Visualization of survival and migration of transplanted stem cells by MRI

Abstract

Stem cell transplantation therapy has been becoming one of the most attractive medical treatments for repairing ischemic tissues in limbs, myocardial infarction and the brain. To understand the mechanism implicated during the healing, a cell tracking system under MRI would be very useful in the field of fundamental research and clinical applications. An MRI contrast agent composed of bioinert polymeric carriers such as poly(vinyl alcohol) or dextran and gadolinium chelate was synthesized by activating their hydroxyl groups with 1,1'-carbonylbis-1H-imidazole (polymeric-Gd). Three kinds of cells, NIH-3T3, rat bone marrow-derived mesenchymal stem cells (BMSCs) and rat endothelial progenitor cells (EPCs) were labeled with the polymeric-Gd by the electroporation under a very mild condition. The amount of the delivered contrast agent, cytotoxicity, and the intracellular stability of the polymeric Gd was evaluated in vitro. These labeled cells were injected hindlimb ischemia rat models and the MR contrast at a given amount of cells injected was evaluated. Our results revealed at the first time that the stem cell migration in the ischemic or nonischemic cells were very different and even the cell survival period of time after transplantation was greatly affected by the ischemic situation of the rats. © 2013 IFMBE.