Silver Bullet

Nanoparticles of the metal can prevent blood clots

Blood clots are a common cause of heart attacks, strokes and coronary arterial diseases. Clots block arteries, choke blood and oxygen supply to tissues, thus killing them. The way to deal with this is to take anticoagulants, like aspirin and heparin, which thin the blood. But in large doses they can cause excessive bleeding. However, sedentary lifestyle and high incidences of these diseases have increased the use of such drugs.

Siddhartha Shrivastava and his colleagues at the department of biochemistry, Banaras Hindu University, Varanasi, have found an alternative to these drugs. They have used ultra fine silver particles called nanoparticles to inhibit platelets, cells that aggregate to form clots. Nanoparticles can have a diameter as small as a billionth of a metre.

Usually, nanoparticles are used to deliver medicines, in the proper doses, to specific tissues. But silver nanoparticles have the innate property of inhibiting platelets. Shrivastava's experiment showed over 80 per cent inhibition of platelet activity in tissues injected with nanoparticles at high concentrations. At the same concentration, the inhibition of platelet activity in diabetes patients not dependent on insulin was 50 per cent, found the study published in the June 23 issue of ACS Nano.

Since nanoparticles act on targeted tissues, there is no risk of bleeding. But overexposure to nanosilver can lead to toxicity in the liver, spleen, lungs and kidneys.


Down To Earth, July 2009