Scientists develop breakthrough injection to repair damaged hearts

In the quiet hours after a heart attack, a race begins inside the body. Heart muscle, starved of oxygen, begins to die. Scar tissue forms. The immune system, meant to help, can sometimes do more harm than good. 

For many survivors, this damage becomes permanent. It paves the way for heart failure — slow, irreversible, and often fatal.

But what if there was a way to stop this from happening?

A team of researchers led by bioengineers at the University of California, San Diego and chemists at Northwestern University may have found an answer. They have developed a new injectable therapy that can be delivered intravenously immediately after a heart attack.

The treatment prompts the immune system to repair tissue and protects heart muscle cells from dying. In rat models, the injection was shown to improve heart function and promote healing up to five weeks after the event.

The study, published in Advanced Materials, offers a promising new path. Professor Karen Christman, a lead author, calls it a step toward solving a major unmet need: preventing heart failure after heart attacks.

At the centre of the therapy is a polymer that mimics a naturally protective protein, Nrf2. Normally, a second protein, KEAP1, binds and degrades Nrf2. The synthetic polymer interrupts this process, protecting Nrf2 and giving cells a chance to recover.

Professor Nathan Gianneschi, the study's other lead author, believes the platform could treat a wide range of diseases linked to inflammation and stress.

The therapy is still in early stages. Researchers will now work to refine the design before moving to trials in larger animals. But in the quiet fight for life that follows every heart attack, this tiny injection may one day tip the balance.