Figure 1. Iron oxide labeling of rabbit MSCs with MPIOs.

(a) Fluorescence microscopy image of a representative cell after overnight labeling. The dragon green fluorescence indicates cellular uptake of the iron oxide contrast agent, which is not present within the (b) representative unlabeled control cell. (c) (d) & (e) GRE imaging (TE/TR=8/500ms) of labeled cells (1×106cells/mL), unlabeled cells (1×106cells/mL), and empty Ficoll respectively. (f) (g) & (h) SE imaging (TE/TR=150/2000ms) of labeled cells (1×106cells/mL), unlabeled cells (1×106cells/mL), and empty Ficoll respectively. Both GRE and SE imaging demonstrate a visible signal loss associated with iron oxide labeling that is not present within unlabeled cells or the Ficoll solution alone. (scale bar=10μm)