The first heart in the world printed in 3D with human tissue revealed

Scientists have called a "major medical breakthrough" a 3D printed heart with human tissues and vessels.

The heart, which is about the size of a rabbit, advance the possibilities of transplants, according to the researchers.

Developed at Tel Aviv University in Israel, the project team says it's a world first.

Tal Dvir, who led the project, said it was "the first time anyone has designed and successfully printed an entire heart filled with cells, blood vessels, ventricles and chambers".

"People have managed to 3D print the structure of a heart in the past, but not with cells or blood vessels," he said.

Scientists hope one day to be able to produce hearts suitable for transplantation in humans as well as patches to regenerate defective hearts.

The results were published in the Advanced Science peer-reviewed journal.

Challenges ahead

The cells can contract, but the researchers must teach them how to pump. Then they plan to transplant them into animal models in about a year, Dvir said.

Another problem is how to develop cells to have enough tissue to recreate a human-sized heart, he said.

The current 3D printers are also limited by the size of their resolution and another challenge will be to understand how to print all the small blood vessels.

According to the World Health Organization, cardiovascular disease is the leading cause of death in the world and grafts are currently the only option available to patients in the most severe cases.

But the number of donors is limited and many people die while waiting – or sometimes the body of patients rejects the transplant.

Researchers are working to overcome this problem by performing a biopsy of patients' fat tissue that has been used in the development of "ink" for 3D printing.

First, patient-specific heart patches were created, followed by the entire heart, the statement said.

Using the patient's own tissue was important to eliminate the risk that an implant will cause an immune response and be rejected, Dvir said.

"The biocompatibility of engineering materials is crucial to eliminate the risk of rejection of implants, which compromises the success of such treatments," said Dvir.