Researchers face a fundamental challenge as they seek to scale up human tissue regeneration from small lab samples to full-size tissues, bones, even whole organs to implant in people to treat disease or traumatic injuries: how to establish a vascular system that delivers blood deep into the developing tissue.
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. To solve this problem, a multidisciplinary research team at Worcester Polytechnic Institute (WPI), the University of Wisconsin-Madison, and Arkansas State University-Jonesboro have successfully turned to plants. They report their initial findings in the paper “Crossing kingdoms: Using decellularized plants as perfusable tissue engineering scaffolds” published online in advance of the May 2017 issue of the journal Biomaterials.
Plants and animals exploit fundamentally different approaches to transporting fluids, chemicals, and macromolecules, yet there are surprising similarities in their vascular network structures,” the authors wrote. “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.”
In a series of experiments, the team cultured beating human heart cells on spinach leaves that were stripped of plant cells. They flowed fluids and microbeads similar in size to human blood cells through the spinach vasculature, and they seeded the spinach veins with human cells that line blood vessels. These proof-of-concept studies open the door to using multiple spinach leaves to grow layers of healthy heart muscle to treat heart attack patients.