Major improvements made in engineering heart repair patches from stem cells

The study findings, he observed, suggest that researchers consider including blood vessel-generating and vascular-supporting elements when designing human tissues for certain other types of regenerative therapies unrelated to heart disease.

One of the major obstacles still to be overcome is the likelihood that people's immune systems would reject the stem transplant unless they take medications for the rest of their lives to suppress this reaction. Murry hopes someday that scientists would be able to create new tissues from a person's own cells.

"Researchers can currently turn human skin cells back to stem cells, and then move them forward again into other types of cells, such as heart muscle and blood vessel cells," Murry said. "We hope this will allow us to build tissues that the body will recognize as 'self.'"

While the clinical application of tissues engineered from stem cells in treating hearts damaged from heart attacks or birth defects is still in the future, the researchers believe progress has been made. This study showed that researchers could create the first entirely human heart tissue patch from human embryonic cell-derived heart muscle cells, blood vessel lining cells and fiber-producing cells, and successfully engraft the tissue into an animal.

Future studies will try to move heart cell regeneration closer toward clinical usefulness, according to Murry and his research team. They forecast that such research would include testing other sources of human cells and developing techniques to create bigger patches for treating larger animals through surgical transplantation or through catheter delivered injections.

Lastly, they concluded, researchers would need to test whether tissue patches actually improve physical functioning after implantation in damaged hearts.

University of Washington researchers in the Chuck Murry lab at the UW Institute of Stem Cell and Regenerative medicine engineered this heart repair patch from a mix of stem cells. In a normal, living heart, electrical excitation triggers release of calcium in heart cells and subsequent muscle contraction to pump blood. The heart wall muscle is electro-mechanically coupled to make this synchronous activation pass across the entire tissue with each beat. This movie shows synchronous sweeps of calcium waves across the engineering heart repair patch, thereby indicating that the cells areelectronically coupled.

(Photo Credit: Charles Murry Lab, University of Washington)

This heart repair patch was engineered from a mix of stem cells in the University of Washington laboratory of Dr. Charles Murry. The tissue patch is shown beating spontaneously and synchronously in a lab dish.

(Photo Credit: Charles Murry lab, University of Washington)

This is Dr. Charles "Chuck" Murry, University of Washington (UW) professor of pathology working in a UW Institute of Stem Cell and Regenerative Medicine laboratory where studies are conducted to engineer heart repair patches from stem cells.

(Photo Credit: Clare McClean)

Source: University of Washington