Ears and noses could be grown in a laboratory and transplanted into humans using a technique developed by British scientists.
Researchers from the Great Ormond Street Hospital and University College, London using tissue engineering are the first to turn stem cells from body fat in the abdomen of children into living cartilage.
This revolutionary procedure could help young patients born with debilitating facial abnormalities such as microtia, in which the outer ear is underdeveloped, or those who require reconstructive surgery after an accident.
Experts believe that it could be used in many other types of transplant surgeries to reduce the risk of the body rejecting a replacement organ.
Currently, when facial features of children with severe birth defects need to be rebuilt, surgeons take cartilage from other parts of the body, such as the ribs, which is an invasive and painful procedure. Then they fashion the shape of a nose or an ear by hand, before placing this scaffold under the skin.
Doctors using the new technique would simply be able to “grow” a new ear or nose that would be biologically indistinguishable from the real thing.
To achieve the breakthrough, researchers combined stem cells from a child’s abdominal fat with a polymer ‘nano-scaffold’ — almost a microscopic netting.
They manipulated this composite in a laboratory so that human cartilage tissue grew into the tiny holes within the polymer.
The technique could now be used to help treat several conditions. For patients with microtia, for example, the stem cells that make the cartilage tissue could be placed in a mould so that it grew into the shape of an ear.
This “cartilage ear frame” would then be inserted under a flap of skin on a patient’s head which would mould around the shape. When a biodegradable polymer scaffold is used, it would dissolve, leaving only human cartilage.
Although it would not help with other functions, such as hearing, the ear would be biologically indistinguishable from a real outer ear.
A paper on the new technique has been published in the journal Nanomedicine: Nanotechnology, Biology and Medicine. Neil Bulstrode, consultant plastic surgeon at the Great Ormond Street Hospital, one of the authors of the research, said, “It is such an exciting prospect. If we could produce a block of cartilage using stem cells and tissue engineering, this would be the holy grail for our field.”
The research could also have wider implications for the future of transplants.
Significant advances have been made since the first synthetic tracheal transplant carried out in 2011 using a plastic windpipe coated in stem cells. Development of the technique means a windpipe could be created from cartilage made from a patient’s own fat stem cells, making rejection unlikely.
In the report, the authors said that the procedure could ultimately “help to improve stability, integration and functionality of engineered transplants while avoiding tissue rejection”.
The technique harvests mesenchymal stem cells from abdominal fat, which can be turned into cartilage cells. Ultimately, the scientists believe that it could be used to create bone and other types of tissue.
Patrizia Ferretti, the head of developmental biology at UCL, said that the technique was particularly useful for children. “One of the main benefits is that, because they are the patient’s own cells, you don’t have to do any immune suppression, which is not desirable for a child,” she said. “At the moment we take cartilage out of the ribs which means a major additional surgical procedure that creates a permanent defect, as the rib cartilage does not regrow.
“But with this technique you could seed the stem cells on to a mould of a healthy ear, or use 3D printing to make the ear shaped scaffold-containing cells that can then be turned into cartilage.
“That would reduce the number of severe procedures, hence be greatly advantageous for the child. We haven’t yet made a complete ear with material that is biodegradable, but I am hopeful we will in the not too distant future.”
This new approach could also allow children to have facial reconstructive surgery earlier. Surgeons must now wait until the child’s ribs have grown enough to provide sufficient cartilage for the ear.
But Ferretti said, “Our goal is that over time the synthetic component of the grafted ear would disappear and the grafted tissue will grow with the child.”
For Sam Clompus, 15, of Bristol, who suffers from microtia, the technique means that one simple operation could have restored his ear. He has just received a new ear through this procedure at the Great Ormond Street Hospital. He is delighted though his ribs are sore.
Sam was born with just a nub where his right outer ear should have been.
“Growing up, at times he was self-conscious,” said his mother Sue, 50, a senior lecturer in nursing.
“When he was younger they offered Sam a prosthetic ear but we thought that was a bit too Frankenstein.”
But the new technique would be less invasive.
“At the moment it is quite gruelling, particularly where they go in and take out the rib cartilage,” added Sue. “He was sore for a while after that. So the new stem cells technique would mean that a fairly large part of the procedure would not be necessary.”
About 7,000 people are affected by microtia in Britain but tens of thousands of babies are born with other kinds of facial abnormalities each year. And the technique could help people who have suffered severe damage in accidents or trauma.
Sunday Telegraph