Monday, February 23, 2015

Nano Gold-A new approach to fight bad bacteria!

Gold is supposed to be in great demand globally because of its high value per se and the use it has for making jewelry items. A country like India boasts of a rich stock of gold in the form of jewelry hoarded by millions of families for wearing on festive occasions and as a tool of financial security and insurance against inflation. Industrially also gold is a valued material used in many electric contact applications and other special purpose applications by the industry. Of the 4000 tons of gold produced last year more than 50% is consumed by two countries-China and India. Interestingly Chinese use it for industrial applications while in India gold is largely consumed for jewelry. According to one estimate each cell phone produced has about 50 mg gold used for corrosion proof electric contacts. A new application just reported for gold relates to making nano particles from it for deploying against virulent bacteria and control infectious diseases. It was known that heavy metals like Silver, Copper and its alloys exert what is known as oligodynamic action on bacteria to kill them fast. Food and pharmaceutical industries make use of this property to disinfect water and other products and make them safer. However action of gold nano particles for antibacterial application is a new finding which may excite the industry as gold has a better credential as far as consumer safety is concerned. Read further below to understand the real implications of these findings.

"We've been hearing a lot about the antibacterial qualities of silver, with silver nanoparticles finding use in everything from water filters to food packaging. Unfortunately, there are also concerns about the toxicity of those particles, particularly when they enter our bodies. Now, however, Polish scientists have developed what they claim is a safer alternative -an antibacterial coating that kills microbes using gold. Developed at the Institute of Physical Chemistry of the Polish Academy of Sciences in Warsaw, the coating can reportedly be applied to a wide variety of surfaces. It's said to be very chemically stable, and is able to withstand repeated washings with antibacterial coating that kills microbes using gold. Developed at the Institute of Physical Chemistry of the Polish Academy of Sciences in Warsaw, the coating can reportedly be applied to a wide variety of surfaces. It's said to be very chemically stable, and is able to withstand repeated washings with detergent.The coating initially takes the form of liquid boron compounds which contain colloidal gold nanoparticles. The object to be coated is immersed in the solution, and a polymerizing agent is then added. This causes the liquid to form into a nanocomposite polymer, coating the surface of the object within about 12 minutes. In lab tests, populations of E. coli and Staph. aureus bacteria decreased by up to 90 percent within 12 hours of exposure to the nanocomposite. Unlike some other antibacterial coatings, however, this one doesn't kill bacteria by releasing anything into their environment. Instead, the gold nanoparticles stay put, and only affect microbes that come into direct contact with them. Not only is this quality claimed to make the coating safer for people and the environment, but it should also allow it to remain effective for longer.Additionally, the nanocomposite so far appears to be harmless to human cells. After being exposed to it for several months, four lines of human cells reportedly remained unharmed. In fact, cells even started growing on cotton wool fibers treated with it.It is hoped that once developed further, the coating could be used on things like wound dressings and other medical applications, along with consumer goods such as sportswear, socks and underwear". 

While such findings are nice to hear, what about the cost factor? Gold is more than 10 times the cost of silver and can industry afford to use it instead of gold? There appears to be an edge for gold over silver in that silver nano particles are not yet cleared for safety in human products because of its likely toxicity in the cells. Silver and copper are known to react with the enzymes like Lactate Dehydrogenase and Glutathione peroxidase, two vital enzymes in the cells necessary for metabolism. But gold is said to be free from such undesirable reactions though it is not yet established conclusively. A little known fact about silver is that it is ineffective against virus infection though it is not clear whether gold also suffers from this handicap. Historically the world had produced so far about 1.74 lakh tons of gold, most of which have been locked up in the vaults of various countries for ensuring their economic security and in millions of households in India as jewelry items, not put to effective use for the well being of human beings. If the present research bears fruition, at least gold may find a use for a noble cause.     .   


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