Growing human hearts: The answer is spinach leaves?

We could someday be using spinach to grow human hearts, thanks to new research from the Worcester Polytechnic Institute, the University of Wisconsin-Madison and Arkansas State University.

One of the problems that researchers have faced is how to create a vascular system that can deliver blood deep into developing tissues. There hasn’t been much success with 3D printing vascular networks to provide the transportation for oxygen, nutrients and other essential molecules that allow for continued tissue growth.

Even though plants and animals transport fluids differently, they have similar vascular structures.

The research team stripped the plant cells from spinach leaves and pushed fluids and microbes that were similar to the size of human blood cells through the remaining vascular network of the spinach leaves. The spinach veins were then seeded with human cells that come from blood vessels. This allows for the leaves to grow healthy heart muscles that can help treat heart attack patients.

“We have a lot more work to do, but so far this is very promising,” Glenn Gaudette, PhD, professor of biomedical engineering at Worcester Polytechnic Institute and corresponding author on this study, said in a news release. “Adapting abundant plants that farmers have been cultivating for thousands of years for use in tissue engineering could solve a host of problems limiting the field.”

Joshua Gershlak, a graduate student in Gaudette’s lab and first author on the study, perfused a detergent solution through the spinach leaves’ veins to remove the plant cells.

“I had done decellularization work on human hearts before,” Gershlak said. “And when I looked at the spinach leaf, it’s stem reminded me of an aorta. So I thought, let’s perfuse right through the stem. We weren’t sure it would work, but it turned out to be pretty easy and replicable. It’s working in many other plants.”

Once the plant cells were washed away all that was left of the vascular system was made from cellulose, which is a naturally forming substance that poses no harm to people.

Cellulose is biocompatible and can be used in regenerative medicine like engineering cartilage tissue, bone tissue and wound healing, according to the authors of the study.

The research team has also been able to remove plant cells from parsley, sweet wormwood and peanut hairy roots and hopes these different plants could help with other specialized tissue regeneration studies.

Spinach leaves are better for highly vascularized tissues like the heart. The structure of jewelweed is better for arterial grafts. Wood could be better used in bone engineering because of its strength and geometries, according to the study.

Using plants to grow tissue is economically and environmentally-friendly because the plants can be grown with proper agricultural techniques, reducing the need for costly synthetic and complex composite materials.

This research adds on to the other cardiology advancements and innovations that have recently come to light, including growing heart cells from stem cells.

The study was published online in the Biomaterials journal.

[Want to stay more on top of MDO content? Subscribe to our weekly e-newsletter.]