A team of engineers from Massachusetts Institute of Technology (MIT)developed a flexible drug delivery patch that can be placed on the heart after a heart attack to help promote healing and regeneration of heart tissue.
The new device is designed to carry three different drugs that can be released at different times, according to a pre-established schedule. In experiments with rats, researchers showed that this treatment reduced the amount of damaged heart tissue by 50% and significantly improved heart function.
The details are published in the journal Cell Biomaterial And, according to scientists, if approved for use in humans, this type of engineering could help heart attack victims regain more heart function than is currently possible.
After a heart attack, many patients end up undergoing bypass surgery, which improves blood flow to the heart, but does not repair damaged heart tissue, details a statement from MIT. In the new study, the team wanted to create a patch that could be applied to the heart at the same time as surgery.
The researchers designed a three-drug regimen that promotes heart healing in different ways. And when the tissue regenerates, it follows a series of carefully synchronized steps, explains Ana Jaklenec.
The first set of particles releases neuregulin-1, a growth factor that helps prevent cell death.
In the next moment, the particles release VEGF, a growth factor that promotes the formation of blood vessels around the heart. The latest batch releases a small molecule drug called GW788388, which inhibits the formation of scar tissue that can occur after a heart attack.
For this study, The researchers created miniature compact patches just a few millimeters in diameter.
“We encapsulate sets of these particles in a hydrogel patch -similar to a contact lens-, which we then surgically implant in the heart. In this way we program the treatment in the material itself,” says Erika Wang.
They tested them on spheres of heart tissue, which they exposed to low-oxygen conditions, mimicking the effects of a heart attack, and then placed the patches on them. These promoted the growth of blood vessels, helped more cells survive, and reduced the amount of fibrosis that developed.
In tests with a rat model of myocardial infarction, they also observed significant improvements after treatment with the patch.
Compared with its absence or intravenous injection of the same drugs, animals with the patch showed a 33% higher survival rate and a 50% reduction in the amount of damaged tissue.
The team hopes to test them in other animal models in hopes of conducting a future clinical trial.