In a major medical breakthrough, researchers at the
University of Tel Aviv have “printed” the world’s first 3D
vascularised engineered heart using a patient’s own cells and biological
materials. Their findings were published today (15 April) in a study in Advanced
Science.

Until now, scientists in regenerative medicine have been
successful in printing only simple tissues without blood vessels.

“This is the first time anyone anywhere has
successfully engineered and printed an entire heart replete with cells, blood
vessels, ventricles and chambers,” says Prof Tal Dvir of
TAU’s School of Molecular Cell Biology and Biotechnology, Department
of Materials Science and Engineering, Center for Nanoscience and
Nanotechnology and Sagol Center for Regenerative Biotechnology, who
led the research for the study.

“This heart is made from human cells and
patient-specific biological materials. In our process these materials serve as
the bio-inks, substances made of sugars and proteins that can be used for 3D
printing of complex tissue models,” Prof Dvir says. “People have
managed to 3D-print the structure of a heart in the past, but not with cells or
with blood vessels. Our results demonstrate the potential of our approach for
engineering personalized tissue and organ replacement in the future.”

“At this stage, our 3D heart is small, the size of a
rabbit’s heart,” explains Prof Dvir. “But larger human hearts require
the same technology.”

For the research, a biopsy of fatty tissue was taken from
patients. The cellular and a-cellular materials of the tissue were then
separated. While the cells were reprogrammed to become pluripotent stem cells,
the extracellular matrix (ECM), a three-dimensional network of extracellular
macromolecules such as collagen and glycoproteins, were processed into a
personalised hydrogel that served as the printing “ink.”

After being mixed with the hydrogel, the cells were
efficiently differentiated to cardiac or endothelial cells to create
patient-specific, immune-compatible cardiac patches with blood vessels and,
subsequently, an entire heart.

According to Prof Dvir, the use of “native”
patient-specific materials is crucial to successfully engineering tissues and
organs.

“The biocompatibility of engineered materials is
crucial to eliminating the risk of implant rejection, which jeopardises the
success of such treatments,” Prof Dvir says. “Ideally, the
biomaterial should possess the same biochemical, mechanical and topographical
properties of the patient’s own tissues. Here, we can report a simple approach
to 3D-printed thick, vascularised and perfusable cardiac tissues that
completely match the immunological, cellular, biochemical and anatomical
properties of the patient.”

The researchers are now planning on culturing the printed
hearts in the lab and “teaching them to behave” like hearts, Prof
Dvir says. They then plan to transplant the 3D-printed heart in animal models.

“We need to develop the printed heart further,” he
concludes. “The cells need to form a pumping ability; they can currently
contract, but we need them to work together. Our hope is that we will succeed
and prove our method’s efficacy and usefulness.

“Maybe, in ten years, there will be organ printers in
the finest hospitals around the world, and these procedures will be conducted
routinely.”

Source: https://www.aftau.org/weblog-medicine–health?&storyid4704=2446&ncs4704=3