They’re now using the method to model and study congenital heart disease. While they’re still perfecting the process, the researchers believe these human heart organoids could be used to study other cardiovascular conditions, like chemotherapy-induced cardiotoxicity and the effects of diabetes on the developing fetal heart.

“These minihearts constitute incredibly powerful models in which to study all kinds of cardiac disorders with a degree of precision unseen before,” said MSU professor Aitor Aguirre, the senior author on a paper detailing the research.

There’s a lot of interest in growing and printing human hearts. Researchers from Chicago to Tel Aviv have printed 3D hearts from patient-derived cells, and researchers in Japan have transplanted lab-grown heart tissue into a human heart.