In vivo echocardiographic imaging of transplanted human adult stem cells in the myocardium labeled with clinically applicable CliniMACS nanoparticles

Objectives: Intramyocardial transplantation of bone marrow-derived cells is currently under clinical evaluation as a therapy of heart failure. A major limitation of all clinical studies dealing with myocardial cell engraftment is the inability to track the fate of the transplanted cells. We present a clinically applicable technique using transesophageal echocardiography (TEE) of CliniMACS nanoparticle labeled transplanted CD133(+) cells in ischemic hearts. Methods and Results: CD133(+) cells were isolated from human bone marrow by CliniMACS magnetic bead selection. Positive (5 x 10(6) cells) cells were transplanted into porcine ischemic myocardium (n = 6). Control animals (n = 5) received medium injection. TEE was performed to demonstrate the distribution of the cells during and 8 weeks after the procedure. Accumulations of labeled CD133(+) cells of adjacent injections in the myocardium were discriminatively identified by TEE. Conclusions: TEE is an elegant method for real-time documentation of successful transplantation and cell colony localization of magnetically labeled CD133(+) cells in the ischemic myocardium. Our method should be of special interest for TEE-guided transcatheter injection of cells.