Lucky Liko, Lucky Us
Excerpted from UPMC Health Journal magazine, July/August 2005
A new treatment discovered by a researcher at the University of Pittsburgh Medical Center can heal injuries too severe to heal by themselves, like gaping wounds and second degree burns. It has repaired hernias and eased suffering from leg ulcers caused by diabetes. This new therapy has helped some 500,000 people. And one dolphin.
In spring 2004, Liko the dolphin suffered a serious injury to the base of his dorsal fin, that tell-tale wedge you see cutting through the water as dolphins swim offshore. Stretching nearly a third of the way through his fin and very wide, the cut wasn't mending well by itself: there was just too much of a gap for the healing process to span.
Fearing that Liko would lose his dorsal fin to further injury or infection, Dolphin Quest Hawaii asked UPMC researcher Stephen Badylak for help.
Twenty years ago at Purdue University, Dr. Badylak was investigating pig intestine as a potential substitute for blood vessels, thinking that since they share the same tubular shape, perhaps one could substitute for the other. The initial experiment failed: The innermost layer of the intestine ate away at the stitches that held it in place. But as Dr. Badylak's team refined the material, they identified a particular layer of intestine — the middle layer — that not only was kind to stitches but, when grafted into a blood vessel, was soon replaced by a healthy, functioning, normal looking blood vessel, good as new.
Dr. Badylak wondered what other body parts might regenerate with SIS — short for small intestinal submucosa, the name of the particular layer of gut the material comes from. In research with different body parts and systems, he found that almost anywhere SIS was put, "constructive remodeling" occurred: Rather than scar tissue, the appropriate cells were attracted to SIS and flourished. When Dr. Badylak spliced SIS into an artery, soon a new section of artery appeared. He placed it into a deep cut, and all the complex layers of muscle, fat, and skin regrew. He patched up a urinary bladder, a tendon, a ligament, even a heart.
Stripped of pig cells and sterilized, SIS is a felt-like, light pink sheet chock full of collagen, the protein that makes up most of our skin, bones, cartilage, and tendons. SIS also contains growth factors, substances that guide cells to develop into specific kinds of tissues.
Dr. Badylak had developed a new kind of transplant. Not of a limb or an organ, but of a robust healing environment, suitable for many different locations.
Liko didn't get a SIS treatment, but a similar scaffold derived from pig bladder. (With the success of SIS, the medical marketplace now offers many natural scaffolds from a variety of animal and human sources.) One of Dr. Badylak's graduate students custom-designed a scaffold to fit Liko's wound, and another protégé went to Hawaii to implant it. A specially designed wetsuit kept the dressing in place and Liko got LED light therapy to further boost healing, although a second scaffold treatment was needed to completely fill in the wound. "Now he's perfectly normal. You wouldn't even know that there was an injury there," says Dr. Badylak.