Scientists Used Human Tissue to 3-D Print a Tiny Heart

Researchers have successfully 3-D printed a miniature heart complete with cells, blood vessels, ventricles and chambers. The engineered organ—crafted using “ink” made from the patient’s cells and biological materials, according to Bloomberg’s Michael Arnold—marks the first time scientists have moved beyond printing simple tissues lacking blood vessels.

The impressive prototype, newly described in Advanced Science, is roughly the size of a rabbit’s heart. Still, lead author Tal Dvir of Tel Aviv University explains in a statement, “larger human hearts require the same technology,” raising hopes that the technique can eventually be adapted to create functional heart patches or even power full organ transplants.

As Live Science’s Yasemin Saplakoglu reports, Israeli researchers built the grape-sized heart by extracting a fatty tissue sample from a patient and then separating this tissue into its component cells. After tweaking the cells’ function using genetic engineering and turning the non-cellular materials into a bio-ink gel, the team transferred them to a 3-D printer programmed to print a heart modeled on CT scans and an artist’s rendering. Three to four hours later, the tiny heart was ready—albeit still not functional.

Before coaxing the organ to “life,” or some semblance of it, Arnold notes that the scientists will need to wait about a month for the cells to mature. Currently, Delphine Matthieussent reports for Agence France-Presse, the cells can contract, but they lack the ability to pump. According to Saplakoglu, the heart’s cells must “beat in unison” in order to pump blood efficiently throughout the body. Once this feat is accomplished, Dvir tells AFP, the team hopes to transplant 3-D printed hearts into animal subjects.

The technology is still far from ready for testing in humans, but as study co-author Assaf Shapira, also of Tel Aviv University, tells Live Science, 3-D printed hearts could one day help supplement the low number of donor organs available for transplant. Given the fact that such manufactured organs would be personalized to each patient, the process would avoid risks associated with the immune system’s rejection of transplanted foreign tissue.

Heart disease is the leading cause of death in the United States, claiming the lives of more than 600,000 men and women every year. Oftentimes, Aristos Georgiou reports for Newsweek, the only treatment for advanced cardiac failure is a heart transplant. Unfortunately, heart donors—and organ donors in general—are in short supply.

This is where regenerative medicine comes into play: As the statement outlines, “Patients will no longer have to wait for transplants or take medications to prevent their rejection. Instead, the needed organs will be printed, fully personalized for every patient.”

Before this vision can become reality, however, scientists will need to figure out how to print a full-size, functioning heart—a daunting question considering the fact that such an operation would require “billions of cells,” according to Bloomberg’s Arnold, as opposed to the mini-heart’s comparatively paltry millions. Additionally, Camila Hochman Mendez, a researcher at Texas Heart Institute who was not involved in the study, tells Live Science’s Saplakoglu, printing a higher-resolution organ capable of carrying enough oxygen and nutrients to support a human body would take months, spanning a lengthy period of time the cells would likely not be able to survive.

The University of Sheffield’s Sam Pashneh-Tala, an expert who was also not involved in the new research, characterizes the heart as a “showpiece” in an interview with Newsweek’s Georgiou.

“This construct did not demonstrate any function as a heart,” Pashneh-Tala says. “... The approaches outlined are certainly exciting, but the study itself highlights that several challenges remain before a 3-D printed heart could be a viable clinical option for the treatment of organ failure.”

Dvir is more optimistic about the team’s findings. Although he acknowledges the need to “develop the printed heart further,” he concludes, “Maybe, in ten years, there will be organ printers in the finest hospitals around the world, and these procedures will be conducted routinely.”

Meilan Solly | | READ MORE

Meilan Solly is Smithsonian magazine's senior associate digital editor, history.