PHOTOCATH · Self-disinfecting Photodynamic Catheters to Prevent Nosocomial Infections

Catheter-associated urinary infections (CAUTIs) are among the most common nosocomial infections, leading to substantial morbidity and mortality. They prolong hospital stays and significantly increase the economic cost of the disease. Despite the many techniques that have been developed to prevent them, spanning from the training of health professionals to the intraluminal use of antibiotics or ""classical"" microbicide coatings, the problem is still largely unsolved. A smart strategy to address the problem would be the development of a universal microbicide coating that only exercises its effect on the indwelling catheter when activated with visible light travelling through the catheter itself, the latter playing as a hollow optical fibre if made of transparent polymer. In this context, we aim to prepare self-disinfecting photoactive (urinary) catheters using the advanced components that modern chemistry and technology provide us, namely, (i) low-power super-bright cheap LEDs and laser diodes, (ii) highly transparent biocompatible polymers (silicones), (iii) versatile surface functionalisation techniques (plasma, silanisation) and (iv) tailored photosensitising dyes capable of generating large amounts of singlet oxygen upon illumination. This reactive oxygen species leads to the destruction of the microorganisms and, therefore, the incipient biofilm (antimicrobial photodynamic inactivation, aPDI), leaving unharmed any cell not contacting the catheter. The combination of the researcher knowledge (photochemistry, dye derivatisation and photodynamic effect), and some of the strongest areas of expertise within the host groups and collaborators (applied photonics, silicones and microbiology), provides all the necessary tools to tackle this challenging interdisciplinary proposal. The project success will benefit both the researchers involved and the entire society, as it contributes to overcome the problem of CAUTIs occurring in hospitals and long-term care facilities.""