As you read this sentence, on average at least one person in the US will have started to clutch her chest. The blood flow to her heart will become blocked and cardiac muscle cells will start to die off and get replaced with scar tissue. This person has just suffered a heart attack and most likely will go on to develop heart failure, a weakening of the heart’s ability to pump blood and oxygen. In five years time, there’s a 50/50 chance she’ll be dead.
There are currently no treatments that can repair the damage associated with this so-called ‘myocardial infarction’ (MI), but a potential solution is now showing promise in a large-animal model. A team of bioengineers at the University of California–San Diego (UCSD) has now developed a protein-rich gel that appears to help repair cardiac muscle in a pig model of MI.
The researchers delivered the hydrogel via a catheter directly into the damaged regions of the porcine heart, and showed that the product promoted cellular regeneration and improved cardiac function after a heart attack. Compared to placebo-treated animals, the pigs that received a hydrogel injection displayed a 30% increase in heart volume, a 20% improvement in heart wall movement and a 10% reduction in the amount of scar tissue scar three months out from their heart attacks. “We hope this will be a game-changing technology that can actually prevent heart failure after heart attack,” says UCSD’s Karen Christman, who led the study.
Christman and her team developed their hydrogel by stripping muscle cells from pig hearts, leaving behind a network of proteins that naturally self-assembles into a porous and fibrous scaffold upon injection into heart tissue. They previously tested its safety and efficacy in rats, where they found increased cardiac function and no toxicity or cross-species reactivity.
Similar strategies using naturally-derived scaffolding, such as small intestinal submucosa from pigs inwound patching, are well established. The UCSD study now shows the clinical potential of this approach for cardiac regeneration after a heart attack in a large animal that more approximates humans. Christman has already formed a company based on the technology, called Ventrix, and she hopes to move the product into human safety trials within the year.