The heart pumps blood to the entire body by repeated contraction and relaxation of the heart muscles. Human stem cells are used in the clinical therapies of a dead heart, which happens when a blood vessel is clogged or whole or a part of the heart muscle is damaged. The clinical use of human bone marrow-derived mesenchymal stem cells (BM-MSCs) has been expanded but failure of the transplanted stem cells in the heart still remains a problem.
A research team has developed a cardiac patch with bioink that enhances the functionality of stem cells to regenerate blood vessels, which in turn improves the myocardial infarction affected area.
The researchers mixed genetically engineered stem cells (genetically engineered hepatocyte growth factor-expressing MSCs, HGF-eMSCs) to make bioink in the form of a patch and introduced a new therapy by transplanting it to a damaged heart. The new strategy — called in vivo priming — refers to the principle that maximized function of MSCs is maintained in vivo as well as through its exposure to the growth factor secreted by the genetically engineered stem cells.
The team first genetically engineered the existing BM-MSCs to produce hepatocyte growth factor to improve the therapeutic potential of stem cells. The HGF-eMSCs were then mixed with BM-MSCs to make the bioink. They transplanted the cardiac patch with this bioink to the heart muscle affected by myocardial infarction. Considering the limited number of cells that could be transferred, they used heart-derived extracellular matrix bioink to make a cardiac patch.
Implanted cells in the patch survived longer in vivo and had more myocardiocytes survive than the only BM-MSCs transplanted experimental group. This was because the secretion of cytokine, which helps formation of blood vessels and cell growth, was maximized and delivered nutrients that promoted vascular regeneration and enhanced survival of the myocardiocytes.
The team anticipates that the new method could be a breakthrough treatment of myocardial infarction since the implanted stem cells through HGF-eM-SCs ultimately enhanced vascular regeneration and improved the myocardial infarction affected area.