In 2011 Anthony Atala, Director of the Wake Forest Institute for Regenerative Medicine, caused a stir when he printed a human kidney on stage at the TED conference. This wasn't the first time that human tissue had been 'printed' (although it was probably the first time it was done in public) and the kidney wasn't functional but it was a powerful demonstration of what was, and could be, possible.
According to the Organ Procurement and Transplantation Network, a division of the U.S. Department of Health and Human Services, there are 114,831 patients awaiting a transplant in the U.S. alone, with about 80% of these needing a new kidney. By contrast, just 6,838 transplants were performed in the first quarter of 2012. This means that, if no new patients were added to the transplant list, it would take over four years to operate on all of them – assuming they survive long enough and a donor organ is found for every patient who needs one.
Obviously, the situation is far complicated than this; finding a suitable donor organ is no easy task, the surgery involved is risky and the danger of post-operative complications and organ rejection is high. In addition, of course, the transplant list grows larger over time; in Germany, for instance, 11,000 new patients were added to the organ transplant waiting list in 2011 alone.
The ideal solution to this problem would be to grow human organs in a laboratory, eliminating the need for organ donors and all the inherent risks of transplant surgery, and this is where 3D printing comes in. Atala used a CT scanner to build up a 3D image of the patient's kidney and a small tissue sample from the patient, which the printer then used to create the duplicate kidney one layer at a time. However, the 'duplicate' lacked blood vessels or internal structures and, to date, no one has successfully integrated these to create a functioning organ.
Atala's work has shown what is possible and the race is on to engineer blood vessels to supply artificial organs. For instance, a team at the Fraunhofer Institute in Germany is using a technique called multiproton polymerisation, combined with 3D printing, to create artificial capillaries. The technique appears to be promising, with the artificial vessels working well in laboratory tests.
The idea, eventually, will be to combine the two technologies and integrate organ tissue with artificial blood vessels to create fully functional organs. It's surely only a matter of time before this happens and, when it does, the agony of dialysis and the seemingly endless wait for a donor organ will become a thing of the past.
by Anthony Morgan