The researchers say they have managed to reduce potentially harmful exposure to sliver nanoparticles by chemically binding the nanoparticles to polymers, making it more difficult for them to penetrate the skin’s surface.
The technology uses a rubber-like acrylate polymer containing a water-soluble block that enables the silver nanoparticles to be released from what is otherwise a hydrophobic coating.
Research has wide-reaching implications
Although the research has centered around coating materials used in products such as textiles, paints and flooring, the scientists say that its research is likely to have implications for a variety of products with added silver nanoparticles, including the colloidal silver used in the personal care category.
Colloidal silver solution is a water suspension of ionic silver or silver proteins, which is most commonly used as either an antibacterial or preservative in a range of soaps and creams and other medicated products.
In the past, the excessive ingestion of colloidal silver has led several people to develop argyria – a harmless condition that leaves victims with a pronounced gray tinge to their skin.
Fear of turning gray...
Subsequent media reports drawing attention to these rare cases of argyria has led to fears of toxicity on the part of consumers, which ultimately led the FDA to ban colloidal silver in over-the-counter medical products.
Although the substance can still be legally used in cosmetics products in the US, misinformation over toxicity means that the ingredient is often shunned by consumers, even though topical use of products containing recommended doses poses no risk.
Likewise, recent research into the effects of nanoparticles has demonstrated that they can penetrate mammal cells, which some scientists believe could ultimately damage the genotype.
Controlling nanotechnology
Although a lot more research has to carried out to determine the exact side effects of nanoparticles, research work such as this carried out by the Finnish team to stabilize nanoparticle-based technologies is becoming increasingly relevant.
The discovery by the Finnish scientists means that personal care products could potentially be formulated using colloidal silver without the associated risk of toxicity, while also reducing the risk of formulation volatility.
The full results from the team of scientists are due to be published in the forthcoming issue of the journal of Colloid and Polymer Science and is also available from the University of Helsinki.
Source: ‘Synthesis of copolymer-stabilized silver nanoparticles for coating materials’, The University of Helsinki.