While a heart attack victim might recover from the event, their heart often ends up scarred. This scarring, rather than being superficial like on the skin, can make the heart pump less effectively and eventually cause it to fail. Now scientists have developed a prototype patch that could enable cardiac muscle to regenerate and prevent the development of scar tissue.
Using a collagen patch infused with a specific protein, the researchers were able to stitch the patch onto the hearts of mice and pigs that had undergone a heart attack. They found that it encouraged the growth of healthy cells and even blood vessels, helping supply the new tissue with oxygen and nutrients. Ultimately, this reduced the amount of scarring. “This finding opens the door to a completely revolutionary treatment,” says Pilar Ruiz-Lozano, who led the research published in Nature.
Most people now survive heart attacks, but little work has been done on the lasting damage, which can lead to long-term disability and even death. It was to this problem that Ruiz-Lozano and his team at Stanford turned their attention. They started by looking at other species of animals, such as fish, that can naturally regenerate their heart muscle if it becomes damaged. They found that in these species the outside layer of the heart, called the epicardium, stimulated existing heart muscle cells to replicate.
To figure out exactly what compounds might be responsible for this incredible regenerative ability, they then used mass spectrometry to identify over 300 proteins in the epicardium that they thought might play a role. From further testing and screening, the team was able to whittle down this list to just a single protein that encourages the cell growth: Follistatin-like 1 (FSTL1).
It was this protein that went on to form the core of the prototype patch developed by the team. The researchers used a piece of collagen and infused it with FSTL1. This gave the therapeutic patch the flexibility of fetal heart tissue, alongside the ability to slowly release the protein directly onto to the heart muscle over time. It also means that the body would not reject the implant, removing the need to give the patient immunosuppressive drugs. In fact, over time the patch becomes incorporated into the body.
So far, they’ve succeed in using the patch on mice and pigs that have suffered heart attacks. They found that the heart function was restored to close to normal levels just four to eight weeks after implanting it. The researchers now hope they can move onto human clinical trials by as early as 2017.