Most heart attack survivors face a long and progressive course of heart failure due to damage done to the heart muscle. Now, in a study published in the journal Nature, researchers are reporting a method of delivering a missing protein to the lining of the damaged heart that regenerates heart muscle cells — cardiomyocytes — killed off during a heart attack.
The study, which was conducted in animal models, offers hope for future treatments in humans, according to the senior author of the study. "This finding opens the door to a completely revolutionary treatment," Pilar Ruiz-Lozano, PhD, told me. "There is currently no effective [way] to reverse the scarring in the heart after heart attacks."
The delivery system that researchers used in this study is a biodesigned tissue-like patch that gets stitched directly onto the damaged portion of the heart. The protein Fstl1 is mixed into the ingredients of the patch, and the patch, made of an acellular collagen, eventually gets absorbed into the heart leaving the protein behind. Our press release explains how the patch came to be:
The researchers discovered that a particular protein, Fstl1, plays a key role in regenerating cardiomyocytes. The protein is normally found in the epicardium — the outermost layer of cells surrounding the heart — but it disappears from there after a heart attack. They next asked what would happen if they were to add Fstl1 back to the heart. To do this, they sutured a collagen patch that mimicked the epicardium to the damaged muscle. When the patch was loaded with Fstl1, it caused new cardiomyocytes to regenerate in the damaged tissue.
In reading over the study, I was particularly interested in what an engineered tissue-like patch applied to a living heart looked like - and how exactly the patch got made. I called one of the study’s first authors and went to see him in his lab.
Vahid Serpooshan, PhD, a postdoctoral scholar in cardiology at Stanford, told me he can make a patch in about 20 minutes. It’s a bit like making Jell-O, he said; collagen and other ingredients get mixed together then poured into a mold. Serpooshan uses molds of various sizes depending on what kind of a heart the patch will be surgically stitched onto.
"The damaged heart tissue has no mechanical integrity," Serpooshan said. "Adding the patch is like fixing a tire... Once the patch is stitched onto the heart tissue, the cardiac cells start migrating to the patch. They just love the patch area..."
Previously: Stanford physician provides insight on use of aspirin to help keep heart attacks and cancer away, Collagen patch speeds healing after heart attacks in mice and Big data approach identifies new stent drug that could help prevent heart attacks
Image, of a patch stitched to the right side of the heart, by Vahid Serpooshan
