WHY THIS MATTERS IN BRIEF
Four years ago we could “only” 3D print human heart tissue, now we have a working mini human heart, and by the end of this decade we could have a full sized version that could be transplanted into the first brave patients.
Although heart tissue has previously been 3D printed, in space no less, and elsewhere mini human hearts have been grown from stem cells in jars and in dishes, and researchers have even created synthetic heart cells to repair damaged hearts, scientists have now finally succeeded in creating the world’s first 3D Bio-printed vascularised heart from a patient’s own biological materials. And it’s a stunning science fiction-like accomplishment – especially given the fact that 3D bio-printing itself has only really been around for five years or so, and one that will pave the way for custom made-to-order replacement human organs in the years and decades to come.
Led by Prof. Tal Dvir the team at Israel’s Tel Aviv University started by taking a fat sample from a volunteer. That fat was then separated into its cellular and non-cellular materials. The cells were subsequently programmed to become pluripotent stem cells, which are capable of differentiating into any type of body cell. Meanwhile, the extracellular matrix, the non-cellular material, which consists largely of collagen and glycoproteins, was then made into a hydrogel.
See how the breakthrough was accomplished
Next, the stem cells were mixed into batches of the gel, after which they were prompted to differentiate into either cardiac or endothelial cells, the latter being cells that line the interior surface of blood vessels. This resulted in two types of bio-ink that were then extruded from the nozzle of a 3D bio-printer and into an Alginate-Xanthan gum supporting medium. Building up biological tissue layer by layer, this approach was first used to make patches of cardiac tissue, after which the complete heart was made.
Although the bio-printed organ is only about the size of a rabbit heart, it has all the same chambers and blood vessels as a full-size human heart, which Dvir says could be created utilising the same process. Because such organs would be made from the patient’s own biological materials, rejection by the immune system shouldn’t be a problem. Additionally, and very importantly, patients wouldn’t need to wait for donor hearts to become available, and that’s a game changer that would save potentially millions of lives. Before that point is reached, however, more work needs to be done.
“We need to develop the printed heart further,” says Dvir. “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 10 years, there will be organ printers in the finest hospitals around the world, and these procedures will be conducted routinely.”
A paper on the research was published in the journal Advanced Science.