March 8, 2011

expert reaction to paper in The Lancet on tissue-engineered urethras

A landmark study in which five boys each received a urethra grown from their own cells on a dissolvable scaffold; the engineered urethras functioned well for up to 6 years.

Prof Malcolm Alison, Professor of Stem Cell Biology and Leader of Centre for Diabetes, Barts and the London School of Medicine and Dentistry, said:

“Keeping the drainpipes open but not leaky:

“The urethra is a tube that connects the bladder to the outside world; constriction of this tube is not a pleasant experience! However, many people suffer this affliction through genetic inheritance or traumatic injury. Simply inserting a plastic tubular connection will not suffice in terms of controlled urinary output. This new study by Anthony Atala and colleagues from North Carolina reports that the condition can be cured by the science of ‘Tissue Engineering’.

“They constructed an artificial tube (scaffold) that would be dissolved in time by the body’s own enzymes, but not before they had ‘seeded’ the scaffold with the patient’s own cells that would naturally line the internal and external (muscular) surfaces of the urethra. In the five boys treated with these artificial urethras, the urethras have behaved perfectly for up to 6 years with no symptoms of incontinence. This success story follows a similar approach (also reported in the Lancet), pioneered in Spain, in which a section of a constricted windpipe was replaced by a graft coated with the cells of the recipient patient. Thus, cell therapy is becoming a reality that is benefiting patients now, not a distant promise so common in the reporting of ‘scientific breakthroughs’.”

Professor Chris Mason, Chair of Regenerative Medicine Bioprocessing, Advanced Centre for Biochemical Engineering, University College London, said:

“Totally grown in the laboratory, these urethras, living tubes which convey urine from the bladder, highlight the power of cell-based therapies. 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.

“Using living cells as ‘medicines’ is a major step-change in clinical practice. Cell-based therapies complement drugs and devices by aiming to cure the large unmet medical needs of our generation including: blindness, diabetes, heart failure, Parkinson’s disease and stroke.”

Professor Anthony Hollander, Arthritis Research UK Professor of Rheumatology and Tissue Engineering and Head of The School of Cellular and Molecular Medicine, University of Bristol, said:

“This is an exciting and important tissue engineering breakthrough that is particularly impressive because the patients were followed up for a long time, showing clear benefit of the technique for 3-6 years after implantation. The study shows us once again the power of regenerative medicine to transform the lives of patients with serious diseases.”

Tissue-engineered autologous urethras for patients who need reconstruction: an observational study, by Atlantida Raya-Rivera et al., published in The Lancet at 00.01 UK time on 8 March 2011.