WASHINGTON Printing out body parts? Cornell University researchers showed its possible by creating a replacement ear using a 3-D printer and injections of living cells.
The work reported last week 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.
Its part of the hot field of tissue regeneration, trying to regrow all kinds of 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 co-authored the research published online in the journal PLoS One.
This first-step work crafted a human-shaped ear that grew with cartilage from a cow, easier to obtain than human cartilage, especially the uniquely flexible kind that makes up ears. Study co-author Dr. Jason Spector of Weill Cornell Medical Center is working on the next step how to cultivate enough of a childs remaining ear cartilage in the lab to grow an entirely new ear that could be implanted in the right spot.
Wednesdays report is a nice advancement, said Dr. Anthony Atala, director of the Institute for Regenerative Medicine at Wake Forest Baptist Medical Center, who wasnt involved in the new research.
Three-dimensional printers, which gradually layer materials to form shapes, are widely used in manufacturing. For medicine, Atala said the ear work is part of broader research that shows the technology now is at the point where we can, in fact, print these 3-dimensional structures, and they do become functional over time.
Today, people who need a new ear often turn to prosthetics that require a rod to fasten to the head. For children, doctors sometimes fashion a new ear from the stiffer cartilage surrounding ribs, but its a big operation. Spector said the end result seldom looks completely natural. Hence the quest to use a patients own cells to grow a replacement ear.
The Cornell team started with a 3-D camera that rapidly rotates around a childs head for a picture of the existing ear to match. It beams the ears geometry into a computer, without the mess of a traditional mold or the radiation if CT scans were used to measure ear anatomy.
Kids arent afraid of it, said Bonassar, who used his then-5-year-old twin daughters healthy ears as models.
From that image, the 3-D printer produced a soft mold of the ear. Bonassar injected it with a special collagen gel thats full of cow cells that produce cartilage forming a scaffolding. During the next few weeks, cartilage grew to replace the collagen. At three months, it appeared to be a flexible and workable outer ear, the study concluded.
Now Bonassars team can do the process even faster by using the living cells in that collagen gel as the printers 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 patients own cells in the 3-D printing process. Spector, a reconstructive surgeon, is focusing on children born without a fully developed external ear, a condition called microtia. They have some ear cartilage-producing cells in that tissue, just not enough. So hes experimenting with ways to boost those cells in the lab, so we can grow enough of them from that patient to make an ear, he explained.
That hurdle aside, cartilage may be the tissue most amenable to growing with the help of 3-D printing technology, he said. Thats because cartilage doesnt need blood vessels growing inside it to survive.