We’ve become wary of headlines that read “Scientists 3D print human heart!” And with good reason. Still, there is sometimes something behind the headline that is of interest. In this case, a team of researchers from Tel Aviv University have 3D printed a small-scale heart that integrates vascularization, ventricles and chambers and is made from a patient’s cells.
The achievement is significant, as it marks the first time that such a complex 3D printed heart has been engineered and produced. In fact, it is reportedly the world’s first 3D vascularized engineered heart made from a patient’s cells and biological materials.
The research study, recently published in the journal Advanced Sciences, showcases the potential of this particular 3D printing technique for engineering patient-specific tissues and organs or for patient-specific drug screening applications.
Led by Prof. Tal Dvir, the research culminated in the 3D printing of a small heart—about the size of a rabbit’s heart—whose materials were derived from a biopsy of fatty tissue taken from a patient. The sample tissue was separated into cellular and a-cellular materials, and the resulting cells were reprogrammed as pluripotent stem cells.
To enable the 3D printing, an extracellular matrix—a network of extracellular macromolecules such as collagen and glycoproteins—was made into a custom hydrogel in which the stem cells could be integrated. Once mixed with the hydrogel, the cells were differentiated into cardiac or endothelial cells. A bioprinter was then used to deposit layers of the hydrogel to produce immune-compatible cardiac patches with blood vessels and eventually an entire heart structure.
“This heart is made from human cells and patient-specific biological materials,” said Prof. Dvir. “In our process these materials serve as the bioinks, substances made of sugars and proteins that can be used for 3D printing of complex tissue models. 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.”
By using the patient’s own cells for bioprinted structures, there is less of a risk of implants being rejected by the body. In the future, 3D bioprinted organs could serve as safer alternatives for implantation than transplants from other patients because of their customizability.
“The biocompatibility of engineered materials is crucial to eliminating the risk of implant rejection, which jeopardizes the success of such treatments,” Prof. Dvir explained. “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, vascularized and perfusable cardiac tissues that completely match the immunological, cellular, biochemical and anatomical properties of the patient.”
The next step in the breakthrough research project will be to culture the 3D printed hearts in a laboratory environment and program them to function like real hearts, with pumping capabilities. Once the culturing is complete, the scientists will move ahead into animal testing.
“We need to develop the printed heart further,” Prof. Dvir concluded. “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.”
Though the project’s innovation should not be discounted—as it could prove to be an important step in the development of 3D printed implantable organs—it should be stated that the medical world is still about a decade away from seeing any viable 3D bioprinted implants.