For the first time scientists have built the first functional anal sphincters that maintains the constriction of a body passage. This engineered sphincters may help treat fecal, urinary incontinence.
Made from muscle and nerve cells, the sphincters developed a blood supply and maintained function when implanted in mice.
"In essence, we have built a replacement sphincter that we hope can one day benefit human patients," said senior author Khalil N. Bitar, Ph.D., a professor of regenerative medicine at Wake Forest Baptist Medical Centre's Institute for Regenerative Medicine.
"This is the first bio-engineered sphincter made with both muscle and nerve cells, making it 'pre-wired' for placement in the body," he said.
There are numerous sphincters in the human body, including those that control the release of urine and faeces.
There are actually two sphincters at the anus - one internal and one external. Faecal incontinence is the result of a weakened internal sphincter.
Current options for repair of the internal anal sphincter include grafts of skeletal muscle, injectable silicone material or implantation of mechanical devices, all of which have high complication rates and limited success.
Numerous laboratory tests of the engineered sphincters, including stimulating the nerve cells, showed normal tissue function, such as the ability to relax and contract.
The engineered sphincters also developed a blood vessel supply and continued to function like native tissue when implanted under the skin of mice.
"The engineered sphincters were physiologically similar to native tissue. This takes us one step closer to realizing the goal of using a patient's own cells to engineer a replacement sphincter in the lab," stated Bitar.
The discovery was reported in the medical journal Gastroenterology.