Magnetic Targeting of Stem Cell Derivatives Enhances Hepatic Engraftment into Structurally Normal Liver.

Attaining consistent robust engraftment in the structurally normal liver is an obstacle for cellular transplantation. Most experimental approaches to increase transplanted cells' engraftment involve recipient-centered deleterious methods such as partial hepatectomy or irradiation which may be unsuitable in the clinic. Here, we present a cell-based strategy that increases engraftment into the structurally normal liver using a combination of magnetic targeting and proliferative endoderm progenitor (EPs) cells. Magnetic labeling has little effect on cell viability and differentiation, but in the presence of magnetic targeting, it increases the initial dwell time of transplanted EPs into the undamaged liver parenchyma. Consequently, greater cell retention in the liver is observed concomitantly with fewer transplanted cells in the lungs. These highly proliferative cells then significantly increase their biomass over time in the liver parenchyma, approaching nearly 4% of total liver cells 30 d after transplant. Therefore, the cell-based mechanisms of increased initial dwell time through magnetic targeting combined with high rate of proliferation in situ yield significant engraftment in the undamaged liver.