11 July 2011
ByAppeared in BioNews 615
Surgeons have successfully transplanted a synthetic organ into a human for the first time. In a groundbreaking operation, a cancer patient's windpipe was replaced with an artificial replica that had been grown using his own stem cells.
An international team of doctors and scientists created the artificial windpipe without using any tissue from an organ donor. As well as cutting waiting times for transplants, this technique will be important in cases where a suitable donor can't be found, which can be a particular problem for children. Furthermore, the use of the patient's own stem cells meant there was no risk of it being rejected, and he did not need to take immunosuppressive drugs.
The 36-year-old man had an aggressive tumour that had not responded to chemotherapy or radiotherapy, and it was inhibiting his breathing. With no suitable donor organ available the medical team decided to try the new technology. 'He was condemned to die', Professor Paolo Macchiarini, the lead surgeon, told the Wall Street Journal, only a month after the 12-hour operation. 'We now plan to discharge him'.
Professor Macchiarini, who works at the Karolinska University Hospital, Sweden, had previously carried out similar procedures, but always using the windpipe of an organ donor coated with the patient's stem cells. In this case, a 3D scan was taken of the patient's windpipe and a team of scientists at University College London (UCL) used the images to build an identical 'scaffold' out of a specially designed material called a nanocomposite polymer.
Stem cells taken from the patient's bone marrow were dripped onto the scaffold in a device developed by researchers at Harvard Bioscience Inc., USA. After two days these cells had populated the entire scaffold structure, and were then treated with chemicals to encourage them to form the right types of tissue. A similar technique has also been used to grow bladder tissue for use in reconstructive surgery.
Professor Alexander Seifalian, who led the research team at UCL said: 'What makes this procedure different is it's the first time that a wholly engineered synthetic windpipe has been made and successfully transplanted, making it an important milestone for regenerative medicine. We expect there to be many more exciting applications for the novel polymers we have developed'.
Remarkably, the whole process only took a few days. Professor Macchiarini commented: 'Thanks to nanotechnology, this new branch of regenerative medicine, we are now able to produce a custom-made windpipe within two days or one week… The beauty of it is you have it immediately. There is no delay'.