Infection-free hospitals: a step closer

1 November 2011

Odine hospital

UCL is leading the development of a major class of new medical devices. Translating innovative science into patient benefit, novel antibacterial materials could herald impressive reductions in hospital-acquired infections.

Hospital-acquired infections cost UK hospitals an estimated £1 billion and are linked to 8000 deaths each year.[i] But collaborations between UCL and industry are bringing us a step closer to saving lives and saving money.

Professor Ivan Parkin, Head of the Department of Chemistry, UCL and Professor Michael Wilson, Professor of Microbiology, UCL Eastman Dental Institute, are leading their teams in the development of new light-activated antimicrobial agents. These are embedded into films that can be used to coat surfaces in hospitals and reduce the spread of infection.

The technology

When light activates the new antimicrobial molecules, it puts photosensitive chemicals into their excited state. When the chemical relaxes back to ground state, it generates reactive oxygen species, including oxygen radicals and singlet oxygen. It’s these that kill the bacteria.

Reactive oxygen species damage bacterial cells more than human cells, making the method safe to use in people.

Unlike some other photosensitive chemicals, the technology works with white light rather than UV and will function indoors with standard room lighting.

Battling superbugs

One in ten patients who go into hospital picks up an infection there –a hospital-acquired infection – including ‘superbugs’ MRSA and C. difficile.

The main reservoirs of bacteria are telephones, computer keyboards, lift buttons and bed rails, so covering these with an antibacterial film could significantly reduce infection rates. Tests with novel antimicrobial surfaces have been promising: half an hour after exposing them to light, over 99.9% of bacteria had been eradicated.

Professor Parkin said, “Unlike antibiotics, reactive oxygen species work in a non-specific manner, damaging bacteria in hundreds of ways at the same time. This means they work on all types of bacteria. There’s also less risk of bacteria becoming resistant.”

With an MRC grant of £1m, the teams are also developing an antimicrobial catheter by embedding the light-sensitive chemicals into a polymer. Catheter-related urinary infections make up about 70% of hospital-acquired infections, so patients stand to benefit enormously from an infection-fighting catheter.

Industry links

For over ten years UCL has worked in partnership with biomedical company Ondine on photodynamic technologies. Together they developed Periowave photodisinfection system, a light- activated antimicrobial treatment for gum disease.

UCL Business supports their endeavor. Derek Reay, Senior Business Manager of UCLB said, “Combining applied research with industry has proven to be very effective for product development. We look forward to working with Ondine on the catheter as well as future projects that address antibiotic resistant pathogens.”

Student involvement

Students and post doctorates are involved with antimicrobial research at many levels. An engineering doctorate programme runs alongside the catheter research, which helps students gain valuable transferable skills such as project management, as well as scientific expertise.

Professor Parkin said, “I’m really keen to promote entrepreneurial skills in students and 3rd strand activities [the name for other outputs from the university than research or teaching]. There’s a real thirst for it.”

[i] http://www.medicine.ox.ac.uk/bandolier/booth/Risk/HAI.html, accessed 31 January 2010