The work of Dr. Anthony Atala and his colleagues at the wake forest University School of Medicine in North Caroline. USA, is a milestone in the field of regenerative medicine (the achievement was reported in The Lancet). Dr. Atala says, “ We have shown that regenerative medicine techniques can  be used to generate functional bladders that are durable. This suggests that regenerative medicine may one day be solution to the shortage of donor organs……. for those needing transplants. “The team grew artificial bladder in the laboratory using patients’ own cells. These were then successfully implanted in the patients and functioned for five years or longer.

The study’s patients all had spina difida, a birth defect that leads to incomplete closure of the spine. Their bladder tissue is hard, causing high pressure to build up and be transmitted to the kidney, where they cause kidney damage. They also have urinary leakage. An estimated 54,200 Americans develop bladder cancer each year and treatment often entails removal of the bladder. Many other lose their bladder as a result of congenital defects, infectious disease, injuries, diabetes and heavy metal poisoning. Surgeons traditionally replace the bladder by building a fluid reservoir using tissue from the bowel , but that procedure many problem, including reabsorption of toxins, formation of stones and kidney damage due to pressure buildup in the reservoir.

In this study, the researcher began by biopsying a small piece of bladder, about half the size of a postage stamp. The bladder tissue has three layer: muscle on the outside, a collagen supporting layer in the center and specialized urothelial cell on the inside to hold the urine. The muscle and urothelial cells were isolated and grown in the lob for about 30days. The cells involved are not stem cells, which in this case have the capacity to grow only into case have the capacity to grow only into other bladder cells. Meanwhile, using CT imaging of the patient to determine the size of the bladder, as scaffolding of a biodegradable polymer was constructed. The muscle and urothelial cells were then seeded onto the exterior and interior of the scaffold, respectively, and the entire construct grown in an incubator for two to three weeks.

A team of surgeons then removed scarred and diseased tissue from the patient’s own bladder and used the artificial tissue to rebuild the organ. As the final step, they wrapped the rebuilt organ in omentum, a membrane from the interior of the abdomen rich in blood vessels that supplies nutrients and Oxygen to the tissue, until it could grow its own vessels.

Atala’s team transplanted the artificial bladder in nine children, 4- 19 years old. Two of the patient dropped out of the study and could not be followed. In each  of the seven patient dropped out of the study and could be followed. In each of the seven patients studied, however, the tissue functioned successfully, ballooning as a real baldder does up to 10 times the normal size as it filled, without increasing pressure. The bladder also stopped leakage. The patient were studied for an average of 4.6 years before the team published its report.

Formal clinical trials of the bladder- building process could begin this year.