March 27, 2017
Scientists convert a spinach leaf into human heart tissue
Typically, when medical experts say that spinach is good for your heart, they mean that eating the leafy greens can lower your risk of cardiovascular disease, but researchers from Worcester Polytechnic Institute (WPI) in Massachusetts have taken things in a different direction.
In a study currently available online and scheduled to appear in the May print edition of the journal Biomaterials, WPI graduate student Joshua Gershlak and his colleagues revealed that they were able to build a working human heart muscle using a spinach leaf-like scaffolding.They decellularized the tissue of the spinach leaf, isolating its extracellular matrix (ECM), and then recellularized the resulting scaffold with human endothelial cells. These cells colonized the inner surfaces of the plant tissue, and eventually, stem cells and cardiomyocytes (cardiac muscle cells) began to attach to the scaffolding’s outer surfaces.
While, as National Geographic pointed out, scientists have already devised a way to create large-scale human tissue in the laboratory using 3D printing, thus far such technology has been unable to successfully reproduce the tiny, fragile blood vessels essential to the health of such tissue.
“The main limiting factor for tissue engineering... is the lack of a vascular network. Without that vascular network, you get a lot of tissue death,” Gershlak said in a video describing the research. His team’s work, Nat Geo explained, used the branching network of veins inherent in the leaf to replicate the way that blood travels through that vascular network in human tissue.
So how on Earth is this even possible?
This breakthrough could potentially provide a new, better way to repair damaged organs, not to mention make tissue engineering better by providing a new way for scientists to grow a vascular system. But, you may be wondering, how is it even possible to turn spinach into heart muscle?
The key, the study authors explained, is in the fact that removing the plant cells from a spinach leaf leaves behind a framework made of cellulose, a biocompatible material which is often used in regenerative medicine to engineer bone tissue or cartilage. Once the human cells were added to the framework, this allowed them to grow and surround the leaf’s network of veins.
After the transformation was complete, the researchers send fluids and microbeads through the vascular network, successfully demonstrating that the system was capable of transporting white and red blood cells, Nat Geo said. While Gershlak’s team cautioned that their research is still in the early stages, they remain optimistic about its potential.
“We have a lot more work to do, but so far this is very promising,” corresponding author Dr. Glenn Gaudette, a professor of biomedical engineering at WPI, 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.”
“By exploiting the benign chemistry of plant tissue scaffolds, we could address the many limitations and high costs of synthetic, complex composite materials,” the researchers wrote in their study. “Plants can be easily grown using good agricultural practices and under controlled environments. By combining environmentally friendly plant tissue with perfusion-based decellularization, we have shown that there can be a sustainable solution for pre-vascularized tissue engineering scaffolds.”
Image credit: Worchester Polytechnic Institute