In vivo priming of human mesenchymal stem cells with hepatocyte growth factor-engineered mesenchymal stem cells promotes therapeutic potential for cardiac repair.

The clinical use of human bone marrow-derived mesenchymal stem cells (BM-MSCs) has been hampered by their poor performance after transplantation into failing hearts. Here, to improve the therapeutic potential of BM-MSCs, we developed a strategy termed in vivo priming in which BM-MSCs are primed in vivo in myocardial infarction (MI)-induced hearts through genetically engineered hepatocyte growth factor-expressing MSCs (HGF-eMSCs) that are encapsulated within an epicardially implanted 3D cardiac patch. Primed BM-MSCs through HGF-eMSCs exhibited improved vasculogenic potential and cell viability, which ultimately enhanced vascular regeneration and restored cardiac function to the MI hearts. Histological analyses further demonstrated that the primed BM-MSCs survived longer within a cardiac patch and conferred cardioprotection evidenced by substantially higher numbers of viable cardiomyocytes in the MI hearts. These results provide compelling evidence that this in vivo priming strategy can be an effective means to enhance the cardiac repair of MI hearts.