March 28 - Researchers in Boston are in the final stages of testing a new technique to fabricate a fully functional human ear with a patient's own cells. Using scans, computer modelling and 3D printing, the scientists say their research heralds a new era of regenerative medicine. Ben Gruber reports.
This rat has three ears…the two it was born with and another that has been growing on its back for the past 6 weeks. It's all part of an experiment that researchers from Massachusetts General Hospital say will one day give people who've lost an ear the option to have a new one grown in a laboratory. Research engineer Tom Cervantes says the process starts by scanning a patient's existing ear. (SOUNDBITE) (English) TOM CERVANTES, RESEARCH ENGINEER, SAYING: "We can take a CT scan of any shape and then import the image into our computer programs and then be able to print that out. And so what that means we can do is take scan of someone's ear and then be able to take the mirror image of that and print that out." That plastic printout becomes a mold which is then cast with what Cervantes calls a collagen slurry - a mix of fibrous proteins that give ears their flexibility. (SOUNDBITE) (English) TOM CERVANTES, RESEARCH ENGINEER, SAYING: "And within the slurry a wire framework embedded. And that framework is important because it helps the ear to hold its shape while it is growing in vivo, inside of the animal." After the collagen mold and framework are ready, the scientists seed the ear with a patient's own cells to ensure it will be biocompatible. Cathryn Sunback, director of the tissue engineering lab, says that the rat is merely a test bed. Ears for humans will be grown in an incubator, as will more complex structures the team envisages like vascular networks for lungs and livers. (SOUNDBITE) (English) CATHRYN SUNBACK, DIRECTOR, TISSUE ENGINEERING LAB, MASSACHUSETTS GENERAL HOSPITAL, SAYING: "As the field acquires human knowledge it will give us the basis to go forward with the next step of complexities. Ultimately I think things like the liver are going to be the most complex. It is going to be challenging to overcome all of the obstacles. But I think if there is a staged approach over time that we will get to the point where we will ultimately engineer the most complex structures." But first, they want to get their ear generation technique into the public domain. They're hoping to win FDA approval for their technology by the end of the year, and help bring a new era of regenerative medicine into the mainstream.