Back in the August 2012 issue of Focus, we featured a story about a man who lost his nose to cancer and is now growing a new one on his arm. The story was this week picked up by the world's media, with the Daily Mail reporting on the pioneering treatment. Here's your step-by-step guide to how University College London's Professor Alex Seifalian is producing this prosthetic proboscis...
1) A mould of the patient’s original nose is taken prior to its surgical removal. This mould is used to create a second mould – made of glass – into which a polymer scaffold is sprayed. Cells from the patient’s bone marrow are grown in the lab and then added to the nose scaffold, which is placed in a bioreactor – a large jar-like container that rotates.
2) For about two weeks, the bioreactor is maintained at body temperature (37°C), which helps the cells to grow all over the scaffold. At the same time, a small balloon is placed under the skin on one of the patient’s arms. Every few days this balloon is inflated a little more to encourage the skin to stretch.
3) The scaffold, covered in the patient’s cells, is removed from the bioreactor and surgically implanted under the stretched skin on the patient’s arm, where it will remain for three months as it develops a blood supply. The nose, together with its new skin, is then extracted from the arm and surgically attached to the patient’s face.
4) Attaching the nose is a complex, delicate procedure because many tiny blood vessels need to be reconnected. If this operation is deemed a success, the surgical team will later remove the skin covering the nostrils. Mucous membrane cells derived from the patient will then be implanted into the nostril cavities, producing a functional organ.
The UCL scientists are currently at step 3 – the nose is now implanted in the man's arm. Once transferred to his face, it's hoped that the nose will provide the patient with a sense of smell. The man has even asked for his new proboscis to be slightly bent to the left, just as his old one was.
Illustrations by Paul Wootton
For our full 'How to Grow Your Own Body' feature, check out the August 2012 issue of Focus.