More than 800,000 Americans are expected to experience a heart attack this year. While many will survive, a significant number will be left with irreparable heart damage.
“Many tissues in your body, such as the skin or the liver, can multiply and grow back. But the heart muscle is unable to do that,” said UCLA cardiologist and professor Arjun Deb. “When your heart muscle dies, you lose that muscle forever.”
Researchers across the University of California (UC) system are working on new approaches to help hearts heal after injury. These projects have been made possible through federal funding and focus on moving beyond simply slowing damage, aiming instead to repair and regenerate heart tissue.
At UC San Diego, bioengineering professor Karen Christman has developed an injectable gel derived from extracellular matrix (ECM), a substance naturally found in the body that provides structural support for tissues. The ECM gel can be delivered into the heart shortly after a heart attack. “That stimulates the heart to have less scar tissue and preserve more cardiac muscle,” Christman explained.
A 2019 clinical trial showed that injecting ECM directly into the heart using a catheter was safe. Patients who received this treatment were able to walk faster than those who did not receive it, suggesting improved cardiac function. Christman is preparing for another clinical trial to test whether ECM can be delivered through blood vessels supplying the heart, which could make administration quicker and less invasive.
Another effort led by Dr. Arjun Deb at UCLA targets a molecule called ENPP1 in damaged hearts. After identifying its role in limiting energy supply during healing, Deb’s team created a compound that temporarily blocks ENPP1 activity following a simulated heart attack in animal models. Animals treated with this drug had significantly lower rates of developing heart failure compared to untreated animals—just 5 percent versus over 50 percent.
“This research represents a radical departure from existing lines of investigation which have led to the current drugs,” said Deb. Most medications used today slow down further tissue decline but cannot reverse existing damage; Deb’s drug aims to change that outcome.
Deb emphasized his gratitude for public investment: “My team and I are enormously grateful to the NIH for believing in us and we hope to deliver soon to the American people a new therapy for heart disease.” His work is currently being evaluated in early-stage human trials after receiving FDA clearance.
At UC Santa Barbara, researcher Martik is studying genetic similarities between humans and zebrafish—a species known for its ability to regrow damaged hearts—to find ways of activating dormant regenerative pathways in people. Using CRISPR technology on stem cell models of human hearts, Martik’s group seeks methods that could eventually enable human cardiac regeneration following injury.
Federal funding from agencies like the National Institutes of Health (NIH) has played an essential role in supporting these projects across UC campuses. Recent federal budget proposals included reductions for science agencies such as NIH, which advocates argued would negatively impact scientific progress and economic growth nationwide.
Through initiatives like UC’s Speak Up for Science campaign, community members contacted lawmakers urging them not to reduce funding levels. Last week Congress approved legislation maintaining bipartisan financial support for NIH and other research agencies for another year.
University officials continue encouraging public engagement with advocacy efforts as future budgets are considered so that medical research—and breakthroughs like those described above—can continue advancing patient care and scientific knowledge.
