antibacterial property of silver has been known
for thousands of years with the ancient Greeks
cooking from silver pots, when eating from silver
vessels or with a silver spoon was known to
be more hygienic.
Manufacturing entire objects from pure silver metal or coating them with silver is prohibitively expensive for consumer items. However, research has found that impregnating other materials with silver nanoparticles is a practical way to exploit the germ fighting properties of silver. The extremely small size of nanoparticles means they exhibit enhanced or different properties when compared with the bulk material. The extremely small size of nanoparticles results in the particles having a large surface area relative to their volume. In the case of silver nanoparticles this allows them to easily interact with other particles and increases their antibacterial efficiency. This effect can be so great that one gram of silver nanoparticles is all that is required to give antibacterial properties to hundreds of square meter of substrate. Products made with silver nanoparticles have been approved by a range of accredited bodies, including the U.S. FDA, U.S. EPA, SIAA of Japan, Korea 's Testing and Research Institute for Chemical Industry and FITI Testing & Research Institute.
All bacteria use an enzyme as a form of ‘chemical lung' in order to metabolize oxygen. Silver ions cripple the enzyme and stop the take up of oxygen. This effectively suffocates any bacteria, killing it within 6 minutes and leaving surrounding tissue or material unaffected.
Viruses grow by taking over another living cell and reprogramming the nucleus to replicate the virus rather than the healthy cell. As part of this process, the cell reverts to a more primitive form that relies upon a primitive form of oxygen metabolizing enzyme as a chemical lung. Again the silver ions stop oxygen being brought into the virus-producing cell and it dies by suffocation.
A fungus is composed of a series of single cells. Each cell survives by means of a ‘chemical lung' much like that seen in bacteria. Just like bacteria, the presence of silver ions disables the chemical lung and the fungus dies.
Antibiotic drugs can be used to kill the pathogens
attacked by silver nanoparticles but bacteria
and viruses are becoming increasingly resistant
to drug therapies. Silver nanoparticles kill
all types of fungal infections, bacteria and
viruses, including antibiotic resistant strains.
No drug based antibiotic is effective on all
types of bacteria. Additionally, research has
shown that bacteria have been unable to develop
any immunity to silver. Elemental silver occurs
naturally. It is considered non-toxic, non-allergic,
is not cumulative and is not known to harm either
wildlife or the environment.
Major consumer goods manufacturers already
produce household items that utilize the antibacterial
properties of silver nanoparticles. These products
include nano-silver lined refrigerators, air
conditioners and washing machines. Other current
applications for silver nanoparticle impregnated