1
Ding W, Bai J, Zhang J, Chen Y, Cao L, He Y, Shen L, Wang F, Tian J. In vivo Tracking of Implanted Stem Cells Using Radio-Labeled Transferrin Scintigraphy. Nucl Med Biol. 2004, 31:719-725.
Abstract
The possibility of monitoring stem cells in vivo with radionuclide imaging after transplantation was investigated. Based on the results of a radioligand receptors assay that human mesenchymal stem cells (hMSCs) express a high level of transferrin receptors, iodinated transferrin (131I-Tf(Fe)2) was chosen as the radiotracer for imaging the cells implanted into the spinal cords of rabbits. Accumulation of radioactivity at the cell transplanted sites was assessed 16 and 24 hours post-intrathecal injection of 131I-Tf(Fe)2. Transferrin receptors expression and Tf binding of the implanted cells were verified by immunofluorescence and ex vivo phosphor imaging. The specificity of Tf uptake of hMSCs was proved through control experiments, i.e., replacing 131I-Tf(Fe)2 with 131I labeled human serum albumin as the tracer or substituting hMSCs with phosphate buffered saline as the grafts. Despite some defects, such as the invasive administration of the tracer and the non-specificity of transferrin receptors as a marker of stem cells in this preliminary study, the technique of nuclear medicine imaging is considered to have great potential in tracking implanted cells in vivo.
2
Bai J, Ding W, Yu M, Du J, Liu Z, Jia B, Li L, Shen L, Tian J, Wang F*. Radionuclide Imaging of Mesenchymal Stem Cells Transplanted into Spinal Cord. NeuroReport. 2004, 15(10):1117-1120.
In vivo tracking of stem cells implanted to spinal cord by radionuclide imaging was investigated. The high expression of transferrin receptor on human mesenchymal stem cells (hMSCs) was verified by flow cytometry, radioligand binding and immunofluorescence. Radiolabelled transferrin was chosen as a tracer for scintigraphic imaging of the hMSCs transplanted into spinal cord of rabbits. Comparative experiments with radiolabelled human serum albumin as tracer and PBS as graft as well as ex vivo autoradiography demonstrated the specific uptake of radiolabelled transferrin of hMSCs. hMSCs could be detected in vivowith radiolabelled transferrin targeting at cellular transferrin receptors at an early stage after transplantation into spinal cord.
http://dx.doi.org/10.1097/01.wnr.0000126505.97607.