Fig. 1

The capacity of Ir-MNa coated in the hUC-MSCs during co-culture and identification of Ir-MNa by brain MRI at 4 h and 24 h after ICH induction. A–D at time point of 4 h and E–H at time point of 24 h Illustrated the microscopic finding (200 ×). Prussian Blue Stain for identifying the expression of stepwise increased dosages of ironic magnetic nanoparticles (Ir-MNa)-coated in human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) (blue color). The result showed that the Prussian Blue Stain for Ir-MNa in hUC-MSCs demonstrated more stronger expression as the concentration of Ir-MNa was increased. Additionally, the time point of 24 h was better than 4 h for Ir-MNa coating into the hUC-MSCs. Group 1 (G1) = hUC-MSCs coated with Ir-MNa (0 μM); group 2 (G2) = hUC-MSCs coated with Ir-MNa (50 μM); group 3 (G3) = hUC-MSCs coated with Ir-MNa (75 μM); group 4 (G4) = hUC-MSCs coated with Ir-MNa (100 μM). I–L Illustrating the brain magnetic resonance imaging (MRI) finding (i.e., for tracking and visualizing cells by MRI) at 4 h after acute ICH induction. As compared with normal (I) and ICH (yellow dotted line) + hUC-MSCs without Ir-MNa coating (J), the Ir-MNa coated hUC-MSCs (expressed as dark color area) without magnet over the rat head (K) was clearly identified in ICH area (green dotted line). On the other hand, as compared with (K) picture, more spacious dark-color area (in red dotted line area) of Ir-MNa coated hUC-MSCs with magnet over the rat head (L) were observed, suggesting that cells already homing in the hemorrhagic and ischemic regions even at a short time interval (i.e., 4 h) after they were administered. ICH = intracranial hemorrhage; hUC-MSCs = human umbilical cord-derived mesenchymal stem cells