Engineers at MIT have developed a flexible drug-delivery patch that can be attached to the heart following a heart attack to promote tissue healing and regeneration. The innovative patch is designed to carry multiple therapeutic agents and release them according to a pre-programmed schedule.
In a study conducted on rats, this treatment reduced the amount of damaged heart tissue by 50% and significantly improved cardiac function. If approved for human use, this technology could help heart attack patients recover more cardiac function than currently possible.
Programmed Drug Delivery System
The research team, led by senior authors Jaklenec and Institute Professor Robert Langer of MIT’s David H. Koch Institute, built upon their previous work with drug-carrying microparticles. These tiny capsules, resembling miniature covered coffee cups, are made from a polymer called PLGA that can be sealed with medication inside.
By adjusting the molecular weight of the polymer used for the “lids,” the researchers can control degradation rates, enabling programmed release at specific intervals. For this application, they engineered particles to release their contents at three critical phases: days 1-3, 7-9, and 12-14 post-implantation.
Multi-Stage Therapeutic Strategy
The timed release strategy addresses different aspects of cardiac repair:
- Phase 1 (days 1-3):Neuregulin-1, a growth factor that helps prevent cell death
- Phase 2 (days 7-9):VEGF, a growth factor promoting blood vessel formation around the heart
- Phase 3 (days 12-14):GW788388, a small molecule drug that inhibits scar tissue formation
“This approach mirrors the body’s natural healing sequence by delivering key components at precisely the right time,” explained lead author Dr. Erika Wang, a former MIT postdoc.
Patch Design and Implementation
The researchers embedded rows of these programmed particles into a tough yet flexible hydrogel sheet made from alginate and PEGDA, biocompatible polymers that eventually break down in the body.
The resulting patch, only millimeters wide, can be surgically attached to the heart during open-heart procedures that many heart attack patients already undergo. “We’re essentially programming the treatment regimen directly into the material,” Wang added.
Experimental Validation and Results
Testing on human heart tissue spheroids containing cardiomyocytes, endothelial cells, and cardiac fibroblasts demonstrated that the patches promoted blood vessel growth, increased cell survival, and reduced fibrosis under oxygen-deprived conditions mimicking heart attacks.
In rat models of myocardial infarction, patch-treated animals showed a 33% improvement in survival rates, 50% less damaged tissue, and significantly enhanced cardiac output compared to untreated controls or those receiving intravenous drugs.
Future Directions and Clinical Translation
The patches safely dissolve over time, becoming an ultrathin layer within one year without disrupting cardiac mechanical function. While the current version requires surgical implantation, the team is exploring incorporating the microparticles into stents that could be inserted into arteries for minimally invasive drug delivery.
The researchers plan to test the patch in additional animal models with the goal of future clinical trials. This programmable drug delivery platform may also have applications beyond cardiac care for other organs requiring timed therapeutic interventions.
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