The team of scientists at the Laboratory For Tissue Engineering and Cellular
Therapeutics at Children's Hospital and Harvard Medical School, in Boston,
Massachusetts, harvested two different types of cells from biopsies of the
dogs' bladders, then ``seeded'' them onto preformed, bladder-shaped,
biodegradable polymers.
After 5 weeks in the laboratory, the muscle cells planted on the outside of
the polymer form and the urothelial cells on the inside had multiplied to
form a bladder that was architecturally and cellularly similar to a natural
bladder.
The researchers then implanted them into dogs. Within a month, the
artificial bladders were performing as well as natural bladders and
continued to do so for at least ten months.
``The tissue-engineered neo-bladders were able to function normally soon
after implantation,'' wrote the researchers. ''Structurally and
functionally, they were indistinguishable from native bladders.''
There are approximately 400 million people worldwide who suffer from bladder
disease, and a chronic shortage of suitable donors for patients who need a
transplant.
Previous attempts to use synthetic materials or natural materials to
manufacture artificial bladders have failed. But in the February issue of
the journal Nature Biotechnology, the researchers say their results show
that ``novel methods of tissue engineering can be employed for the creation
of anatomically and functionally normal bladders.''
In an accompanying analysis, Christian Lorenx, a consultant in the
department of pediatric surgery at the University Hospital in Mannheim,
Germany and Birgit Margareta Schaefer, a fellow in the department of
immunopathology at the University of Heidelberg, write that artificial
bladders may ultimately be useful for patients with congenital bladder
defects, but caution that the cancer patients may not benefit from this type
of technology, due to the possibility of cancer cells regrowing in the
artificial bladders created from their cells.
SOURCE: Nature Biotechnology 1999;17:133-134,149-155.