'New medicine' strives to heal wounded warriors
Scientists are growing ears, bone and skin in the lab, and doctors are planning more face transplants and other extreme plastic surgeries. The most advanced medical tools that exist are being deployed to help America's newest veterans and wounded troops.
• In Pittsburgh, doctors used an experimental therapy from pig tissue to help regrow part of a thigh muscle that Ron Strang lost in a blast in Afghanistan.
• In Boston, scientists are making plans for the first implants of lab-grown ears for wounded troops after successful experiments in sheep and rats.
• In San Antonio and other cities, doctors are testing sprayed-on skin cells and lab-made sheets of skin to heal burns and other wounds.
Much of this comes from taxpayer-funded research. Four years ago, the federal government created AFIRM, the Armed Forces Institute of Regenerative Medicine, a network of top hospitals and universities, and gave $300 million in grants to spur treatments using cell science and advanced plastic surgery.
“The whole idea is to bring all these researchers together to develop these great technologies that were in early science to eventually be ready for the troops,” said AFIRM's recently retired director, Terry Irgens.
Now those who served are coming home, and projects that once had been languishing in labs are making strides and starting to move into clinics.
Strang, 28, of Jefferson Hills is among those benefiting. The Marine Corps sergeant lost half of a thigh muscle to shrapnel, leaving too little to stabilize his gait. “My knee would buckle, and I'd fall over,” he said.
As a result of an experimental treatment through UPMC, “I'm able to run a little bit” and play a little football with friends, he said. “It's been a huge improvement.”
It's one example of the “new medicine” in the works for troops.
Muscles, bone and skin
A soldier lucky enough to keep his arms and legs after a bomb blast still might lose so much of a key muscle, such as biceps or quadriceps, that the limb cannot be used properly.
In some cases, “the patient has lost so much muscle that there's nothing left for the surgeon to sew together,” said Dr. Stephen Badylak, a regenerative medicine specialist at the University of Pittsburgh.
He is testing implants of “extracellular matrix” — connective tissue that holds cells together — to boost muscle mass. The matrix is thought to release chemical signals that promote regrowth of healthy tissue instead of scar tissue.
ACell Inc. of Columbia, Md., supplies the material, which comes from pigs. The immune system tolerates it because it does not contain cells. It comes in multi-layered sheets like slightly stiff gauze and can be cut or molded to fit the needed shape.
Strang is among the five patients treated so far in an 80-patient study.
In early testing, “they've shown up to 10 to 20 percent improvement” in strength of the muscle after treatment, said Irgens, the director of AFIRM, which funded some of the early work.
The Department of Defense is sponsoring the study under way now, which includes non-military patients as well as former troops. The new study is measuring changes in strength and muscle volume, and doctors are aiming for the kind of quality-of-life improvement Strang has enjoyed.
In other efforts, Pitt and Rice University scientists are working on growing bone to fix jaws and other facial defects. Researchers at Massachusetts General Hospital and Rutgers University are trying to grow eyelid muscles. Blindness can result from not being able to close an eyelid.
Doctors also are testing various ways to make skin. In one method, doctors take a postage stamp-sized piece of a patient's skin, process it in the lab and spray these cells onto a burn or other wound. The sprayer device that is used for this treatment is licensed in seven countries, and AFIRM is sponsoring a study aimed at winning U.S. approval.
The second approach uses sheets of skin developed from cells in the lab that originally came from foreskin removed in circumcisions.
“That's in clinical trials now, and they're having tremendous results,” Irgens said.
As many as a thousand troops might need an ear, and prosthetics are not a great solution.
“People have been working on this for 20 years,” said Cathryn Sundback, director of the tissue engineering lab at Massachusetts General.
Her lab thinks it's found the solution. Using a computer model of a patient's remaining ear, scientists craft a titanium framework covered in collagen, the stuff that gives skin elasticity and strength.
They take a snip of cartilage from inside the nose or between the ribs and seed the scaffold with these cells. This is incubated for about two weeks in a lab dish to grow more cartilage. When it's ready to implant, a skin graft is taken from the patient to cover the cartilage, and the ear is stitched into place.
Scientists have maintained lab-grown sheep ears on those animals for 20 weeks, proving it can be done successfully and last long-term.
They also have grown anatomically correct human ears from cells. These have been implanted on the backs of lab rats to keep them nourished and allow further research. Ears destined for patients would just be grown in a lab dish until they're ready to implant.
“It's amazing how much progress we've made with the AFIRM funding,” Sundback said.