Non-invasive Longitudinal Tracking of Human Amniotic Fluid Stem Cells in the Mouse Heart

Human stem cells from various sources have potential therapeutic applications. The clinical implementation of these therapies introduces the need for methods of noninvasive tracking of cells. The purpose of this study was to evaluate a high resolution magnetic resonance imaging (MRI) technique for in vivo detection and tracking of superparamagnetic micron sized iron oxide particle (MPIO)-labeled human amniotic fluid stem (hAFS) cells injected in the mouse heart. Because of the small subject size, MR signal and resolution of the in vivo MRI were increased using strong gradients, a 7.0 Tesla magnet, and an ECG and respiratory gated gradient echo sequence. MRI images of mouse heart were acquired during a 4 week course of this longitudinal study. At the end of the study, histological analysis was used to correlate cell localization with the MRI results.Introduction of MPIOs into hAFS had no significant effect upon cell proliferation and differentiation. Results of flow cytometry analysis indicated that hAFS c...