Figure 4.

Application of transfection agents to encourage a swift uptake of magnetic nanoparticles by stem cells.

Notes: Conjugating protamine to magnetic nanoparticles (Feridex; Ad-Vance Magnetics Inc, Rochester, IN, USA) significantly improved the uptake of the nanoparticles by the mesenchymal stem cells. The nuclei of the stem cells are labeled in blue, with white arrows identifying some of the magnetically labeled cells; the superparamagnetic iron oxide nanoparticles were detected using anti-dextran antibodies. The image shows the mesenchymal stem cells with protamine only (A), with magnetic nanoparticles in the absence of protamine (B), and with magnetic nanoparticles of a protamine at concentrations of 1 μg/mL (C) and 5 μg/mL (D). Scale bar is 50 μm. Springer and Methods Mol Biol, 906, 2012, 239–252, Labeling stem cells with superparamagnetic iron oxide nanoparticles: analysis of the labeling efficacy by microscopy and magnetic resonance imaging, Jasmin, Torres AL, Jelicks L, de Carvalho AC, Spray DC, Mendez-Otero R, Figure 2.²⁹ With kind permission from Springer Science and Business Media.