A team of researchers from China and the U.S. has found that applying a specially designed microneedle patch to cardiac muscle damaged during a heart attack can promote the growth of myocytes.
In their paper published in the journal Science Advances, the group explains the mechanics of the patch and how well it worked when tested on animals.
During a heart attack, blood often stops flowing to certain parts of the cardiac muscle, leading to cell death and damage to the heart.
In most cases, such damage is permanent, leaving patients with reduced heart function.
In recent years, scientists have been trying to apply stem cells to damaged heart muscle to heal it—but such research has not progressed well.
The stem cells must be injected into the muscle, and they rarely take hold.
In this new effort, the researchers applied a microneedle patch to the damaged areas to introduce the stem cells and allow growth of heart muscle cells (myocytes).
The patch works by means of microchannels opened by the microneedles, which direct stem cells directly to heart cells and promote communication between the two.
The patch is a thin film and is called MN-CSC.
During testing, the team used patches that were 0.5-centimeter by 0.5-centimeter in size.
The new technique involves cutting open the heart to gain access to the damaged area. Next, a microneedle patch is applied directly to the damage.
The heart is then sewn back together and the patient allowed to recover.
The patch must be removed in a second operation.
The researchers have tested the patch on rats and pigs.
They report that it reduced cell death and also promoted the growth of myocytes, which led to the growth of new heart muscle tissue.
The researchers note that they did not encounter any unexpected side-effects—the patch is biocompatible and works as expected.
Before they move on to testing in humans, they plan to explore ways to apply a patch that do not involve open heart surgery, and to make the patch dissolvable.
More information: Junnan Tang et al. Cardiac cell–integrated microneedle patch for treating myocardial infarction, Science Advances (2018). DOI: 10.1126/sciadv.aat9365
Journal reference: Science Advances