Mean spikes fight microbes

Whether it’s toilet lids or medical exam tables: hospitals and medical offices have many surfaces that must be kept sanitary and clean at all times. A variety of cleaning products and coatings are effective ways to keep these settings clean.

In this COMPAMED-tradefair.com interview, Oliver Sonntag from Nano-Care Deutschland AG introduces a particularly "mean" coating.  It literally impales bacteria and viruses and renders them harmless.

Mr. Sonntag, your company developed an antimicrobial coating that uses nanotechnology. How does it work?

Oliver Sonntag: Unlike biocides with silver ion technology that disrupt the microbial metabolism, Liquid Guard uses physical effects. The liquid allows us to create a structure of super-sharp molecules on the treated surface, causing the microorganisms to rupture their cell walls and burst. This physical effect offers several advantages. It delivers a permanent antimicrobial function that lasts. We also don’t disrupt and interfere with the microbial metabolism and thus avoid mutations. After all, there is a risk of antimicrobial resistance after several mutations if the cell is destroyed via biochemical reactions. That’s also the reason why certain substances such as triclosan have been banned by the U.S. Food and Drug Administration (FDA). Meanwhile, a physical effect does not cause microorganisms to mutate.

How often should you reapply the protection?

Sonntag: That depends on how often the treated surface is being used. The coating of a toilet lid that is cleaned daily or doorknobs that are touched multiple times a day should be reapplied after about a year. Other surfaces that are not subject to increased abrasion can be retreated at longer intervals.

Where can this coating be applied?

Sonntag: You can use it anywhere, though there are still regulatory concerns in the field of medicine and medical technology. The product would need to be approved as a medical device first before you can directly apply it to any other medical devices right at the factory. We are currently in the process of obtaining this approval. Having said that, registration as a biocidal product is sufficient for use in the hospital environment or on surfaces that come into contact with a patient’s skin. We aim to obtain the recommendation for hospital use in 2019 and will start talks with the Robert Koch Institute in February.

Which certifications does the product currently have?

Sonntag: It can be marketed and used as a biocidal product in Germany. We also want to register in most of the 27 other EU countries. Subjects also rated our product as "excellent" in a skin patch test. The test included 30 students, who applied plastic sheets coated with Liquid Guard on their backs for 72 hours. An independent testing laboratory tested an accelerated aging protocol of the coating under ASTM F1980 to prove longevity and integrity of the product. The result: 99.99 percent reduction in germs even after a simulated aging period of one year. We are currently also pleased to announce that our product was nominated for the 2019 German Innovation Award.

Does the antimicrobial coating have to be applied by an expert or can this also be done by a non-specialist?

Sonntag: Anyone can apply the coating. You have the option of ordering the product as a liquid or wet wipe. The wipes are individually wrapped, allowing users to directly apply the coating after removal. The coating is wiped on in a very simple process. The surface is available for use after only 6 hours.

Are there pathogens that are resistant to this coating?

Sonntag: We have not detected any so far. We have successfully tested both gram-positive and gram-negative microorganisms. That is to say, more than 99.9 percent of microorganisms were rendered harmless. The Japanese standard JIS Z 2801: 2012 refers to this as a “total kill”. This is a difficult test with a very high number of germs being adhered to the surface. In doing so, we were able to prove that our antimicrobial coating is effective even if it is subjected to a large number of colony-forming units (CFU).