Have you ever looked at plant leaves and thought that their veins looks similar to our veins? Some scientists took that thought to its logical conclusion and used spinach and parsley leaves to bioengineer human veins.
Bioengineering may have come a long way since its inception, yet the task of creating veins and vascular networks is still beyond most scientists, especially since current methods of creating tissues cannot replicate the body’s smallest veins, which have at most a diameter of 10 micrometers (that’s 0.000001 meters). To solve this problem, a fairly large team of scientists from various universities recently developed a novel concept to create viable human veins: use spinach and parsley leaves as a scaffold. The researchers published their findings, titled “Crossing Kingdoms: Using Decellularized Plants as Perfusable Tissue Engineering Scaffolds,” in the journal Biomaterials.
One might wonder why the scientists chose plant leaves. According to the researchers, “Plants and animals exploit fundamentally different approaches to transporting fluids, chemicals, and macromolecules, yet there are surprising similarities in their vascular network structures. Plant vasculature follows Murray’s Law, which is the physiological law describing the tapered, branching network design of the human cardiovascular system.” Furthermore, plant vasculature contains cellulose, a material that is “biocompatible and has been shown to promote wound healing.”
The scientists started the study by decellularizing the leaves, i.e., separating the cellulose scaffolding from the rest of the cells that make up the leaves. The process turned the leaves translucent and ready to receive human cells. The leaves were then seeded with various cells, including umbilical cord vein cells and stem cells, which grew around the cellulose scaffolding.Once the bioengineered veins were finished growing, the scientists poured fluids filled with tiny objects known as microspheres into the veins to determine their diameters.
While the study was technically a success, it actually was a “proof of concept,” as the scientists admit they do not know how to integrate their bioengineered veins into the human vasculatory system. Furthermore, the scientists claim the immune system could negatively react to the bioengineered veins. Moreover, the detergents used to decellularize the plants are known ruin the viability of cells, which can be a problem when the detergents are used in high concentrations. However, if these issues can be addressed, the study stands a strong chance revolutionizing tissue grafting.
People who are interested in reading the study in its entirety can visit ScienceDirect. Word of warning: it is extremely technical.