In 2019, Israel produced a tiny heart, just about big enough to fit a rabbit. Submerged in a small cube of liquid to sustain it, the heart wasn’t able to pump blood—in fact, the cherry-sized, anatomically correct heart couldn’t function like a real heart at all, but its remarkable potential made it a historic invention despite its inability to function.
This was the first 3D-printed human heart. Although the technology is still in its infancy, scientists have discovered the key to making transplantable printed organs: bioink, made up of fatty tissue from a donor mixed with collagen and proteins. The heart had the same tissue layers as a human heart, including an intricate network of miniscule blood vessels scaled to size. Scientists have been working on engineering working organs for years, from kidneys to livers to corneas, and the success of the first heart—an incredibly difficult organ to recreate—is a massive step for medicine.
Doctors have been using bioprinting to create skin, cartilage, bladdars and muscle tissues since 1999, but this development has massive implications for the 102,000 Americans on the waiting list for an organ transplant in 2021.
