Led by Harald C. Ott, MD, a joint research study from Harvard Medical School and Massachusetts General Hospital has grown 73 full-sized, beating human hearts from adult skin cells. The study was published in a recent issue of the journal Circulation Research. Until now, one of the biggest challenges in heart transplants is the high risk of the recipient’s body rejecting the donor heart. What this study has demonstrated is a technique called decellularization, in which untransplantable cells are stripped away from a donor heart, leaving behind a heart “skeleton” or architectural framework.
Using a fascinating new messenger-RNA technique, the scientists are now able to trick adult human stem cells into becoming pluripotent stem cells — the type of early-stage “genesis” stem cells that can develop into any type of cell in the human body (i.e. bone cells, heart cells, liver cells, brain cells, skin cells, etc.). Once the heart scaffolding is prepared and carefully approved, it is placed inside a bioreactor where it is reseeded with human cardiomyocytes derived from the induced pluripotent stem cells, then cultured with a nutrient solution for two weeks with the same environmental conditions that exist around a living heart’s real home in the upper left rib cage of a human chest. When it’s ready, the newly grown heart is shocked with electricity and it begins to beat. The team made 73 of these new hearts altogether.
In a press release the team says the next phase of the research is to build the new hearts fully from scratch without the need for scaffolding. This will require finding a way of producing a higher yield of pluripotent stem cells, which the team is already busy working on. Looks like 100% brand new custom-made, lab-grown hearts are right around the corner. To learn more about the Ott Lab’s state-of-the-art research into growing new human organs (including lungs, kidneys, trachea/larynx, and more) visit OttLab.mgh. (Image credit: Bernhard Jank, MD, Ott Lab, Center for Regenerative Medicine, Massachusetts General Hospital)