In what is being hailed as a significant step forward, researchers from Weill Cornell Medical College and Cornell University have created a bioengineered ear that looks, feels, and will likely function like the real thing.
The bioengineered ear is the first to survive long-term and grow cartilage. If further studies pan out, the first person may receive a bioengineered ear in as little as 3 years. Potential candidates may include individuals with microtia and those who have lost all or part of their external ear due to trauma or cancer.
“They should restore hearing and a normal appearance to children and others in need,” says researcher Jason Spector, MD, director of the Laboratory for Bioregenerative Medicine and Surgery, associate professor of surgery of plastic surgery in the Department of Surgery at Weill Cornell Medical College, and an adjunct associate professor in the Department of Biomedical Engineering at Cornell University. Spector is also a plastic and reconstructive surgeon at New York-Presbyterian Hospital/Weill Cornell Medical Center in New York City.
The findings are published in PLOS ONE.
The team used 3D printing and new high-density collagen injectable gels to fashion ears that are identical to a human ear. The ears steadily grew cartilage to replace the collagen that was used to help mold them throughout the course of the 3-month study. The process is quick; taking about 1 week to construct the ear.
To make the ears, the research team took combination laser scans and panoramic photos of an ear from twin girls. They then converted that image into a digitized “solid” ear and used a 3D printer to assemble a mold. Next, they injected animal-derived high-density collagen into that ear mold, and then added nearly 250 million cartilage cells. They remove the ear 15 minutes later, trim it and then let it culture for several days before it is implanted.
During the 3-month observation period, the cartilage in the ears grew to replace the collagen scaffold. “Eventually, the bioengineered ear contains only auricular cartilage, just like a real ear,” Spector says. “Surgery to attach the new ear would be straightforward — the malformed ear would be removed, and the bioengineered ear would be inserted under a flap of skin at the site.”
J. Peter Rubin, MD, the Chair of the Department of Plastic Surgery at the University of Pittsburgh, reviewed the study for Plastic Surgery Practice. “A significant challenge for tissue engineering of the human ear is creating precise shapes that have long-term durability,” he says. “Spector and colleagues have taken a nice step forward in replicating the shape of the normal ear through advanced imaging and manufacturing methods, and producing viable cartilage [but] longer-term testing will be necessary to show durability.”