SEVEN youngsters spared a lifetime of incontinence and kidney infections: that was the heartening outcome that tissue engineer Anthony Atala was able to announce four years after transplanting lab-grown bladders into people born with spina bifida.
It is a milestone, to be sure, but one that also shows what a long road lies ahead for tissue engineering. Starting in 2002, Atala and his colleagues at Wake Forest University in Winston-Salem, North Carolina, seeded sacs of collagen with cells from the patients鈥� own vestigial bladders, and then cultured them for a couple of months before stitching the artificial organs, piggy-back style, onto the patients鈥� own.
The recipients are now doing reasonably well, but they are far from fully continent, and some urologists have pointed out that similar, if not better, results can be achieved using conventional surgery. This involves grafting a section of small intestine onto the bladder.
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From a tissue-engineering perspective, bladders are just the first challenge 鈥� and probably the easiest as they are little more than a simple bag. The ultimate goal is to grow solid organs such as livers and kidneys. Atala鈥檚 technique of seeding a scaffold of collagen may not be up to that task, according to some researchers who are experimenting with 3D cellular 鈥減rinting鈥� techniques adapted from ink-jet technology.
Meanwhile, conventional engineering is giving the tissue engineers a run for their money. In October, the US Food and Drug Adminstration approved a mechanical partial heart, designed to keep patients鈥� blood pumping while they are waiting for a transplant.
