Stem cells used to create heart muscle with blood supply

Scientists at the Technion-Israel Institute of Technology have created new heart muscle with its own blood supply using human embryonic stem cells. The team published its research online in the journal of Circulation Research.

Despite progress over the past two decades in treating cardiac disease, there are few good ways to fix damaged heart muscle. One possibility would be to use a transplant of healthy heart tissue, but the gap between demand for tissue and donors is continually increasing, and this has had a knock-on effect for research progress because of the lack of human heart tissue to work with.

The newly engineered muscle will promote research into novel applications for studies of cardiac development and function and the team, lead by Shulamit Levenberg and Lior Gepstein, believes that the technique has great potential. This new development could now make possible the replacement of tissue damaged in heart attacks, as well as also prove useful in engineering tissues for other organs such as the liver.

According to the researchers, they have developed the heart muscle by 'seeding a sponge-like, three-dimensional plastic scaffold with heart muscle cells and blood vessel cells produced by human embryonic stem cells, along with cells called embryonic fibroblasts'. This is done in order to improve the tissue's survival after being transplanted in a human heart.

Levenberg's research team used a similar technique in 2005 to grow skeletal muscle, and these studies have been helpful in designing the heart muscle - they showed that it was important to grow all the different cell types together on the scaffold, and that fibroblasts were key to supporting the blood vessel walls as they developed.

Several tests have been conducted to ensure that the new muscle looks and behaves like heart tissue. Four to six days after being seeded on the scaffold, patches of the new muscle cells began to contract together, a movement that spread until the entire tissue scaffold was beating like normal heart muscle.

To study how well the heart muscle adapts when transplanted into a new environment, the research will be taken further by transplanting the tissue into living hearts in animals.