29 September 2008

“A man-made artery that behaves just like the real thing could transform heart bypass surgery. The British invention looks like a piece of spaghetti and is coated with a space-age that stops it from becoming blocked once it has been implanted.”

“Previous attempts to manufacture synthetic arteries have been hampered by the fact that they quickly became clogged. The body recognises them as foreign and and, thinking it has suffered an injury, dispatches special blood cells called platelets. Their job is to trigger the clotting process to halt bleeding. As platelets clump together inside the implant, blood fails to flow properly, increasing pressure on the heart. But the high-tech, man-made artery gets around that problem thanks to its unique coating.

“The inside of the device is layered with tiny ‘cages’ made up of millions of tiny molecules. These cages are so small they cannot be felt or seen by the naked eye. But under the microscope they look like tiny spikes sticking out into the man-made graft. The entire structure is coated with chemicals that attract stem cells in the blood and stimulate them to start growing into exactly the same kind of cells that form the lining of the healthy human blood vessels. Within a few days, enough stem cells are caught to start covering the whole inside of the man-made artery with a smooth, healthy lining, called the endothelium. The beauty of the technique, a winner in the recent Medical Futures Innovation awards, is that this makes the artificial blood vessels elastic and stretchy, just like the ones we are born with, and the smooth new lining stops clots from forming.

“So far it has been tested only on animals, but two years after being implanted into a sheep, it is still functioning perfectly well. Human trials on the implant, developed by scientists at University College London, are expected to begin within the next year. Dozens of patients whose coronary arteries are more than 70 per cent blocked because of heart disease will be fitted with the new ‘spaghetti’ implant.

“Patients with severely diseased arteries often undergo a procedure called a coronary artery bypass graft. About 28,000 bypasses are carried out in the UK each year – here, blockages in the heart are ‘bypassed’, usually using a vein from another part of the body. Professor Alexander Seifalian, who pioneered the new man-made artery, said up to 30 per cent of bypass patients do not have a suitable vein they can use: ‘In these cases, there’s not much doctors can do and patients often die. So we have developed an artificial artery using nanotechnology. Once the stem cells are attracted into it, they cover the whole inside of it and turn into endothelial cells. The job of the endothelium is to stop things sticking to the inside of the artery. We hope this will eventually replace the need to take veins from other parts of the body,” he says.

Article reproduced courtesy of The Daily Mail newspaper.
Original publication date 31st July 2007

Further Information
For further information contact Karen Cheetham,
Project Liaison Manager, UCL Business PLC on 020 7679 9000 or k.cheetham@uclb.com