The Path to Printed Body Parts

For patients in need of an organ transplant, the odds are bleak. Only around 30,000 people got transplants in the U.S. last year, while more than 8,000 died waiting, according to the United Network for Organ Sharing. In the U.S., 120,000 people are on the waitlist for organs; China’s list contains 1.5 million names. The World Health Organization estimates that the black market created by this soaring demand results in 10,000 illegal transplants each year. What if doctors could order an inexpensive, custom-made liver or heart to replace a failing one? Some scientists believe that could be possible with 3-D printing. Advances in 3-D printing technology since its debut in the 1980s have led to its use today for making everything from toys to wind turbines. Printed prosthetics and bone implants are already possible; living body parts, some say, will soon follow. But making a functioning human organ entails developing the right types of cell-loaded inks, laying them down in intricate patterns, and getting nutrients to the newly formed tissues challenges for chemists and materials scientists. The company Organovo has already printed layers of bioinks containing living cells to create slivers of liver tissue for chemical and drug testing. They began offering kidney tissue this month and are now working on printed skin. Sharon Presnell, Organovo’s chief scientific officer, says that it should be possible to print tissue patches to repair failing human organs within the decade. And in November 2015, one company in Russia reported printing and testing a functional thyroid gland in living mice. “Ultimately people will tackle the ‘o’ word,” says Jennifer A. Lewis, a materials scientist at Harvard University, referring to whole, fully functional human organs like kidneys and livers that could save thousands of lives and millions in healthcare costs. Although human tests are far away, the idea is to use cells harvested from the patient so the tissues are accepted by the immune system. Whether or not these body parts look like the real thing, they would do the same job. And 3-D printing would allow them to be printed on-demand, in hours, and for a low cost. “There has been incredible progress in the past decade, and when I translate to the next 10, 15 years, I envision that we should be able to print large-scale, complex organs”, says Ibrahim Ozbolat, a professor of engineering science and mechanics at Pennsylvania State University. “I’m not saying they will be transplanted in humans, but we’ll be making them.”