In August 1997, Joseph Vacanti (now the Director of the Tissue Engineering and Organ Fabrication Laboratory at Massachusetts General Hospital in Boston and a group of scientists published a ground-breaking paper in the journal, Plastic and Reconstructive Surgery. In the journal, they showed a picture of a mouse with what appeared to be a human ear growing out of its back. This surreal image soon spread like wildfire as people emailed it to everyone they knew.
The picture often emailed without any caption on context didn’t take long to cause protest. Animal rights and right-wing religious groups were soon up in arms as they assumed that somehow someone had genetically altered a mouse’s DNA to grow ears. In October 11, 1999, the anti-genetics group, Turning Point Project, placed a full-page ad in the New York Times showing the photo of the mouse with the human ear, with a misleading caption that read, “This is an actual photo of a genetically engineered mouse with a human ear on its back”. However, this was totally untrue as the ear was merely “grafted” on the mouse with no involvement of genetics at all. In fact, the Pope and Catholic Church who have a strict anti-genetic stance have given its blessing to Vacanti procedure.
In April 1998 the British media was abuzz over a story that Jade Harris, from Middlesbrough, Britain would be the first girl to use the technology developed to grow the ear on the back of the mouse:
Girl may be first to grow artificial ear
A six-year-old girl could become the first person to grow an artificial ear using a controversial technique developed by American scientists…. Full Story
This gave false hope to many patients with similar problems much to the chagrin of the University of Massachusetts who were forced to send an email like this:
Thank you for your email of inquiry about the Massachusetts Eye and Ear Infirmary. While physicians at the Infirmary are working on a research project that deals with tissue engineering, we are nowhere near the point where we may be able to grow ears for people. We are not even in the human studies stage of this process. Unfortunately, there is quite a bit of misinformation in the British press, especially regarding Jade Harris. If Jade does come to the Infirmary for treatment, it will be for regular surgery that would use some of her rib-bone to reconstruct her. We will not be growing Jade an ear in a test tube because we are not able to do that at this time. Please ask your local physician about treatments available to reconstruct ears. Best regards, Mary Leach, Director of Public Affairs”[BBC News]
The technique that Joseph Vacanti had spent years developing was growing cartilage over biodegradable moulds so that they could custom shape cartilaginous body parts, like ears. They used cartilage from a cows knee (There was no human tissue used at all in the procedure) placed it into a biodegradable mould shaped like a three-year-olds ear. To allow the cow cartilage to grow they needed a host which is the where the mouse came in.
As the immune system of most animals will reject foreign tissue the Vacanti team used a special nude mouse, a special type of mouse that through a rare mutation has a very weak immune system. These types of mice are very useful for tissue research as their bodies will not reject foreign tissues.
The cartilaginous ear was implanted under the skin of the nude mouse. Over time, the mouse grew extra blood vessels that supplied nourishment to the cow cartilage cells, that then grew into the biodegradable ear-shaped mould. The “ear” was never transplanted onto a human because it was grown from cow cells and would have been rejected by a person’s immune system.
Sean G. McCormack was born with a rare disease called Poland’s Syndrome which blocked the development of bone on the left-hand side of his chest. This left major organs like his lungs and heart unprotected by the rib cage. Dr. Joseph P. Vacanti and his brother, Dr. Charles A. Vacanti worked together using the same technology as was used with the ear on the mouse to “grow” a cartilage rib cage that within a year had developed into a normal-looking chest that was able to grow along with him.
Charles Vacanti predicts that within 20 to 30 years the same procedure could allow scientists to grow any organ, for example, a kidney or a liver, from a tissue sample.