A patient with tracheal cancer was given a new trachea grown entirely in a lab from his own stem cells using a synthetic scaffold. The cancer has been diagnosed as terminal, but thanks to the surgery, the man is likely to be discharged in a few days. As Gautam Naik at the Wall Street Journalreports:
"It's yet another demonstration that what was once considered hype [in the field of tissue engineering] is becoming a life-changing moment for patients," said Alan Russell, director of the McGowan Institute for Regenerative Medicine in Pittsburgh, who wasn't involved in the latest operation. . . With the patient on the surgery table, Dr. [Paolo] Macchiarini and colleagues then added chemicals to the stem cells, persuading them to differentiate into tissue—such as bony cells—that make up the windpipe. About 48 hours after the transplant, imaging and other studies showed appropriate cells in the process of populating the artificial windpipe, which had begun to function like a natural one. There was no rejection by the patient's immune system, because the cells used to seed the artificial windpipe came from the patient's own body. Dr. Russell of the McGowan Institute sounded a note of caution about using this technique to build more-complex organs. For example, while tissue engineering can help to build hollow organs such as a windpipe, it will likely prove a bigger challenge to use the technique for creating the heart, which has much thicker tissue.
The use of a synthetic scaffold is landmark for two reasons. First, it means that those in need of a trachea transplant don't have to wait for a donor trachea. Stem cells can be used to make one to order. Second, previous lab-grown tracheae had used tracheae from cadavers as scaffolds. The use of a fully synthetic scaffold means that only the patient's own cells create the new organ. As a result, the body recognizes the new organ as its own and does not attempt to reject it, removing the need for immunosuppressive drugs. The success of this operation creates the foundation for other lab-grown organs because the only two necessary ingredients were stem cells and synthetic scaffolds. No need for donors, cadavers, or immunosuppressive drugs. The implications for anti-aging medicine are incredible: imagine being able to get a new set of organs dropped in every twenty years or so. Brand new heart, lungs, and guts fresh from the factory. Or, if you're born with a bad ticker or digestive issues, no worries, we'll just whip you up a new one and swap it out. It would be a paradigm shift in the treatment of disease. The possibilities here are tremendous, but also a long ways away. Dr. Russell is right when he calls out the simplicity of the trachea in relation to other organs. The trachea is the first small step of many large steps science still needs to take before we can readily and safely replace any organ in the body. Still, that a man's life was saved by a technology that was science fictional two decades ago is a cause worth celebrating. Follow Kyle on his personal blog, Pop Bioethics, and on facebook and twitter.
