The team of scientists from Tel Aviv University printed the tiny heart complete with vessels, collagen, and biological molecules.
Using genetic engineering, the scientists then tweaked the various components, reprogramming some of the cells to become cardiac muscle cells, or cardiomyocytes, and some to become cells that generate blood vessels. This development is expected to be a "major medical breakthrough" for heart patients in the future. Many patients' bodies reject the transplant, leaving them with life-threatening consequences.
To print the heart, scientists used fatty tissue from patients.
"It was expected for a while that in a few years we will be able to 3D-print fully functional human hearts, which can replace our faulty ones", Radacsi told Newsweek.
The research team notes that one advantage of the printed organs is that there would be a lower organ rejection rates as the organs would be generated using the patient's own cells. The heart's cells can contract but not pump like a human heart does.
To demonstrate how the personalised hydrogel can be shaped into accurate, high resolution thick structures, researchers 3D-printed a human hand (this did not include the internal parts such as bone and blood vessels).
But he said hospitals would likely start with simpler organs than hearts.
It is pretty easy to imagine the printing of a 3d wood model, but how to go about printing a fleshy organ like a heart?
"The biocompatibility of engineered materials is crucial to eliminating the risk of implant rejection, which jeopardizes the success of such treatments", Professor Dvir said.
Norbert Radacsi, a chemical engineering lecturer at the University of Edinburgh in the United Kingdom, who was not involved in the latest research, described the development as an "amazing breakthrough", but noted that there are still several issues to be addressed.
"The cells need to form a pumping ability; they can now contract, but we need them to work together". Though the heart is much smaller than a human's (it's only the size of a rabbit's), and there's still a long way to go until it functions like a normal heart, the proof-of-concept experiment could eventually lead to personalized organs or tissues that could be used in the human body, according to a study published Monday (April 15) in the journal Advanced Science.
The Centers for Disease Control and Prevention positions the heart disorder as the main cause related to death in the US.
However, the printed vascularised and engineered heart is approximately 100 times smaller than a real human heart.
And that is still good news that offer a sliver of hope to the patients, considering that heart transplants are the only option for the people who live with heart and circulatory diseases, many of which will die while their names are still on the waiting list.