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Beating cardiac tissue has been created in the lab from human embryonic stem cells by researchers at the Technion-Israel Institute of Technology's biomedical engineering faculty and the Rappaport Medical Faculty. In addition, researchers Dr. Shulamit Levenberg and Prof. Lior Gepstein also managed to bring about the creation of tiny blood vessels within the tissue, which makes possible their tissue's implantation in a human heart.
With help from doctoral student Oren Caspi and master's degree student Ayelet Lassman, the Technion researchers said that without the new blood vessels, the tissue would be likely to die quickly. "In our work," said Levenberg, "we showed the importance of endothelial cells (from which coronary vessels are composed) that induce the differentiation of stem cells into heart cells and their organization as tissue and encourage their multiplication. That is, it's important to create cardiac tissue with all the cells that compose them. In this case, it is endothelial cells, cardiac cells and cells that support blood vessels."
The researchers, whose study appears in the on-line edition of the prestigious journal Circulation Research, created the heart tissue in their lab by sorting human embryonic stem cells that turned into heart muscle cells and growing them together with endothelial cells and embryonic fibroplasts. The culture was carried out in three dimensions on a scaffold made of self-destructing sponge material that the researchers also created in their lab. In the future, they will look into the possibility of implanting the engineered cardiac tissue, with the blood vessels improving the implantation of the new tissue and its connection to the blood system.
The technique is aimed eventually at helping patients who have cardiac insufficiency due to heart attacks.
Levenberg, a 38-year-old modern Orthodox mother of five including a baby, has devoted her professional career to cutting-edge tissue engineering research that she hopes will eventually lead to the creation of lab-manufactured tissues and organs for transplants and the curing of degenerative diseases. She earned her bachelor's degree in biology at the Hebrew University of Jerusalem and her Ph.D. at the Weizmann Institute of Science in Rehovot, after which she went for a five years of post-doctoral work at the Massachusetts Institute of Technology, where she built biological scaffolds to coax stem cells into developing into specific cell types.