A New Biomaterial Heals Heart Attack Damage In Animals. Humans Could Be Next

New biomaterials delivered to the heart immediately after a myocardial infarction can heal damaged tissue from within.

A heart attack kills heart muscle tissue, damaging the heart and leaving permanent damage in just six hours. The damage impairs the proper functioning of the heart. If there's a chance for damaged tissue to begin healing immediately after a heart attack, doctors may be able to prevent scar tissue from developing.

"In an ideal world, when patients are having a heart attack, you treat them as soon as they have a heart attack to try to save some tissue and promote recovery," says bioengineer Karen Christman of the University of California, San Diego.

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The pursuit of this ideal inspired Christman to develop biomaterials with a research team. In rodents and pigs, it repairs tissue damage and reduces inflammation immediately after cardiac arrest, Christman and colleagues report December 29 in Nature Biomedical Engineering .

"I think it has a lot of potential," said biomedical scientist Vimala Bharadwaj of Stanford University, who was not involved in the research. The paper was "definitely a good proof of concept for what they were trying to do".

Previously, researchers found that stem cells derived from body fat could be used to heal bones, muscles and the heart ( SN: 9/3/16 ). Christman wanted to work with the extracellular matrix, the protein network that provides structural support to heart muscle tissue cells. Like stem cells, it has regenerative abilities but is much cheaper, he said.

In 2009, Christman's team used these matrix particles to create a hydrogel. Tests on mice and later humans showed that the ingredient binds to damaged areas and promotes cell repair and growth. However, since the hydrogel particles are relatively large, they can only be delivered to the heart through a needle.

"Pricking the heart with a needle can cause an arrhythmia," says Christman. Before using this medicine, doctors must wait several weeks until the heart is unstable and the irregular heartbeat has subsided. And it will be too late to prevent scars.

The team took the hydrogel they had previously made, centrifuged the larger particles so that only the nanoparticles remained, and added water to dilute the mixture. This creates a material thin enough to be delivered intravenously into a heart vein.

Based on the size of the nanoparticles, the team calculated that the mixture would pass through the heart's blood vessels caused by a heart attack and attach to the surrounding tissue. There it forms a protective barrier while the heart heals.

In contrast, animal studies have shown that extracellular matrix material binds to leaky vessels, preventing some inflammatory cells from invading heart tissue and causing further damage. The compound reduces inflammation in the heart and promotes the healing process by stimulating cell growth, the team reported.

Further safety studies are required to prepare the biomaterial for clinical trials. First human studies likely to regenerate heart tissue after a heart attack. “A big part of my motivation is taking things out of the lab and into the real world,” says Christman.

Another real-world application for the biomaterial could be treating blood vessels in other hard-to-reach organs, including the brain after traumatic injury, Christman noted.

While Bharadwaj believes the dietary supplement has promising potential, tests are needed to determine whether the biomaterial improves headaches and cognitive or memory deficits in the brain following a traumatic injury. Whether it really is an effective TBI treatment needs to be evaluated.