Ferritin Overexpression for Molecular Imaging of Transplanted Cells

Introduction Application of MR reporter genes is a new strategy in molecular imaging based on over-expression of non-toxic proteins responsible for in vivo uptake of MRI-detectable probes [1-2]. Gene-based production of contrast agents for MR cell tracking has many advantages over the standard approach using exogenous administration of superparamagnetic particles, where the imaging signal does not reflect cell viability and quantity [3]. Ferritin has been proposed as an endogenous MRI reporter for noninvasive imaging of gene expression in C6 glioma tumors [1] and for in vivo studies in the mouse brain [2]. The potential of using MR reporter genes to study fate of stem cells engrafted into infarcted myocardium has not been explored. We aim to develop genetically-based technique for molecular imaging of the MRI gene reporter ferritin to enable noninvasive assessment of cell survival and biodistribution after transplantation into infarcted rodent heart.