Researchers at the Massachusetts’ Worcester Polytechnic Institute have turned spinach leaves into human heart tissue, using the vein network in the spinach leaf to carry blood, similar to the blood vessel network in the heart. They stripped the spinach leaves of plant cells, replacing them with human heart tissue that beat for up to three weeks. >> Read more trending news “We have a lot more work to do, but so far this is very promising,” WPI biomedical engineering professor and study author Glenn Gaudette said in a press release on the study results. “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,” Gaudette added. The demand for healthy heart muscles for heart attack victims and for heart transplants cannot keep up with the supply. Almost 120,000 Americans are on the national transplant list, and 22 die every day waiting for an organ, according to government statistics. Every year, the number of people on the waiting list increases, as well. Scientists looked at current bioengineering techniques, including 3-D printing, as a possible solution for creating a new heart, for example, WPI officials said, but, they “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.” In addition to spinach, scientists are also studying other plants, like parsley and sweet wormwood, which they believe may also have medical value in tissue regeneration studies. The study was published in the journal Biomaterials.