How scientists have printed a small heart from human cells

It has four chambers, blood vessels and it beats – somehow.

In a first, scientists printed a 3D heart using human tissue. Although the heart is much smaller than that of a human being (this is only the size of a rabbit) and there is still much to be done for that. It works as a normal heart, concept validation experience could eventually lead to the creation of custom organs or tissues. which could be used in the human body, according to a study published Monday, April 15 in the journal Advanced Science.

To print the heart, researchers at the Tel Aviv University in Israel began by taking a small sample of adipose tissue from a patient. In the laboratory, they separated this tissue into its constituent cells and the structure on which the cells rest, called the extracellular matrix. [7 Cool Uses of 3D Printing in Medicine]

By using genetic engineering, scientists then tweaked the different components, reprogramming certain cells to make them cells of the heart muscle, or cardiomyocytes, and some to generate blood vessels.

The researchers then loaded these cells – serving as "bio-links" – into the printer, which had been programmed to print a heart, based on tomodensitograms taken from the patient and a representation of the heart by the artist. It took between 3 and 4 hours for the printer to print the little heart with basic blood vessels. The researchers then incubated the heart and gave it oxygen and nutrients. In a few days, the cells began to beat spontaneously.

But that beat did not really look like what a healthy human heart would do. "We need cells to beat synchronously and not individually," said Assaf Shapira, co-author of the study, head of the laboratory's Laboratory of Tissue Engineering and Regenerative Medicine at the University. from Tel Aviv. In order for the heart to pump blood efficiently into the body, its cells must beat in unison – which the 3D printed heart has not yet done. "Right now, we are working on the maturation of the fabric," Shapira said.

Finally, a personalized 3D heart could alleviate the shortage of organs to transplant and could also avoid some of the risks associated with another person's organ transplant, namely that the immune system of the body Body can reject these foreign tissues, Shapira told Live. Science.

Camila Hochman Mendez, associate director of organ research laboratories, repair and regeneration at the Texas Heart Institute, which was not part of the study, said the new findings are "truly innovative and advance the field "by demonstrating that something more complex than a single wall of the heart can be printed. But the results "also show all the obstacles that the field is still facing," she added.

In order to print a normal sized and fully functioning heart, scientists should print a higher resolution organ – an organ endowed with a much larger vascular system and one that could carry oxygen and blood. nutrients Hochman Mendez told Live Science. But that would require months of printing – a period during which cells would not survive.

The researchers pointed out that the tiny heart remained a "proof of concept", but that they hoped to find a way to create a denser vascular system in the future.

"Of course, if we needed to make a bigger heart, it would be expensive, it would take a lot longer to print and a lot more material should be extracted from the patient," Shapira said.

Indeed, there is still a lot of research to be done before it becomes commonplace to simply hit "print" on the 3D printer at the doctor.

Originally published on Science live.