Scientists Use Spinach Leaves to Make Human Heart Tissue

It looks like spinach is more than just good for you to eat – it could be an asset to human tissue and organ regeneration.

Researchers from the Worcester Polytechnic Institute, the University of Wisconsin–Madison and Arkansas State University–Jonesboro placed human heart cells onto spinach leaves stripped of plant cells – effectively creating working human heart tissue.

Study author Joshua Gershlak told The Washington Post they removed these plant cells by using soaps, leaving "behind the protein matrix and structure." The scientists then seeded the remaining spinach leaf veins with human cardiac muscle cells, which started to beat on their own five days later. Gershlak's team suspected this could work since cellulose is "a plant material known to be compatible with mammalian tissue," according to the Post.

Why spinach in particular? The plant's vascular structure attracted the scientists with its complexity, similar to human cardiac tissue. While plants and animals transport fluids, chemicals and molecules differently, according to the study authors, "the development of decellularized plants for scaffolding opens up the potential for a new branch of science that investigates the mimicry between plant and animal."

Scientists have faced issues when it comes to developing tissue through methods like 3-D printing; "a perfect heart" has yet to be printed, the Washington Post reports. "Current bioengineering techniques, including 3-D printing, can't fabricate the branching network of blood vessels down to the capillary scale that are required to deliver the oxygen, nutrients and essential molecules required for proper tissue growth," explains a Worcester Polytechnic Institute press release on the findings, which were published in the journal Biomaterials.

So what does this latest discovery mean for the future?

"We have a lot more work to do, but so far this is very promising," Glenn Gaudette, study author and professor of biomedical engineering at the Worcester Polytechnic Institute, said in a statement.

"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." Research will continue at the Worcester Polytechnic Institute, including projects exploring the cell removal process and how human cells function in plant-based scaffolds.

Gaudette also told The Washington Post, "Long term, we're definitely envisioning implanting a graft in damaged heart tissue," he said. The results could mean heart attack patients, for example, someday receive healthy heart muscle grown on spinach leaves.

And spinach isn't the only plant with such transformative potential. Researchers also conducted proof-of-concept studies in parsley, sweet wormwood and peanut hairy roots, showing the items' plant cells could be effectively stripped for potential infusion with human cells. Other plant species could lead to regeneration studies for different types of tissue.