The process of printing the heart involved a biopsy of the fatty tissue that surrounds abdominal organs. Researchers separated the cells in the tissue from the rest of the contents, namely the extracellular matrix linking the cells. The cells were reprogrammed to become stem cells with the ability to differentiate into heart cells; the matrix was processed into a personalized hydrogel that served as the printing “ink.”
The cells and hydrogel were first used to create heart patches with blood vessels and, from there, an entire heart.
“At this stage, our 3D heart is small, the size of a rabbit’s heart,” Dvir said. “But larger human hearts require the same technology.”
Previously, scientists had been able to print only simple tissues without blood vessels.
Dvir also explained that using the patient’s own cells is key to engineering the tissues and organs.
“The biocompatibility of engineered materials is crucial to eliminating the risk of implant rejection, which jeopardizes the success of such treatments,” he said.
Next, the researchers plan to train the hearts to behave like hearts, Dvir explained. “The cells need to form a pumping ability; they can currently contract, but we need them to work together.”
If researchers are successful, they plan to transplant the 3D-printed heart in animal models and, after that, humans.
“Maybe, in ten years, there will be organ printers in the finest hospitals around the world, and these procedures will be conducted routinely,” Dvir said.