Researchers have developed a 3-D printed patch that can deliver healthy cells to the heart after a heart attack.
During an acute myocardial infarction, or heart attack, the blood vessels feeding the heart are blocked, impeding the flow of oxygen-rich blood to the organ. Because of this, nearly half of the heart’s cells drastically weaken the heart and its ability to function, increasing the risk of disease and death. But researchers from the University Medical Center Utrecht (UMCU) have now developed a 3-D printed patch that can help deliver healthy cells to the heart after a heart attack, helping to repair the damaged tissue and prevent further problems.
Miguel Dias Castilho, a professor of biofabrication at UMCU, says that the use of 3-D printing, specifically an electrohydrodynamic technique called melt-electrowriting (MEW), allowed him and his colleagues to control the spatial deposition of materials as they fabricated a unique hexagonal patch structure.
“This allowed us better control over the creation of gradients within the scaffold, such as mechanical, and the growth factor of cells, which is not possible with conventional injection mold approaches,” he said. “MEW permitted us to print with incredible high precision fiber networks so we can tailor the design to have unique flexibility and shape-recovery properties, meaning the patch can be deformed without sustaining damage to the structure or cells within it.”
The patch is made up of three main components: the 3-D printed hexagonal backbone, a collagen-based hydrogel, and induced pluripotent stem cells cardiomyocytes (iPSC-CMs).
“We grow the cells in the lab and then combine them with the patch where they continue to mature,” Castilho said. “The scaffold, together with the hydrogel, creates an optimal 3-D environment for cell growth.”
When the patch is placed on a contracting heart, during both in vitro testing or surgically in a large in vivo animal model, the design is strong enough to handle the tensile strain, while keeping the necessary cells in place. The results were published in Advanced Functional Materials.
“The engineering microenvironment allowed for a better recapitulation of the anisotropic mechanical response of native myocardium,” said Castilho. “We also observed that, even in the absence of external stimuli, the human iPSC-CMs were guided to the right place.”
While Castilho is excited about these results, he said, but much more needs to be done before the patch can be used for clinical applications.
“This is an important achievement, but there is still work to do to drive the cells towards maturity,” he said. “Our final aim is to use these cardiac patches as support for cardiac function in patients with end-stage heart failure. For the immediate future, we want to concentrate our efforts in conducing more extensive animal studies to assess feasibility and such functional effects, such as improved cardiac function.”
In the future, Castilho hopes to make more complex patches that are better integrated with native tissue and can contain more cell types. He also wants to create similar MEW-fabricated patches that could be used in hernia or prolapse repair, replacing the meshes that are currently used. With all that, he remains most excited about its possibilities in cardiac repair.
“This patch is highly flexible, yet very robust. We have developed a minimally invasive delivery technique, where we inject it through a catheter-like tubing, as many cardiac patients cannot undergo invasive surgery,” he said. “We believe this patch would be a strong step forward for current clinical and commercial options to help repair heart damage.”
Kayt Sukel is an independent writer focusing on technology.