A team of bioengineers and physicians at Cornell University, Ithaca, NY, have created an artificial external ear, using 3D printing and injectable molds, that looks and acts like a natural ear. This could give new hope to children born with a congenital ear deformity, or to those who have lost all or a portion of their ear in an accident or from cancer.
In a study published online in PLOS One, the biomedical engineers and Weill Cornell Medical College physicians described how 3D printing and injectable gels made of living cells can fashion ears that are practically identical to a human ear. Over a three-month period, these flexible ears grew cartilage to replace the collagen that was used to mold them.
Replacement ears are usually constructed with materials with a polystyrene foam-like consistency, or sometimes, surgeons build ears from a patient’s harvested rib. This option is challenging and painful for children, and the ears rarely look completely natural or perform well.
Beginning with a digitized 3D image of a human subject’s ear, the researchers then convert the image into a digitized “solid” ear using a 3D printer to assemble a mold.
The Cornell-developed, high-density gel is similar to the consistency of gelatin when the mold is removed. The collagen serves as a scaffold upon which cartilage could grow.
The process is quick, too. According to co-lead author Lawrence Bonassar, associate professor of biomedical engineering: “It takes half a day to design the mold, a day or so to print it, 30 minutes to inject the gel, and we can remove the ear 15 minutes later. We trim the ear and then let it culture for several days in nourishing cell culture media before it is implanted.”
They believe that if safety and efficacy tests work out, it might be possible to try the first human implant of a Cornell bioengineered ear in as few as three years.
