Silver for external use

History

The positive effects of silver have been used in everyday life for a long time, even if people in earlier times were not even aware of its bactericidal effect. Silver containers were already used in ancient times to keep water or wine fresh. For example, the Persian king Cyrus (601-530 BC) had the water reserves for his army transported in silver jugs during war. Our great-grandparents also appreciated the precious metal: They put a silver coin in the milk jug to prolong the shelf life of milk.
Silver has always played a special role in the treatment of wounds: Traditions from ancient Egypt mention silver foils that were used to cover wounds and Hippocrates is said to have recommended silver powder for treating ulcers. Silver compounds were also an important weapon in the fight against wound infections during the First World War. Silver wires and plates were used to stabilise bone injuries and silver nitrate compounds have been used to treat wounds since the 18th century.

For a long time, silver sulphadiazine was considered the standard treatment for severe burns and is still used today.
With the discovery of penicillin, the first antibiotic, silver was gradually forgotten as an antibacterial agent. Due to the problem of the increasing number of multi-resistant pathogens that can no longer be combated with conventional antibiotics, the use of silver in the medical field has regained importance.

Areas of application

The positive antimicrobial properties of silver are utilised in many different ways today: Door handles, fridges and hygiene articles are coated with silver in certain areas and silver particles are incorporated into functional clothing. Due to its broad antimicrobial effect, which also extends to multi-resistant germs, the use of silver in medicine has been experiencing a renaissance for years in wound dressings and coatings for catheters and implants.

How silver works

The so-called oligodynamic effect of some metals, which is particularly pronounced in silver, is responsible for the bactericidal effect. Although silver is a precious metal that is chemically very stable and hardly reacts with oxygen, silver ions are released on contact with moisture, which attack the bacteria in various ways. Silver ions have the ability to bind to different structures of the bacterial cell (cell membrane, enzymes, DNA) and hinder their vital respiratory chain and cell division.

As the points of attack for silver are so wide-ranging, the effect extends to a large number of different bacteria as well as fungi. Resistance to silver is still virtually unknown, meaning that silver is also effective against multi-resistant germs such as MRSA.

Silver forms

In addition to silver salts such as silver nitrate and silver sulphadiazine (the silver salt of a sulphonamide), elemental silver is used in various particle sizes. Large, visible structures are, for example, silver threads or wires. Microsilver or much smaller nanosilver is used as small silver particles that are only visible under a microscope.

Microsilver

One way of safely utilising the positive effects of silver is the external application of so-called microsilver: With an average particle size of approx. 10 μm (=10,000 nm), microsilver particles are at least 100 times larger than nanosilver particles. Absorption through the skin is therefore impossible. This makes the external application of silver very safe, as silver is well tolerated by the external skin itself.
Due to a special sponge-like structure, the particles have a significantly larger surface area than those in conventional silver powder. On contact with liquid, enough silver ions can therefore be formed even at low silver concentrations to achieve an effective bactericidal effect.
Applied externally in low concentrations, microsilver is harmless to humans and animals and does not cause any irritation even on previously damaged skin.

Since microsilver does not penetrate the skin due to its particle size, it cannot accumulate in the body, so there is no risk of organ or nerve damage. The safe use of microsilver applied externally to the skin has been proven in several studies.

Tip:

If animals ingest small amounts of microsilver by licking them, this is harmless. However, the intake of large amounts of silver should be avoided if possible. It therefore makes sense to have products that are specifically tailored to animals and contain bitter substances that prevent oral absorption through licking.