3D printing used to create artificial ears

The prosthetic ears are said to be almost indistinguishable from natural ones, and could be the solution reconstructive surgeons have long wished for to help children born with ear deformity. "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 Lawrence Bonassar, an associate professor of biomedical engineering at Cornell University. Replacement ears are usually constructed with materials that have a Styrofoam-like consistency, or sometimes, surgeons build ears from a patient's harvested rib. This option can be painful, however, and the ears rarely look completely natural or perform well. To make their 3D printed ears, the Cornell University team started with a digitised 3D image of a human subject's ear and converted the image into a mould using a 3D printer. They injected the mould with collagen derived from rat tails, and then added 250million cartilage cells from the ears of cows. The high density gel is said to have a similar consistency to jelly, with the collagen serving as a scaffold upon which cartilage can grow. Bonassar asserted: "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." The researchers are now looking at ways to expand populations of human ear cartilage cells in the laboratory so that they can be used in the mould, instead of cow cartilage. "Using human cells, specifically those from the same patient, would reduce any possibility of rejection," Spector concluded.