Alternative to antibiotics
Plasmas attack bacterial cells on several levels
RUB researchers analyse the mechanism of action of UV photons and radicals
Plasmas affect cell envelope, DNA and proteins
Depending on their specific composition, plasmas may contain different components, for example ions, radicals or light in the ultraviolet spectrum, so-called UV photons. Until now, scientists have not understood which components of the complex mixture contribute to which extent to the antibacterial effect. Julia Bandow’s team has analysed the effect of UV photons and reactive particles, namely radicals and ozone, on both the cellular level and on the level of single biomolecules, namely DNA and proteins. On the cellular level, the reactive particles alone were most effective: they destroyed the cell envelope. On the molecular level, both plasma components were effective. Both UV radiation and reactive particles damaged the DNA; in addition, the reactive particles inactivated proteins.
No effective antibiotics in ten years’ time?
Atmospheric-pressure plasmas are already being used as surgical tools, for example in nasal and intestinal polyp extraction. Their properties as disinfectants may also be of interest with regard to medical applications. “In ten years, bacteria might have developed resistance against all antibiotics that are available to us today,” says Julia Bandow. Without antibiotics, surgery would become impossible due to high infection rates.
J.-W. Lackmann, S. Schneider, E. Edengeiser, F. Jarzina, S. Brinckmann, E. Steinborn, M. Havenith, J. Benedikt, J.E. Bandow (2013): Photons and particles emitted from cold atmospheric-pressure plasma inactivate bacteria and biomolecules independently and synergistically, Journal of the Royal Society Interface, DOI: 10.1098/rsif.2013.0591