Pig Bladders Used to Successfully Grow and Regenerate Human Muscle

Pig bladders have been successfully used to regenerate leg muscles in mice and humans, according to researchers at the University of Pittsburgh School of Medicine and the McGowan Institute for Regenerative Medicine. The study, which implanted pig bladder derived extracellular matrix (ECM) into the legs of five human participants who had a 25 percent or more loss in leg muscle volume, found that injured muscle grew stronger and demonstrated signs of regeneration in three out of the five participants. The findings were published in Science Translational Medicine.

“This new study is the first to show replacement of new functional muscle tissue in humans, and we’re very excited by its potential,” said McGowan Institute deputy director Stephen F. Badylak, D.V.M., Ph.D., M.D., in a University of Pittsburgh news release. “These are patients who can’t walk anymore, can’t get out of a car, can’t get up and down from a chair, can’t take steps without falling. Now we might have a way of helping them get better.”

Researchers found that three out of five participants with thigh or calf injuries were at least 20 percent stronger, six months after the ECM implantation. Further, biopsies and scans revealed that muscle growth did occur, which led to one patient improving in the “single hop test” by 1,820 percent, and another patient who improved in the same test by 352 percent and improved 417 percent in the chair lift test. Although the other two participants did not have as dramatic results, they did demonstrate improvement on one or more functional measures and noted they felt better.

“This work represents an important step forward in our ability to repair tissues and improve function with materials derived from natural proteins. There will be more options to help our patients,” stated lead surgeon J. Peter Rubin, M.D.

The study was sponsored by the U.S. Department of Defense, the U.S. Department of the Interior, and the National Institutes of Health.