Militarys AFIRM Research Funds Research Growing Human Ear Transplants on the Backs of Lab Rats

Laboratory rat implanted with a human-scaled ear made from sheep cells at the lab in Boston. (Photo: AP/Steven Senne)

BOSTON (TheBlaze/AP) – Don’t be surprised. This is not the first time a human ear has been grown on a lab rat, but recent successful tests mean the first transplant of a lab-grown ear onto a human recipient, specifically a wounded soldier, could come within the next year.

Four years ago, the federal government created the Armed Forces Institute of Regenerative Medicine (AFIRM), a network of top hospitals and universities, and gave $300 million in grants to spur new 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.

One of AFIRM’s research areas is craniofacial reconstruction, which its website describes as a “complex area” due to different tissue types and other factors:

Currently available synthetic materials do not remodel and integrate with host tissue and can become infected and require extensive, multiple revision surgeries. Metallic devices lack controlled delivery capability for biological factors and transiently restore anatomical form with limited function. Contemporary treatments do not restore neurogenic competence or mitigate against scars. Transplanted human tissues are the most promising option but are inadequate to treat craniofacial deficits incurred in combat in their current state.

For these reasons, the researchers are working on developing new polymers and tissues to better serve the needs of wounded soldiers.

Taking the ear as an example, prosthetics are not a great solution as it requires a rod or other fastener to attach them to the head. They don’t look or feel natural and they wear out every couple of years. A matching ear grown from a patient’s own cells would be a huge improvement.

Militarys AFIRM Research Funds Research Growing Human Ear Transplants on the Backs of Lab Rats

Cathryn Sundback, director of the tissue engineering lab at Massachusetts General Hospital hopes this technique for growing ears with human cells could be used in a year. (Photo: AP/Steven Senne)

“People have been working on this for 20 years” but haven’t been able to overcome obstacles to making it practical, said Cathryn Sundback, director of the tissue engineering lab at Massachusetts General Hospital.

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.

Militarys AFIRM Research Funds Research Growing Human Ear Transplants on the Backs of Lab Rats

(Photo: AP/Steven Senne)

Scientists in her lab 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. But that wouldn’t happen with ears destined for patients – they would just be grown in a lab dish until they’re ready to implant.

Militarys AFIRM Research Funds Research Growing Human Ear Transplants on the Backs of Lab Rats

(Image: Dr. Joseph Vacanti, Harvard University via AFIRM)

Militarys AFIRM Research Funds Research Growing Human Ear Transplants on the Backs of Lab Rats

(Photo: AP/Steven Senne)

“We’ve solved all the technical problems,” Sundback said, and now they are ready to seek approval from the Food and Drug Administration to implant these into patients – probably in about a year. “It’s amazing how much progress we’ve made with the AFIRM funding.”

In 2011, PBS’ NOVA featured part of this research of growing ears. Watch the clip: