Medical Research

Stem cell patches heal damaged heart muscles

Damaged heart cells can be regenerated with lab-grown stems cells:study
German researchers grow stem-cell patches for heart muscle regeneration

HQ Team

January 30, 2025: Heart disease remains one of the leading causes of mortality worldwide, often resulting in irreversible damage to cardiac tissue. Recent advancements in stem cell research offer hope for regenerating damaged hearts, potentially transforming the landscape of cardiovascular treatment.

A clinical trial has demonstrated the efficacy of stem cell-derived muscle patches in the remusculation of damaged hearts.

In a study published in Nature, researchers in Germany successfully implanted patches of muscle grown from stem cells onto the heart of a 46-year-old woman suffering from heart failure after a heart attack. The procedure involved grafting ten patches, each containing approximately 400 million cells, onto the surface of her heart. Remarkably, the patient’s condition stabilized for three months, allowing her to await a heart transplant. Post-surgery examinations revealed that the implanted patches not only remained in place but also developed their own blood vessels, indicating successful integration into the heart tissue.

Implanting lab-grown muscles

Ingo Kutschka, a co-author of the study and a heart surgeon at University Medical Center Göttingen, emphasized the significance of this development: “For the first time, we have a laboratory-grown biological transplant available that has the potential to stabilize and strengthen the heart muscle.”.

The lab-grown cardiac tissue can then be grafted onto beating hearts to help them repair. It is like “implanting young muscle,” says Kutschka.

Regenerating capacities

The adult human heart is made up of approximately five billion heart cells, which can be damaged by cardiovascular diseases. Traditionally, the heart was thought to be a postmitotic organ, incapable of regeneration. However, recent studies found that the heart has some limited regenerative capacity, and 15% of cardiomyocytes (CMs) can regenerate following injury.

Researchers are harnessing both embryonic stem cells and induced pluripotent stem cells (iPSCs) to generate new heart cells. iPSCs, particularly, have shown remarkable potential due to their ability to differentiate into various cell types, including cardiomyocytes and endothelial cells necessary for forming blood vessels. 

Previous studies 

Research led by bioengineers at the University of Alabama at Birmingham has shown that iPSC-derived cardiomyocytes can effectively integrate into damaged heart areas, restoring function and reducing scar tissue. The study demonstrated that human embryonic stem cell-derived cardiomyocytes could re-muscularize infarcts in primate hearts, significantly improving their pumping ability. His team reported that treated animals experienced an increase in ejection fraction—an important measure of heart function—indicating that new muscle tissue had formed within previously scarred areas.

Constraints and future directions

In the present study, trials on monkeys found the patches were good at contracting, enhancing, and thickening the heart wall, which improved the pumping of the whole heart. 

On the downside, patches of the engineered heart muscle have to survive in the patient and be nurtured over several months, so they are not useful for people who need emergency care.

The study also encountered problems with some leftover cells from the cartilage/bone stage, suggesting that there were still a few stem cells in the sheets that were not committed to a mature state.

One animal developed an immune reaction to the implanted cells in the animal study despite being treated with immunosuppressives. Also, it was an unexpected reaction, as the scientists hoped that treatment with one’s own stem cells would overcome such a reaction. 

The researchers have more to learn from the current human trial and plan a long-term follow-up of 15 patients to find out more about the health of those living with the patches for years.