One of the biggest hopes for nanotechnology is the design of molecules to support living processes. Pictured here, tiny gold ‘nanorods’ cover the surface of red blood cells – a snapshot of biotechnology in action, fixed in time with a blue chemical agent. Each gold nanorod holds tiny ‘pockets’, called aptamers, filled with a blood thinning chemical called thrombin. Firing a laser at these harmless specks of gold causes them to melt just enough to release the thrombin, preventing blood from clotting. The process can be reversed by triggering the release of a different chemical which counteracts the thrombin, allowing the blood to clot naturally. Intravenous injections of chemicals like heparin are currently used all over the world to prevent dangerous blood clots after operations. In the future, nanotechnology could be used instead, with the advantage of controllable clotting at the flick of a laser switch.
Written by John Ankers
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