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How to make a replacement ear in just one week

Posting in Design

Cornell researchers have bioengineered the longest-lasting, most natural human ear yet. They hope to give children with a congenital ear deformity a new ear that's tailored to fit them.

Although children with microtia have a fully-formed inner ear, they have difficulty hearing without an external structure to conduct the sound. Multiple surgeries over several months -- using a Styrofoam-like material or cartilage from their own ribcage -- are painful options that rarely look and perform naturally.

  1. The team took a combination laser scan and panoramic photo to create a 3D image of a 5-year-old girl's ear on a computer screen.
  2. The image was converted into a digitized solid ear, and a 3D printer was used to make it into a mold.
  3. They filled it with an injectable gel made of living cells (specifically, dense animal collagen taken from rat tails) and added 250 million cartilage cells (harvested from cows). The collagen -- which has the consistency of flexible Jell-O -- served as a scaffold upon which cartilage could grow.
  4. After removing the ear from the mold, researchers trimmed it and let it culture.

After just a week, the fabricated ear seemed more like a natural ear than any previous attempts. Watch a video (which reminds me of the ear scene from Face Off).

"The process is fast," Cornell’s Lawrence Bonassar says in a news release. "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 a nourishing cell culture medium before it is implanted."

Three months later, the cartilage cells grew to replace the collagen scaffold.

The team hopes to use human cartilage cells in the mold in the future. If safety and efficacy tests work out, the first human implant could be in three years.

The work was published in PLOS ONE.

[Via PopSci, Cornell]

Images: Lindsay France/Cornell University Photography

— By on February 21, 2013, 6:53 AM PST

Janet Fang

Contributing Editor

Janet Fang has written for Nature, Discover and the Point Reyes Light. She is currently a lab technician at Lamont-Doherty Earth Observatory. She holds degrees from the University of California, Berkeley and Columbia University. She is based in New York. Follow her on Twitter. Disclosure