Add this to the list of cool things people are making with 3-D printers. A couple of physicians and biomedical engineers have grown artificial children’s ears in a lab using a combination of 3-D printing and cartilage cells supported by collagen. The research could advance reconstructive surgery for children born with a rare ear condition as well as help people who lose the external portion of their ears because of cancer or an accident.
The project is a joint effort between Cornell University and its medical school, Weill Cornell Medical College. It stems from efforts to develop replacement parts for humans that are mostly made of cartilage such as joints, trachea and the nose because it’s an easier process than a body part that needs to be connected to blood vessels, according to an emailed statement from Weill Cornell.
Here’s how it works: The physicians took a laser scan and panoramic photo of an ear from twin girls. That provided a 3-D image of their ears. The researchers used the 3-D image with a 3-D printer to generate a mold of the ear. They injected animal-derived, high-density collagen gel into the ear mold along with 250 million cartilage cells. Animal-based collagen is frequently used in reconstructive surgery because it acts like a scaffold. The cells were left for several days to develop in the cell culture. Altogether, the team estimated it to about one week to produce the ear.
Dr. Jason Spector, director of the Laboratory for Bioregenerative Medicine and Surgery at Weill Cornell, and Dr. Lawrence J. Bonassar, an associate professor of the department of biomedical engineering at Cornell University, were the lead co-authors of the study, which was published in PLOS One, a peer-reviewed open-access journal.
Bonassar said it takes half a day to design the mold, a day or so to print it, 30 minutes to inject the gel, and the ear can be removed 15 minutes later. “We trim the ear and then let it culture for several days … before it is implanted.”
Although scientists have tried to develop ears from cells before, previous attempts were stymied by the failure of these ears to maintain their dimension over a period of time and the cells contained in them died.
People who are born with the ear condition microtia frequently have a normal inner ear, but suffer from hearing loss because they are missing the external ear structure, which helps capture and conduct sound.
The research is in the early stages and would still need to be successfully tested with animals before advancing to clinical studies, though Spector said this stage may only be three years away. Still, they are trying to work out how to grow the cartilage cells faster. In an interview with National Public Radio, Bonassar said the researchers were still identifying what the perfect cell source for these implants should be, such as human ear cartilage or stem cells from a person’s bone marrow or fat.