Scientists Grow Full-Sized Beating Human Hearts From Stem Cells

Scientists Grow Full-Sized Beating Human Hearts From Stem Cells

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So many people in the world are waiting for new hearts. And getting a heart doesn’t mean that the struggle is over. After a person gets a heart transplant, a new obstacle, just as perilous as the first, has to be overcome – will the body accept the new heart.

There are so many issues that need to be overcome, it’s overwhelming. However, a new scientific development just might hold the key to overcoming the greatest obstacles in human heart transplantation procedures.

Namely, a team of scientists from Massachusetts General Hospital and Harvard Medical School have made great strides in overcoming the major issues of organ shortage by using adult skin cells to regenerate functional human heart tissue.

What does this mean? Well, it means that they managed to grow a full-sized, beating human heart from stem cells.

According to their paper “Bioengineering Human Myocardium on Native Extracellular Matrix” published in Circulation Research, over 25 million people all over the world suffer from heart failure. Nearly 4000 patients a year in the US are on the waiting list for heat transplants, but only around 2500 per year will get the heart they need.

Thanks to this newly developed technique in which the scientists use adult skin cells to regenerate functional human heart tissue, there is much hope that one day everyone that needs a new heart, will get it and will be able to live a long and healthy life.

In their study, the scientists used a technique that was used in mouse hearts,  but this time they used it on human hearts. By stripping away many of the cell on 73 donatedhuman hearts that were recovered by the New England Organ Bank and were deemed unusable for clinical transplantation, the scientists were able to use their newly developed technique to turn them into pluripotent stem cells.

This means that these cells were turned into cells that can become specialized to any type of cell in the body. Then, these cells were induced to become two different types of cardiac cells that were grown under constant surveillance for two weeks.

 During those two weeks, the scientists infused the hearts with a nutrient solution and after the two weeks, the newly grown tissue looked like real human hearts that started beating only after they were given electricity shocks.

“To provide a clinically relevant tissue scaffold, we translated perfusion-decellularization to human scale and obtained biocompatible human acellular cardiac scaffolds with preserved extracellular matrix composition, architecture, and perfusable coronary vasculature,” the scientists state in their paper.

“We then repopulated this native human cardiac matrix with cardiomyocytes derived from nontransgenic human induced pluripotent stem cells and generated tissues of increasing 3-dimensional complexity.

We maintained such cardiac tissue constructs in culture for 120 days to demonstrate definitive sarcomeric structure, cell and matrix deformation, contractile force, and electrical conduction.”

It does sound promising, but the scientists say there is much more work to be done. Their next step is to boost the yield of pluripotent stem cells and quicken the growing process.

Also, they claim that the body-like conditions in which the hearts are grown, need to be perfected. All in all, this is a great leap for humanity – a ray of hope that one day everyone that needs a heart will get a heart and the possibility of a rejected heart transplant will be completely eliminated.

Sources:
http://circres.ahajournals.org/content/118/1/56
www.unos.org/data/transplant-trends/#waitlists_by_organ
http://emedicine.medscape.com/article/432209-overview#a4
https://www.eurekalert.org/pub_releases/2016-03/mgh-fhm031116.php

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