Construction of urethras for injured boys in US moves science a step closer to growing replacement body parts
guardian.co.uk, Associated Press, Tuesday 8 March 2011
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| US doctors made urethras for five boys in Mexico after they were injured in accidents. Photograph: Olivier Pirard/Rex Features |
Doctors have created urethras using patients' own cells for the first time, providing another example that scientists may be able to grow replacement body parts one day.
American doctors made the urethras for five boys in Mexico, aged 10 to 14, after they were injured in accidents several years ago.
The urethra is a thin tube that carries urine out of the body from the bladder; cells from both organs are very similar. Tissue grafts are normally used in such cases, but there's a less than 50% success rate.
After removing a postage stamp-sized section of cells from the boys' bladders, scientists put the cells into a special mixture in a laboratory to speed up their growth. They then constructed a tiny mesh tube out of the same material used for dissolvable stitches in surgeries to act as a scaffold. The tube was alternately coated with muscle cells on the outside and lining cells on the inside.
Dr Anthony Atala, a professor of surgical sciences at the Wake Forest University school of medicine in North Carolina, described the process as "very much like baking a layer cake".
He said the new structure was put into an incubator for several weeks before being implanted in the patient. The scaffold eventually disintegrated, leaving the patient's own cells as a new urethra.
Up to six years after having their new urethras implanted, Atala said the boys' organs were fully functional and no major side effects were reported. "It's like they now just have their own urethras."
Atala said the techniques used might be applied to create more complicated tubular structures in the body, like blood vessels. She and her colleagues have previously made bladders using patients' own cells.
The urethra research was paid for by the National Institute of Diabetes and Digestive and Kidney Diseases and the National Institutes of Health. It was published online in the medical journal Lancet.
In recent years, doctors have made new windpipes for patients partly from their own stem cells.
A tissue engineering expert at Bond University in Australia, Patrick Warnke, and his team have grown a replacement jaw and they are now working on an eye.
"It's not so much science fiction anymore to think we can grow replacement organs," Warnke said.
He also said he thought it was possible that children, who heal faster than adults, might be better candidates for such procedures in the future, though that could raise ethical dilemmas.
"Tissue regeneration is much faster in children, but my gut feeling tells me not to do it," he said. "If you mess it up in a child, it will be horrific."
Other experts said using science to reconstruct body parts was the ultimate medicine.
Chris Mason, the chair of regenerative medicine bioprocessing at University College London, said in a statement: "When an organ or tissue is irreparably damaged or traumatically destroyed, no amount of drugs or mechanical devices will restore the patient back to normal.
"If the goal is cure, then cell-based therapies are the answer."
Related Article:
“How do you create a new cellular tissue pattern? You change its magnetic structure. There are systemic instructions you can give your cellular structure to build new tissue that was never there before. I've told you this many times in the past and here it is again. There'll come a day when you can grow back an arm and a leg. How? All you have to do is to give DNA new systemic instructions. The old instructions tell it to only accomplish this in the womb. Change the instructions!” Read more ….. DNA Layer Nine - The Healing Layer - May 2010 (Kryon channeled by Lee Carroll)
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