There could be new hope in the fight against hospital-acquired infections. Spanish scientists have developed an experimental type of self-disinfecting cotton fabric, which is activated via ordinary white light.
In their weakened state, hospital patients are particularly vulnerable to infection not only by viruses, but also by microbes such as bacteria and fungi.
We've previously heard about light-activated materials that could be used to neutralize such pathogens in clinical settings, although those substances have typically required special types of light – blue light or ultraviolet light, for instance. By contrast, the new fabric utilizes the visible white light that's already being used in hospitals.
Developed by a team of scientists at the Universitat Politècnica de València (UPV), the fabric combines a base of regular cotton with layers of chitosan and a crystalline chemical compound known as cyanoguanidine. Those layers are impregnated with two photosensitive antimicrobial dyes: methylene blue and rose bengal.
In lab tests, when exposed to white light, the fabric completely inactivated Escherichia coli bacteria within 60 minutes and Enterococcus faecalis within 20 minutes. The material additionally achieved a significant reduction in Candida albicans fungus within three hours.
Taking things a step further, the fabric was then tested in the rooms of 12 patients at La Fe University and Polytechnic Hospital in Valencia. Pieces of it were placed on the bed rails – where they received direct light – and on the mattresses – where they received less light – for 48 hours. Untreated cotton samples were placed in those same locations as controls.
"In the hospital rooms, the fabric exposed to light accumulated 75% fewer microorganisms than a conventional cotton fabric placed under the same conditions. When the material was placed in an area without direct light, the reduction was much lower, just 25%, confirming that its antimicrobial effect depends largely on lighting," says team member Inmaculada Andreu. "The efficacy was particularly high against gram-positive bacteria, with their presence reduced by 77.5%."
Importantly, the fabric retained much of its antimicrobial effect even after 20 wash cycles. And the scientists state that the manufacturing process could be easily integrated into standard textile-finishing techniques.
A paper on the research was recently published in the journal ACS Applied Materials & Interfaces.