Scientists have grown a beating human heart using stem cells

Building a beating human heart in a lab with stem cells

A team of scientists have grown a beating human heart in a laboratory and they did it with stem cells.

The heart transplant list in the United States is massive, at any given time there is more than 4,000 people waiting for a new heart.

With a giant donor shortage not all patients are likely to survive because of a lack of transplants.

If scientists can figure out how to grow human hearts, it could change the way heart transplant patients are treated.

A new study in the journal Circulation Research has moved the practice of laboratory built hearts one step closer to reality.

Previous research has shown how 3D printers can be used to manufacture 3D heart segments using biological material. Although vacant of any actual heart cells, these structures provided the “scaffold” on which heart tissue could be grown.

This new research from a team at Massachusetts General Hospital (MGH) and Harvard Medical School has taken this scaffolding concept and combined it with stem cells for some truly spectacular results.

For this study, 73 human hearts deemed unsuitable for transplantation were carefully immersed in solutions of detergent in order to strip them of any cells that would provoke a self-destructive response, also known as rejection.

What was left was a matrix (or “scaffold”) of a heart, complete with its intricate structures and vessels, providing a new foundation for new heart cells to be grown onto.

In just two weeks the networks of lab-grown heart cells already resembled immature but intricately structured hearts. The team gave them a burst of electricity, and the hearts actually started beating.

“Among the next steps that we are pursuing are improving methods to generate even more cardiac cells,” said Jacques Guyette, a biomedical researcher at the MGH Center for Regenerative Medicine and lead author of the study, in a statement.

This first attempt used 500 million stem cell-derived heart cells for the procedure. A full heart will require “tens of billions” of stem cell-derived heart cells to complete, the research team says.

While the process is not perfected, it’s the closest anyone has come to building a human heart in a laboratory.