Oxygen under Pressure Increases Effect of Antimicrobial Agents

New research from DTU will extend the life expectancy of chronic patients with cystic fibrosis, and delay the need to replace artificial hips and knees.

antimicrobial

n collaboration with Rigshospitalet and the University of Copenhagen, Associate Professor Thomas Sams, the Biomedical Engineering group at DTU Electrical Engineering, has completed a number of laboratory trials on the effect of antimicrobial agents on biofilms. Biofilms reside in the ‘goo’ formed in the body in connection with inflammation—which we all know from wounds on knees, hands etc.

“Inflammation is normally combated by the body’s immune system. But biofilms become permanent for some patients—and must therefore be combated using antimicrobial agents. This applies, for example, to patients with cystic fibrosis, whose lungs are unable to cleanse themselves. In connection with the implantation of artificial hips, knees, teeth etc, biofilms also form over time on the surface of the implant, which the body is unable to fight,” explains Thomas Sams.

Antimicrobial agents work better with oxygen and pressure

The research was the result of collaboration between Associate Professor Thomas Sams and Kaj-Åge Henneberg, DTU Electrical Engineering, and Peter Østrup Jensen and Mette Kolpen from Rigshospitalet and the University of Copenhagen. The researchers have completed a number of laboratory tests to gain knowledge of how well the different types of antimicrobial agents are absorbed in the biofilm—and can thus help fight the bacteria.

The trials have included the addition of a third substance to investigate whether it promotes absorption. They found that treatment using antimicrobial agents has a greater effect if it is combined with pure oxygen and pressure. This is presumably because some antimicrobial agents work best in connection with cell division in the biofilm, which can be promoted through oxygen treatment.

“We have not yet worked out the best timing for the treatments. At the moment, it appears that it is ideal if the patients receive oxygen treatment an hour before taking the antimicrobial agents. But we need to complete a more detailed investigation before we can say anything definitive,” says Thomas Sams.

“The effect of exposing the patient to pressure should also be further examined. This is more complicated, however, as it prevents prompt action from the healthcare professionals if the patient suffers ill effects during the treatment. You cannot just pull someone out of a pressure chamber with a pressure corresponding to diving at 18 metres’ depth.”

The new research is important as it can help extend the life of patients with cystic fibrosis by several years—and the life time of artificial implants can also be increased. This means it will be longer before patients have to undergo surgery again, for example to receive a new artificial hip.