Antibacterial coatings

Important ingredient in fighting infection rather than a panacea, says Andrew Jones

Reducing the levels of bacteria has been key in combating disease and illness for centuries, but is now reaching truly innovative levels of use in our lives.

Along with sterilisation equipment and solutions, anti-bacterial coatings are now becoming commonplace because even the most mundane inorganic object (such as a keyboard or smartphone) can harbour potentially dangerous microbes. However, there appears to be a worryingly popular misconception that these technologies in isolation will prevent disease transportation.

Ever since Dutch scientist Antonie van Leeuwenhoek first witnessed the existence of bacteria via a microscope, medical science has strived to protect the human race against the ill effects of bacteria. With the environment around us literally awash with micro-organisms, many anti-bacteria systems concentrate on limiting the contact these potentially dangerous microbes have with vulnerable people, animals or items that may come into contact with them.

For obvious reasons medical establishments and facilities are particularly interested in anti-bacterial options - to a far greater degree than in wider society.

As well as protecting vulnerable patients against common environmental microbes, medical facilities also look to limit the spread of contagious organisms which can thrive amongst those with compromised health. When faced with this level of scrutiny over cleanliness it’s easy to see why anti-bacterial coatings have gained such wide attention and demand.

As a communications developer and manufacturer, with long-standing ties to the medical industry, Multitone is acutely aware that these items can be as much a potential host for infection as any other. We introduced anti-bacterial plastics to our pagers some time ago. It is, we believe, an important addition to any product aimed at medical professionals. However, it’s equally important to realise they need to be a part of a much broader cleanliness regime, rather than a solution in themselves.

Anti-bacterial plastics offer very good first contact protection. Laboratory Tests carried out on behalf of Multitone on our own items showed that within 12 hours the levels of S.aureus and E.coli had been reduced by 99.8%.

However, these surfaces will eventually be compromised by the very dead bacteria themselves. Anti-bacterial surfaces are only effective for a finite amount of time. Inevitably the surface will need to be cleaned thoroughly on a regular basis to ensure effectiveness is maintained.

There are other potential issues to consider too. When used in a busy environment the surface can become cracked or scratched, providing a haven for bacterial growth. The way in which items are cleaned is significant in keeping devices sterile.

A cleaning spray, or bath, are common ways re-sterilise a device, but they lead to the possibility of liquid ingress to the product and so it needs designing from the beginning with anti- bacterial properties in mind.

In the first instance unnecessary grooves and designed indents need to be removed. Labels are a breeding ground for bugs and should be omitted from any anti-bacterial design. There is then the issue of what is being used to clean a device and how this reacts with the device materials. Soft spongy surfaces collect dirt and liquid so should be avoided which can restrict the design options for the creative designer.

So which devices can be designed and built to reject bacteria? Collection of dust, for even a short period of time can render them effectively useless. Many organisations are now dipping a device in anti-bacterial solution or spraying, once a day. This, while only killing the bacteria present, allows the anti- bacterial plastic of the device to do it's work throughout the day, killing germs as they land on the device.

This has influenced the way in which Multitone designs its health sector targeted devices. For instance, we aim to limit the use of removable battery casings because the handles and interior of the hatch could potentially harbour dangerous bacteria.

The spread of highly contagious pathogen diseases such as MRSA are a big concern for health authorities. Figures from the UK’s Office of National Statistics suggest that 13% of deaths where MRSA is mentioned in the death certificate, identify the organism as the underlying cause of death. Awareness and prevention of infection have been a key factor in reducing risk (statistics show MRSA deaths decreased by 79% in males and 76% in females between 2008 and 2012 when improved cleaning regimes were introduced) but it is vital that cleanliness regimes are maintained as a whole, rather than relying on isolated technology such as anti-bacterial coatings.

Where anti-bacterial materials have become very useful, is in helping devices stay clean once cleaned thoroughly. Chemical sprays and sterilisation methods are not inherently kind to electronic equipment, but the price of not being clean may be much higher. With this in mind, Multitone's medical-focussed products have inbuilt and thoroughly designed water ingress tolerant properties to ensure they can withstand cleaning. Anti-bacterial coatings mean that the exterior casings take less effort to return to acceptable levels of cleanliness and help to extend the lifespan of these technology investments.

Overall anti-bacterial materials are a very useful and powerful contributory benefit to any strict cleaning regime. However, the ferocity and danger of many infectious microbes means that thorough cleaning is still the vital part of the war against infection. Complete cleanliness processes are needed to ensure that even non health related items such as communications equipment are still sterilised on a regular basis. Undoubtedly, inbuilt antibody designs have an important part to play, but only as part of the much wider enforcement of measures which will protect the most vulnerable from infection.

Andrew Jones is Marketing Manager at Multitone

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