Soundbite molecules - hospital beds with a silver lining?
Simon Cotton, teacher at Uppingham School, takes a look at those compounds that find themselves in the news or relate to our everyday lives. In this issue: hospital beds with a silver lining?
Don't let the 'bedbugs' bite
How is the silver introduced into the fabrics?
This can be done by incorporating silver threads into the fabric before weaving, or by treating the fibres with a silver-based coating, or by impregnating a polymer mesh with silver, which is wrapped around the fibres during manufacture.
How do the silver compounds work?
As with many other heavy metals, silver, as its cation, kills bacteria, but without the acute toxicity associated with metals such as lead and mercury. Heavy metal ions bind readily to groups containing oxygen, nitrogen and sulfur atoms, as well as negatively charged groups such as phosphates and chlorides. Once absorbed by the bacterial cell silver ions can attack proteins containing these groups, eg the sulfur-containing thiol (-SH) group common in enzymes vital to the survival of bacteria. Silver will also attack fungi and viruses, the latter by inhibiting their proteins and by complexing with viral nucleic acids.
Have silver compounds been used like this before?
The germicidal and antimicrobial properties of silver and its compounds have been known for thousands of years and put to use in silverware, eg Holy Communion chalices.
Do silver compounds have other medicinal uses?
Silver-coated wound dressings have been used for some years. Recent research suggests that silver-based antimicrobial coatings for wounds may kill MRSA bacteria by interacting with bacterial membranes, as well as forming a barrier to prevent bacteria from entering the wound.