Hope springs eternal. And for people with trachea cancer and other untreatable cancers this may be the ultimate hope: an experimental procedure that involves transplanting adult stem cell-generated, bio-engineered synthetic organs to replace the ones damaged by cancer.
Like a number of organs, the trachea is fragile. Once it’s damaged, it’s difficult to get it to heal. Tracheal cancer, like many other cancers, can also be resistant to chemotherapy and radiation. People who suffer from this cancer often have to undergo renewed torment when their bodies reject transplanted donated organs or mechanical devices.
But in a novel and pioneering procedure, doctors used stem cells derived from a patients’ own bone marrow to generate new tissues, which are then used to fashion a new organ to replace the damaged one.
So far, the bioengineering experiment has had two successes, both transplants of synthetic windpipes, one in a 10-year old boy from the United Kingdom in 2010 and in November 2011, the successful transplant in a 30-year-old man from the United States.
Windpipe transplant success
Christopher Lyles, 30, of Abingdon, Maryland is the second lucky beneficiary of the bioengineering transplant procedure.
In June 2011, Lyles was diagnosed with a rare form of trachea cancer and between July and September, he underwent seven rounds of chemotherapy and 33 rounds of radiation treatment.
By November, his cancer had progressed to the point where it was considered inoperable. “Every surgeon told me it was inoperable,” Lyles tells ABC News. “It was hard to hear that.”
But when Lyles read about the experimental tracheal transplant procedure being performed by surgeons in Europe, he reached out to Dr. Paolo Macchiarini, the head surgeon in previous transplant cases. Dr. Macchiarini is the director of the Advanced Center for Translational Regenerative Medicine at Stockholm’s Karolinska Institute.
Lyles underwent the transplant in November and returned back to the U.S. on Jan. 11.
“What we did is (to) surgically remove his malignant tumor,” the New York Times quotes Dr. Macchiarini as saying. “Then we replaced the trachea with this tissue-engineered scaffold.”
Dr. Macchiarini started by extracting bone marrow from Lyles, then deriving bone marrow stem cells from this. Meanwhile, a Y-shaped scaffold was made from nano-sized fibers of PET, a plastic type used commonly in soda bottles.
The scaffolding was then covered or seeded with stem cells from Lyles’s bone marrow. It was then placed in a bioreactor—a shoebox-size container holding the stem cells in solution— and rotated like a rotisserie chicken to allow the cells to soak in, New York Times reports.
Special compounds called transcription factors were then used to help force the stem cells to differentiate into trachea-specific cells. The resulting “artificial” windpipe or trachea was biologically identical to Lyles’ original organ—and this was what was the transplanted into him.
Once the cells were inside the scaffold, they began to grow and divide and produce cartilage, David Green, president of Harvard Bioscience, the Massachusetts company that made the bioreactor, explains to the Times. “After two or three days, I think you can realistically call it tissue,” he says.
After two days in the bioreactor, it was installed in Lyles during an elaborate, 12-hour operation in which the new windpipe was sutured to his throat and lungs.
Once the windpipe was implanted, the cells continued to grow and differentiate without the need for transcription factors presumably because of chemical signals produced by the body, Dr. Macchiarini says. “We’re using the human body as a bioreactor to promote regeneration.”
Because it was not covered by medical insurance, the experimental procedure cost between US$300,000 to US$600,000, Lyles said. The family asked for about US $300,000 donation through the non-profit organization Help Hope Live, which works to fund uninsured transplant-related expenses.