Disinfection in hospitals: textiles inhibit pathogens

Antimicrobial textiles can curb the spread of pathogens in hospitals. On the one hand, they reduce the amount of disinfection required by staff and, on the other, they increase the protection of patients against infection. Empa in Switzerland has tested the coating of curtains with antimicrobial substances in a study.

In an interview with MEDICA-tradefair.com, Prof. Peter Wick explains how a process for textile coating was developed together with the chemical company BASF and where and how it could be used if necessary.

Prof. Wick, what was the trigger for this study?

Prof. Peter Wick: During the pandemic, we experienced that the supply chain for protective and hygiene materials was interrupted. In such a case, our laboratory at Empa wanted to equip existing textiles with antimicrobials as simply as possible to bridge the gap.

How does the coating work?

Wick: We have achieved the coating of textiles with an antimicrobial solution developed by BASF using a roll-to-roll process. The textile runs through a container with the disinfectant solution, then the solution is evenly distributed with two rollers and excess liquid is squeezed out. The process is reproducible, with one to three passes we achieve a uniform coating.

The textile industry can adapt existing systems so that antimicrobial coatings can be applied relatively quickly. Fine-tuning must be carried out depending on the type of textile; the method works with synthetic and natural fibers. A reproducible result can be achieved by adjusting the dilution, throughput speed and contact pressure of the rollers. The substances are not chemically covalently bound but bind by drying. The coating is stable for at least six months if the textiles are stored in a dry and cool place.

For which other areas is the process suitable?

Wick: For us, hospital curtains were just one possible example of protection against pathogens. Hygiene experts in hospitals probably see additional applications in infectious diseases where coated textiles can be used sensibly.

It was important to us that the process guaranteed a minimum standard of stability. For example, we found that bending the fabrics or rubbing them lightly did not remove large quantities of the coating.

To demonstrate the safety of the coating, we assumed a simultaneous release of all applied substances as a worst-case scenario. We were able to rule out any irritation caused by interaction with healthy skin.

Contact with textiles only lasts for a few seconds. Even with an accumulation over a longer period of time, we arrive at exposure times of minutes or hours, which rules out an acute effect.

How did the collaboration with BASF and the other partners work out?

Wick: We have had a regular exchange between Empa and BASF here on site for a long time, with BASF's innovation scouts and with the research and development team. We work together on various EU projects and have concluded a framework agreement and a memorandum of understanding. We are actively seeking this cooperation in order to advance new products with BASF for application on the market.

The TU Berlin is involved through a doctoral student and his supervisor. We had a close exchange with the Spiez laboratory during the pandemic, especially for the antiviral activities, and have now been advised on the interpretation of the data.

Are there any plans for further development or for other products?

Wick: There are no further plans at the moment, but if supply chains are interrupted again, demand will certainly arise quickly.

In order to make the effort for the coating process, there must be a recognizable need. Then the specifications can be adopted to speed up production and shorten the trial-and-error phase. We can take over the analytics for the necessary adjustments and pass on our experience.