In hospital tests, cotton cuts germs 75% under white light

Weakened patients are vulnerable to more than viruses: bacteria and fungi find their way to them too, and the cotton in a hospital room is never far away. A team at the Universitat Politècnica de València (UPV), in Spain, has built a cotton fabric that fights those microbes using the white light already switched on in hospitals.

The fabric starts from ordinary cotton, covered with layers of chitosan and a crystalline chemical compound called cyanoguanidine. Those layers are impregnated with two photosensitive antimicrobial dyes, methylene blue and rose bengal. Other light-activated materials have typically needed blue or ultraviolet light. This one works with visible white light, which is the kind already used in clinical settings.

In the lab, the results were strong on some germs and weaker on others. The fabric completely inactivated Escherichia coli within 60 minutes and Enterococcus faecalis within 20 minutes. It achieved a significant reduction in the Candida albicans fungus within three hours. The team also reported an efficacy of 77.5% against gram-positive bacteria.

The next step was a real hospital room. Pieces of the fabric were tested for 48 hours in the rooms of 12 patients at La Fe University and Polytechnic Hospital in Valencia, placed on bed rails where they received direct light and on mattresses where they received less. Untreated cotton was placed in the same spots as a control. Team member Inmaculada Andreu says that the fabric exposed to light "accumulated 75% fewer microorganisms than a conventional cotton fabric placed under the same conditions". Without direct light, the reduction was just 25%, which confirms that the effect depends largely on lighting.

For patients and hospital staff, the appeal is a textile that keeps working during daily use: the fabric retained much of its antimicrobial effect after 20 wash cycles, and the scientists say the manufacturing process could be easily integrated into standard textile-finishing techniques. The sources give no date for hospital use, no price, and no figures beyond these trials. The strongest numbers come from laboratory tests, and the hospital evidence covers 12 rooms over two days, so the next step is reproducing these results over longer periods and in more settings. The study was published in ACS Applied Materials & Interfaces.