Keeping patients healthy after a heart attack is a challenge for cardiologists, but one day an injectable gel in development by researchers at the University of Pennsylvania might be just what the doctor orders.

Jason Burdick, a bioengineer who has led the latest design, said post-heart attack damage begins as enzymes known as matrix metalloproteinases, or MMPs, are released by the heart and break down healthy tissue.

"Eventually your heart actually expands and you see thinning of the myocardial wall and as a result of this you see a decrease in the overall function of the heart, [and] it's ability to pump blood to the rest of the body decreases," said Burdick.

Inhibitors block this remodeling process, but it's been difficult to localize them just to the heart. That's where the new gel comes in.

"Part of the material design that I think is fairly unique, is rather than just having them slowly diffuse from the gel, we designed gels that would degrade only in the presence of these MMPs," said Burdick.

The gel is made from sugar molecules that can respond to the heart enzymes, releasing an inhibitor to neutralize them precisely where they are the most concentrated.

Although clinical trials in people are several years way, Burdick found his gel improved heart function in pigs after a heart attack.

"Really, the important point here is that we had to intervene early," said Burdick. "So that we're really preventing these negative things from occurring, or attenuating how bad they are, rather than taking a heart that's undergone remodeling and then trying to treat it."

According to Burdick, the treatment might also prove useful for other cases where enzymes cause problems, such as osteoarthritis.