3D printed organs will greatly facilitate surgery by alleviating the need of an organ donor waitlist. Source: http://www.flickr.com/photos/armymedicine/

3D printed organs will greatly facilitate surgery by alleviating the need of an organ donor waitlist. Source: http://www.flickr.com/photos/armymedicine/

With each new breakthrough in biologically printed organs, the organ donor waitlist gets closer to becoming obsolete. In May 2013, doctors saved a six-week old child with a 3-D printed trachea (1), and researchers in China have more recently claimed to succeed in printing a pair of living kidneys (2).

Biologically producing organs first started by building artificial scaffolds in the shape of human body parts. Scientists would then grow living cells on those scaffolds to create the desired organ. The problem, however, was three-fold. First, the scaffold material had to be chosen carefully so that its dissolution would not affect living cells (3). This would prove to be especially difficult with organs that required many different types of cells. Second, the need to manually place living cells on the scaffold hurt the precision of the product. And third, foreign materials could cause inflammation of the cells.

Scientists have, thus, turned to 3-D printers and stem cells. Instead of building a scaffold for cells to grow on, 3-D printers put certain types of cells in the “correct” place so that they self-organize and grow on each other. These types of cells are made from the patient’s own stem cells, taken from his or her own fat or bone marrow, in order to eliminate the possibility of the patient’s body rejecting the transplant (graft-versus-host-disease).

Although bioprinting has been successful and avoids many of the problems associated with scaffolds, many difficulties still persist. Due to the lack of structure in printing these organs, the strength of the organ poses a challenge to researchers. Furthermore, 3-D printers currently lack the necessary software to print the most complex of organs.  Unlike an inanimate object, organs have no clear blueprint. While a 3-D scanner can analyze the exact shape of a cup, a scanner currently doesn’t exist for organs.

According to Hod Lipson, a Cornell engineer and co-author of Fabricated: The New World of 3D Printing, “An MRI doesn’t tell you where the cells are. We’re just completely in the dark in terms of the blueprints. That’s half the puzzle. There’s also no Photoshop—no tools to move cells around. That’s not a coincidence. It’s beyond what most computer software can handle. You can’t have a software model of a liver. It’s more complicated than a model for a jet plane.” (4)

Current 3-D printers also have a difficulty with printing tiny blood vessels that measure 50 microns or smaller. Researchers agree, however, that 3-D printers only have to print the structure of organs and let the cells’ self-organization tendencies do the rest.

“We will be printing things on the order of tens of microns, or more like hundreds of microns, and then cells will undergo their biological developmental response in order to self-organize correctly,” Stuart Williams, head of the Cardiovascular Innovation Institute, said. “Printing is only going to take us partway.” (3)

For now, biologically printing organs is in its early stages of development, but as scientists improve on the technology, the implications would be widespread. With an average of 18 deaths per day due to the shortage of donated organs (5), commercially producing vital organs for transplants could eliminate this shortage and save thousands of lives a year. More subtly, researchers believe that organs can be printed with a chip that tests the affect of different chemicals and medications on the body. Commercially printed tissues could be on the market within the next 10 to 15 years, saving many lives in the future (6).

 

References:

1. Fessenden, Marissa. “3-D printed windpipe gives infant breath of life” (2013). Available at http://www.nature.com/news/3-d-printed-windpipe-gives-infant-breath-of-life-1.13085 (3 October 2013)

2. Gidalevitz, Yona. “Researchers Claim to Successfully 3D-Print Living Kidneys” (2013). Available at http://www.medgadget.com/2013/09/researchers-claim-to-successfully-3d-print-living-kidneys-video.html (3 October 2013)

3. Hsu, Jeremy. “3D Printing Aims to Deliver Organs on Demand”. (2013) Available at http://www.livescience.com/39885-3d-printing-to-deliver-organs.html (3 October 2013)

4. Leckart, Steven. “How 3-D Printing Body Parts Will Revolutionize Medicine”. (2013) Available at http://www.popsci.com/science/article/2013-07/how-3-d-printing-body-parts-will-revolutionize-medicine (3 October 2013)

5. Organ Procurement and Transplantation Network. “Organ Donation Statistics”. (2013) Available at http://www.donatelifeny.org/about-donation/data/ (3 October 2013)

6. Hsu, Jeremy. “Tiny 3D-Printed Organs Aim for ‘Body on a Chip’”. (2013) Available at http://www.livescience.com/39660-3d-printed-body-on-a-chip.html (3 October 2013)