Wake Forest Inst. Regenerative Medicine

Watching human organs take shape in a lab dish is no longer the realm of science fiction: as scientists get better at applying engineering techniques to living cells and tissues, lab-grown organs are increasingly becoming a reality. And this week, researchers at Wake Forest University report that they have for the first time successfully created a urethra that worked in human patients.

The research team, led by Dr. Anthony Atala, director of the Wake Forest Institute of Regenerative Medicine, began with a biodegradable scaffolding molded roughly into the shape of a thin tube to resemble a human urethra. The urethra is responsible for transporting urine waste outside of the body, and in men, can be narrowed by disease or damaged by trauma. Atala’s group then seeded the scaffold with bladder cells from the patients who would be using the tubes. This way, the tissue was the patients’ own.

Once transplanted, the urethras acclimated to their new environment and completed their development, until eventually, they started to function just as healthy urethras. Over time, the scaffolding eventually dissolves, much like biodegradable surgical sutures do, as new cells take over and maintain the integrity of the tissue. In a trial involving five boys with damaged tissues, Atala reports in the journal Lancet that all five of the transplanted urethras worked well in removing urine for up to six years.

“The cells know what to do,” Atala says of the remarkable feat of growing the tissue in a lab dish. “What you are getting when you create these urethras is normal tissue. It’s amazing to see.”

Atala is no stranger to such sci-fi-like achievements. Several yeas ago, he was the first to grow a human bladder using a similar scaffold technique seeded with human cells, and in 2008, the organ was transplanted for the first time into patients. He’s hoping to do the same with other organs that are either hard to replace or difficult to find donors for, and he doesn’t see any reason why the strategy couldn’t be applied to most tissues and organs. “We’re basically taking cells from some patients and putting them back into the same patients so the tissue becomes their own in the end,” he says.

So far, the boys who received the bioengineered urethras are doing well, and unlike other patients who receive grafts from other tissues, these boys may not need to replace their urethras every few years. At the moment, the cost of the procedure may be a deterrent, since it requires a $5,000 investment in materials and equipment, but Atala hopes that with the right commercial interest, the technique could be standardized and that production costs might come down. That would certainly be welcome news not just to people with urethral damage, but those who might benefit from other tissues and organs generated from this method as well.