Scientists Grow Beating Human Heart Tissue From Stem Cells

Scientists have grown beating human heart tissue in a laboratory using stem cells.

The engineered tissue could be used as a model of a human atrium (upper chamber), allowing researchers to test out new drugs as part of preclinical screening. This could lead to a faster, more efficient method of developing new treatments for heart conditions like atrial fibrillation—where a person has an irregular heartbeat that can increase the risk of stroke and heart failure.

Thomas Eschenhagen, from the University Medical Center Hamburg-Eppendorf, Germany, and colleagues were building on research to develop cardiomyocytes—cardiac muscle cells. Initially, scientists developed heart cells based on chickens, rats and mice. Since 2011, they have been working with human stem cells to create cardiomyocytes.

In the latest study, published in the journal Stem Cell Reports, the team shows how it was able to culture 3D heart tissue that can beat, express genes and respond to drugs in a similar way to an actual human heart. To create the heart tissue, the team treated stem cells with a vitamin A metabolite (a substance involved in metabolism), which converted them into heart cells.

"Our human heart muscle strips in the dish come closer to human physiology, making the predictive value of these tests better than existing animal experiments," he told Newsweek.

Eschenhagen said that while they are not perfect, the structure and function of the cardiomyocytes is very close to that of real human heart muscle. An added benefit, he said, is that the engineered tissue can be used over the course of several weeks—"something you can't do with any other method. We are pretty excited about it and have numerous labs worldwide following us, including the FDA."

The team does not envisage growing an entire human heart—"I personally think that the goal is too ambitious," Eschenhagen explained. However, they do believe it could be used to create engineered heart muscle patches. They are currently looking at pig models for this work and hope to move onto humans.

"[Another] big question which we will answer soon is whether [stem cell]-derived cardiomyocytes/engineered heart tissues may be useful for predicting individual heart muscle function, e.g., in patients with inherited cardiac disease," he said.

Marta Lemme, first author of the study, said in a statement: "For us, the next step is to test various means to induce arrhythmias, study mechanisms of electrical remodeling of atrial fibrillation and test new potential drugs."