Scientists use 3-D printing to help grow replacement ear


Printing out body parts? Cornell University researchers have shown it is possible by creating a replacement ear using a 3-D printer and injections of living cells.

The work, reported Wednesday, is a first step toward one day growing customized new ears for children born with malformed ones, or people who lose one to accident or disease.

It is part of the hot field of tissue regeneration, trying to regrow body parts. Scientists hope using 3-D printing technology might offer a speedier method with more lifelike results.

If it pans out, “this enables us to rapidly customize implants for whoever needs them,” said Cornell biomedical engineer Lawrence Bonassar, who coauthored the research, published online in the journal PLoS One.

This work crafted a human ear that grew with cartilage from a cow, which is easier to obtain than human cartilage, especially the uniquely flexible kind that makes up ears. Coauthor Dr. Jason Spector of Weill Cornell Medical Center is working on the next step: cultivating enough of a child’s remaining ear cartilage in the laboratory to grow an entirely new ear that could be implanted in the right spot.

The Cornell team started with a 3-D camera that rotates around a child’s head to make a picture of the existing ear. From that image, the 3-D printer produced a soft mold of the matching ear. Bonassar injected it with a collagen gel that was full of cow cells that produce cartilage, forming a scaffolding. Cartilage grew to replace the collagen. At three months, it appeared to be a workable ear.

Now Bonassar’s team can do the process even faster by using the living cells in that collagen gel as the printer’s “ink.” The 3-D technology directly layers the gel into just the right ear shape for cartilage to cover, without having to make a mold first.

The next step is to use a patient’s own cells in the 3-D printing process. Spector is focusing on children born without a fully developed ear. They have some ear cartilage-producing cells in that tissue, just not enough. So he is experimenting with ways to boost those cells in the lab “so we can grow enough of them from that patient to make an ear.”