Heart attack survivors face a major clinical challenge: the injured cardiac tissue does not regenerate, leaving permanent damage that weakens the heart. Existing interventions, such as bypass surgery, improve blood flow but cannot repair the tissue itself. Now, researchers have developed a flexible, surgically implantable drug-delivery patch that restores heart function by releasing multiple therapeutics on a precise schedule.

The patch, developed by engineers at the Massachusetts Institute of Technology (MIT, Cambridge, MA, USA), is embedded with programmable drug-release microparticles into a biocompatible hydrogel sheet that can be placed directly onto the heart during open-heart surgery. The approach aims to synchronize therapy with biological healing phases following myocardial infarction.

The system relies on polymer-based PLGA capsules designed with “lid” materials of specific molecular weights, allowing each batch of particles to degrade and release its drug payload at distinct time windows: days 1–3, days 7–9, and days 12–14. This enables controlled delivery of neuregulin-1 to prevent cell death, VEGF to stimulate blood vessel formation, and the small-molecule GW788388 to limit scar-tissue development. These microparticle arrays are embedded within an alginate-PEGDA hydrogel patch only a few millimeters across, tough yet flexible enough to conform to the heart.

In laboratory testing using heart-tissue spheres composed of cardiomyocytes from induced pluripotent stem cells, endothelial cells, and ventricular fibroblasts, the patches promoted vascular growth, enhanced cell survival under low-oxygen conditions, and reduced fibrosis. In rat models of heart attack, the patches produced significant benefits compared with no treatment or intravenous drug delivery, including a 33% improvement in survival, a 50% reduction in damaged heart tissue, and markedly improved cardiac output.

The findings, published in the journal Cell Biomaterials, show that the hydrogel gradually degraded over a year, forming a thin layer without disrupting mechanical function. Practical future applications include placing the patch during bypass surgery to initiate timed cardiac-repair therapy immediately. The team is also exploring the incorporation of these microparticles into stents to enable scheduled drug release without the need for open-heart procedures. Neuregulin-1 and VEGF have both undergone previous clinical testing, while GW788388 has been evaluated only in animal studies. The researchers plan to continue testing the patch in larger animal models before pursuing human trials.

“When someone suffers a major heart attack, the damaged cardiac tissue doesn’t regenerate effectively, leading to a permanent loss of heart function. The tissue that was damaged doesn’t recover,” said MIT principal investigator Ana Jaklenec. “Our goal is to restore that function and help people regain a stronger, more resilient heart after a myocardial infarction.”

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