The heart was printed with patient-derived cardiac muscle cells, or cardiomyocytes, and bioink made from extracellular matrix compounds that replicate the properties of the mammalian heart. BIOLIFE4D first bioprinted human cardiac tissue in June 2018. Earlier this year, the company bioprinted individual heart components, including valves, ventricles and blood vessels. Its process involves reprogramming a patient's white blood cells into induced pluripotent stem cells (iPS cells), which can differentiate into different types of cells, including cardiac cells.

Eventually, the company hopes to bioprint a full-sized functioning human heart. Theoretically, bioprinted hearts could reduce or eliminate the need for donor organs. Of course, BIOLIFE4D isn't the only company looking to 3D print organs. Researchers at Tel Aviv University 3D printed a heart earlier this year. We've seen functioning 3D-printed silicone hearts, and bioengineers at MIT managed to 3D print complex vascular networks, like those necessary to sustain artificial organs.