Figure 3.

In vitro and in vivo studies to identify paramagnetic contrast agents labelling the iPS‐MSCs and in vivo cell tracing by MRI in living animals. A, Illustrating the results of Prussian stain for identification of stepwise increased dosage of FeraTrack™Direct Kit for identification of paramagnetic contrast agent labelled in the iPS‐MSC (ie iPS‐MSC^SPIONs) (ie grey colour). Upper panel indicated the images in bright field; lower panel indicated the images of Prussian blue‐stained cells. B, The cell viability did not affect by the stepwise increased in concentration of paramagnetic contrast agent labelling. C to G, Illustrating the magnetic resonance imaging (MRI) examination of kidney among the five groups. The results showed that the iPS‐MSC^SPIONs (red arrows) were only identified in CKD + intravenous administration of iPS‐MSC^SPIONs animals. H to L, MRI contrast study also elucidated the expression of iPS‐MSC^SPIONs was only observed in CKD + iPS‐MSC animals (green arrows). M to Q, By day 60 after CKD induction, Prussian stain (200x) demonstrated that the iPS‐MSC^SPIONs (ie iron positively stain (blue colour) (green arrows)) were only identified in CKD + iPS‐MSC animals. Scale bars in right lower corner represent 50µm. iPS‐MSC, induced pluripotent stem cells‐derived mesenchymal stem cells; iPS‐MSC^SPIONs, the iPS‐MSC was labelled by paramagnetic contrast agent; SC, sham‐operated control