Researchers at the Austrian Academy of Sciences have developed the most realistic cardiac organoids to date. The tiny structures self-organize from pluripotent stem cells to form an empty chamber that can beat. The method for creating “cardioids” involves stimulating various signaling pathways in stem cells and does not rely on conventional tissue engineering techniques, which typically use a scaffolding material as the basis for these structures. Consequently, the growth of the resulting tissue mimics the process of development in humans. Researchers hope organoids will provide more valuable data on heart disease and treatment.
Organoids are hugely valuable for modeling diseases and testing treatments. However, in some respects, this technology is still in its infancy. Researchers are still perfecting techniques for creating and using organoids in medical research. Many groups adopt a classical approach to tissue engineering when resembling organoids, which involves combining cells and a biomaterial scaffold. However, this is somewhat crude compared to the way organs develop in humans, which usually involves self-organization of cells.
“Self-organization is how nature causes snowflake crystals or birds to behave in a herd. This is difficult to figure out because there seems to be no plan, but something very tidy and robust still comes out, ”said Sasha Mendjan, a researcher involved in the study. “The self-organization of the organs is much more dynamic and there are many things we do not understand. We believe that this “hidden magic” of development, what we do not yet know, is the reason why diseases are not currently modeled very well. “
Mendjan and colleagues adopted a different approach and, instead of biomaterials, activated all known signaling pathways involved in cardiac differentiation and development in human pluripotent stem cells. There are six known signaling pathways and the team activated them in a particular sequence. This stimulated the cells to self-organize and grow in an empty chamber with different layers that demonstrated a beating movement, as did the developing heart.
“It’s not that we’re using anything different than other researchers, we’re just using all the known signals,” Mendjan said. “[Other researchers] He thought, “Okay, they’re not really needed in vitro.” But it turns out that all of these avenues are necessary. They are important for cells to self-organize in an organ.
Study the magazine Cell: Cardioids reveal principles of self-organization of human cardiogenesis