Bioengineers have used 3D printing to create the first artificial ears that look and act like real ones, according to a new breakthrough study. Research from Cornell University in New York shows how prosthetic ears almost indistinguishable from natural ones can be 3D printed using gels made from living cells. Astonishingly, the ground-breaking study found that over a three-month period the artificial ears grew their own cartilage to replace the collagen used to mould them. “This is such a win-win for both medicine and basic science, demonstrating what we can achieve when we work together,” said study author Lawrence Bonassar, associate professor of biomedical engineering. Surgeons are now hoping that the prosthetic can be used to help children born with ear deformity, said co-author Dr Jason Spector, professor of plastic surgery at Weill Cornell Medical College. At present, replacement ears are usually constructed with materials that have an unnatural Styrofoam-like consistency "A bioengineered ear replacement like this would also help individuals who have lost part or all of their external ear in an accident or from cancer," said Spector. To make the ears, the scientists start with a digitised 3D image of a human subject's ear. A 3D printer is then used to assemble a mould based on the scan and a 'living' collagen gel is poured in. When the mould is removed, the collagen serves as a scaffold upon which cartilage can grow. "It takes half a day to design the mould, 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," said Bonassar.