoparticles with cells. GTL-16 and Huh7 cells were incubated with MNPs, functionalized or not with the DO-24 mAb (a) and (b), as well as with soluble mAb (b) for 2 h at 37 °C. After washing, staining was performed with Prussian blue (a); the first three panels on the left are 200× magnification and the forth on the right is 400× magnification for both cell types) or with FITC-labelled anti-mouse Ig (green), TRITC-labelled falloidin (red), TO-PRO3 (blue) to label the DO-24 mAb, the cytoskeletal actin and nuclei, respectively (b). Images were then merged. CTRL−, control untreated cells.