In vivo Tracking of Human Neural Stem Cells Following Transplantation into a Rodent Model of Ischemic Stroke

BACKGROUND AND OBJECTIVES: Ischemic stroke caused by middle cerebral artery occlusion (MCAo) is the major type of stroke, but there are currently very limited options for cure. It has been shown that neural stem cells (NSCs) or neural precursor cells (NPCs) can survive and improve neurological deficits when they are engrafted in animal models of various neurological diseases. However, how the transplanted NSCs or NPCs are act in vivo in the injured or diseased brain is largely unknown. In this study, we utilized magnetic resonance imaging (MRI) techniques in order to understand the fates of human NSCs (HB1.F3) following transplantation into a rodent model of MCAo. METHODS AND RESULTS: HB1.F3 human NSCs were pre-labeled with ferumoxides (Feridex(R))-protamine sulfate complexes, which were visualized and examined by MRI up to 9 weeks after transplantation. Migration of the transplanted cells to the infarct area was further confirmed by histological methods. CONCLUSIONS: Based on these observations, we speculate that the transplanted NSCs have the extensive migratory ability to the injured site, which will in turn contribute to functional recovery in stroke.

Study on MR tracking of magnetically labeled swine mesenchymal stem cells after autologous transplantation into acute injured liver in vivo / 中华肝胆外科杂志

Objective To evaluate in vivo tracking of swine mesenchymal stem cells (MSCs) la-beled with super paramagnetic iron oxide (SPIO) in intraportal transplantation by a clinical 1.5T MR.Methods MSCs were isolated from swine and cultured as well as expanded, which were then incuba-ted with SPIO (Feridex I. V.). Prussian blue staining was performed for showing intracelluar irons.To establish a swine model of acute liver necrosis, 0.5 g/kg of D-galactosamine was administrated to 10 pigs. MSCs(labeled cells in six, unlabeled cells in four)were injected into liver via portal veins. MR imaging was performed with a clinical 1.5T MR immediately before and at 6 h, 3 d, 7 d, 14 d after transplantation, respectively. Results Prussian blue staining of SPIO labeled MSCs could be effec-tively labeled and the labeling efficiency was almost 100%. Signal intensity loss in liver by SPIO labe-ling on FFE sequence persisted until 14 days after transplantation. Histological analysis by Prussian blue staining showed homing of labeled MSCs in liver after 14 days, primarily distributing in hepatic sinusoids and liver parenchyma. Conclusion MSCs can be labeled with SPIO in vitro successfully.MRI can monitor magnetically labeled MSCs transplanted into liver.

In vivo MR tracking of Feridex labeled bone marrow mononuclear cells in canine myocardial infarction / 中国医学影像技术

Objective To track the magnetically labeled bone marrow mononuclear stem cells (BM-MNCs) in canine myocardial infarction (MI) model with MR. Methods BM-MNCs were labeled with Feridex effectively in vitro and then injected intramyocardially in 8 MI model dogs. Serial MR was performed with 1.5T MR scanner to show the location of the labeled cells compared with histology. Results The injection sites of labeled BM-MNCs could be located on the 1st and 2nd week, but disappeared on the 4th week. Corresponding to these sites, Prussian blue staining consistently showed that large clusters of cells were labeled by dense intracellular iron at the scar tissue. Conclusion Feridex labeling BM-MNCs enables ready detection in the beating heart on a conventional MR scanner after transplantation into canine infarcted myocardium.