Researchers have uncovered a means of making a new type of cell that is a cross between mature heart cells and embryonic stem cells, a discovery that may be the key to heart disease treatment.

Called induced expandable cardiovascular progenitor cells (ieCPCs), the cells turn into heart cells naturally while retaining their replicating abilities. Injected into a mouse that just had a heart attack, the ieCPCs dramatically improved functions in the heart.

This isn't the first time that researchers have turned to cell transplantation to address heart failure, but the problem with previous transplants was that the cells used were not capable of reproducing, eventually dying after the procedure.

The ieCPCs developed by the researchers, however, were not only able to replicate after being transplanted, but they were also able to grow into three cell types found in the heart.

For a study published in the journal Cell Stem Cell, the researchers were able to produce cardiovascular progenitor cells (CPCs), which naturally form as the heart grows in an embryo and lead to different heart cells. The CPCs were then gathered using pharmaceutical drugs and kept at the cardiac precursor state, the stage right before they turn into more specific heart cells.

Based on observations, the ieCPCs exponentially expanded over the course of several generations, resulting in the creation of enough cells that can be used to treat numerous people, if ever. Self-renewal is important in treating heart failure, because over a billion heart cells are lost after a heart attack occurs.

Aside from merely developing into three heart cell types (smooth muscle cells, endothelial cells and cardiomyocytes), the ieCPCs didn't need additional signals to direct what kind of cells they would develop into.

In the study, the researchers saw that up to 90 percent of injected ieCPCs in the mouse model developed into fully-functioning cells working with existing cells and created new blood vessels in the heart. This significantly improved the heart's function, allowing the organ to efficiently pump more blood.

The cells used in developing ieCPCs were skin cells, so the results of the study are a step toward personalized care, where heart cells can be made from a patient's own skin cells.