An international team of scientists and engineers has developed a hydrogel patch specifically modeled to reduce damage to the heart in the aftermath of a heart attack.
Published in Nature Biomedical Engineering, the work is a collaboration between China's Soochow and Fudan Universities and Brown University in the US. The team created an adhesive patch made from food starch that can be placed directly on to the heart. On testing in rats, the patch was shown to prevent left ventricle remodeling - a stretching of the heart muscle that's common after a heart attack and can reduce the function of the heart's main pumping chamber.
"Part of the reason that it's hard for the heart to recover after a heart attack is that it has to keep pumping," said Huajian Gao, a professor of engineering at Brown and a co-author on the paper. "The idea here is to provide mechanical support for damaged tissue, which hopefully gives it a chance to heal."
Previous studies had demonstrated that patches for the heart could be effective at mitigating damage in the aftermath of attacks, but until now no one had tried to optimize their mechanical properties. According to Gao, the thickness and stiffness of potential patches are key to overall function.
"If the material is too hard or stiff, then you could confine the movement of the heart so that it can't expand to the volume it needs to," he said. "But if the material is too soft, then it won't provide enough support. So we needed some mechanical principles to guide us."
The researchers first used computer models to determine the desired levels of support, then turned to materials science to find a substance that could match the optimal properties. The starch-based hydrogel they developed is viscoelastic, meaning it combines fluid and solid characteristics. It has fluid properties up to a certain amount of stress, at which point it solidifies and becomes stiffer, meaning it provides the ideal level of support for the heart. The material is also non-toxic and cheap, with each patch costing less than a penny.
Biochemical markers showed that the patch reduced cell death, scar tissue accumulation and oxidative stress in tissue damaged by a heart attack in rats, with human trials potentially on the horizon.
"It remains to be seen if it will work in humans, but it's very promising," Gao said. "We don't see any reason right now that it wouldn't work."
