Organ/tissue 2.0

As amazing and complex as the science relating to organ replacement has become, there are still some fundamental problems. Patients require significant levels of immunosuppressant drugs to stop their bodies destroying their new organs, making them vulnerable to illness. Complex organs will have a limited lifespan, lasting between 10 and 25 years subject to the patient, their lifestyle and the health of the donor organ. Then there is the issue of how these donor organs are obtained in the first place – an ethical issue that only a handful of European countries have got to grips with by making organ donation an automatic process upon the death of a citizen.

The use of the first artificial trachea offers a breakthrough, as the technique bypasses many of the negative factors in transplant science. The first procedure on a human being saw a replacement organ built specifically for a Swedish patient who had been suffering from tracheal cancer and for whom all conventional treatment had failed.

Having followed research a team from University College London’s nanotechnology and regenerative medicine department, staff at the patient’s hospital requested their assistance. Led by Professor Alex Seifalian, the UCL team raced against the clock to build the artificial trachea before the patient succumbed to the cancer.

They began by sourcing a precise glass mold of the patient’s trachea based on 3D CT scans. This was then filled with a revolutionary new porous polymer – POSS-PCU – which went on to form a replacement organ.

The artificial trachea was left in a bioreactor filled with the patient’s stem cells. Over a period of days, the cells attached themselves to the porous polymer until a layer of tissue had formed. The trachea was then flown to the patient based in Sweden, where it was implanted during a 12 hour operation.

So far, the patient’s prognosis is very good. The organ has been accepted by the patient’s body due to its biocompatibility, which prevents it being seen as a foreign body. The flexible polymer is also functioning well. The patient can now breathe and cough independently. The patient was discharged from hospital less than a month after the operation.

While the polymer is already capable of replacing a range of tissues from arteries to tear ducts, the hope is that it could be used to create a large variety of organs, with heart parts planned for within five years. The polymer also has the potential to replace bones, opening new doors in fields ranging from hip replacements to reconstructive surgery. Cosmetic surgery too could benefit, with breast augmentation made safer by coating silicon implants with the polymer to prevent the chance of them bursting.

A form of the polymer is also under development that will help the body regenerate its own tissues. Much as with this transplant, the stem cells used with the organ will merge with those in the body building, around the artificial organ or tissue. Artificial organs made of the new material, however, will slowly biodegrade. When it does, what will remain will be an organic organ, ‘home grown’ and disease-free.

The new material is also a breakthrough for its price; the polymer is cheap, with 500ml of polymer – enough for two tracheas – costing around only £50. The new material will radically cut the cost of transplant surgery, eliminating both the cost of caring for donor organs and the expensive course of drugs that follow.

More artificial parts are planned for the near future, with a young Korean girl due to have part of her windpipe replaced later in the year. Given the success so far, a future where the construction of nearly any body part now seems much closer, and the days of donor organs seem numbered.