American researchers have successfully fabricated functional human heart tissue in a spinach leaf. The idea is to use the structure of the plant’s vessels to feed the cells of the heart with nutrients.
After a heart attack, the cells of the damaged no longer able to contract, resulting in a risk of heart failure. These cells would need to be replaced with a . Because of the lack of organ donors, scientists have set themselves the goal of recreating cardiac tissue in the laboratory by biological engineering. But it is not enough to get to get a simple pile of cells still need to supply them with . So how to artificially reconstruct a network of capillary vessels?
One solution may be to print the vessels in 3D. Here, a team of the Polytechnic Institute Worcester proposes to use… plants. Because despite their many differences, plants and animals have similarities in the structure of their vascular networks. The use of plants has advantages: the of plants is biocompatible, and inexpensive; The cultivation of plants also raises fewer ethical questions than laboratory animals.
For this study published in Biomaterials , researchers have simply bought spinach leaves from a local merchant. Then, they used a detergent solution to remove the plant cells: this “decellularization” step removes the cellular material while retaining an extracellular matrix . “I had done decellularization work on human hearts before, and when I looked at the spinach leaf its stem reminded me of an aorta,” said Joshua Gershlak, one of the authors of this work, in Science alert . Hence the idea of using the stem to pass the blood which will then be distributed in the tiny vessels of the leaf.
A decellularized tissue is interesting for a transplant : without donor cells, it should reduce the risk of rejection. The cells of the recipient can then repopulate the structure.
Green technology that regenerates vascular tissue
The decellularized plant tissue is then re-ligated with human endothelial cells, which colonize the internal surface of the vessels of the plant. Of stem cells human are used to provide cardiomyocytes that adhere to the outer surface of the plant matrix. In 21 days, the cardiac cells began to contract spontaneously as they would have done in human tissue.
There is still much work to be done to make this discovery applicable to humans, as the authors explain: “At present, it is not yet known how the vascular system of the plant would be integrated into the native human vascular system, There would be an immune response “. In addition, decellularization uses detergents that could remain as residues and impair the viability of the cells.
The team also tested other plants: leaves of parsley or roots of peanut . The spinach leaf was preferred because of the high density of its vessels. But the researchers suggest that in the future other plants are used to mimic different tissues: the hollow, cylindrical structure of a rod Impatiens capensis (Cape Impatience) could be used to make a graft to an artery ; The structure of the wood could be useful to make bone …
This is not the first time that scientists use plants as a support to grow human tissue. Last year, Canadian scientists grew a human ear on an apple slice.