In recent months, scientists have been making rapid progress in regenerative medicine, using cutting-edge tissue engineering techniques to restore liver function in mice, regrow human muscle, and even implant bioengineered blood vessels into sick patients. And now, some researchers have succeeded in growing human heart tissue that can beat autonomously in a petri dish, a significant step toward developing transplantable replacement organs.

Cardiovascular diseases are a significant global health issue. Cardiovascular disease (CVD) is the leading cause of death in developed countries, accounting for one-third of all deaths in the US alone. Congenital heart defects (CHD) affect less than 1% of newborns, making them the most common congenital disability in humans.

The study of cardiovascular disorders is a common problem for scientists, but now a team of researchers has successfully created a miniature human heart model in the laboratory. To be more precise, they have regrown an existing donor heart, using stem cells to replace any cells that might cause the recipient to reject it. This could pave the way for completely lab-grown custom organ replacements that are completely compatible with the done.

For the first time in history, this model is complete with all primary heart cell types and a functioning structure of chambers and vascular tissue. The researchers believe that their model will allow them to study all types of cardiac disorders more accurately than previously. 

This isn’t the first time scientists have successfully engineered heart tissue; in recent years, other groups have created lab-grown beating rat hearts and even human heart tissue. The latter breakthrough, on the other hand, relied on embryonic stem cells, which cannot be derived from a specific patient for subsequent, personalized transplantation in the same way that this new technique allows.

Of course, a full-sized, fully functional replacement human heart is still several years away. However, scientists hope that in the near future, they will be able to create personalized “patches” of the human heart muscle to repair damaged organs and that their technique will be used to more accurately study the effects of new pharmaceuticals to treat cardiovascular ailments.

Over the course of several weeks, the transplanted human cells proliferate and differentiate, transforming the scaffold into a functioning organ capable of beating on its own. Right now, the heart tissue contracts at a rate of 40 to 50 beats per minute (about the same as a human’s resting heart rate), but it needs to be refined further before it can beat strongly enough to distribute blood or speed up.

The study is only the first of many experiments that the research team will conduct. Their model, while complex, is far from perfect. The team intends to improve the organoid in order to provide a more suitable version for future research and use.

According to the team, the mini heart is not as perfect as the human heart, but they are working on it. The team also hopes that the miniature hearts will have a broad range of applications, allowing them to study other cardiovascular-related diseases such as chemotherapy-induced cardiotoxicity and the effects of diabetes on the developing fetal heart during pregnancy.