Shocking news about chlorhexidine

There is some evidence that passing electricity through a biocide enhances its biocidal activity – a so-called ‘bioelectric effect’. At the molecular level, biocidal activity depends on some sort of chemical interaction at a molecular level. Things tend to happen more quickly in chemical reactions when you add more energy – to a point. And it is likely to be the same with electricity added to a biocidal chemical reaction.   And so it is perhaps no surprise that a team of researchers from Belgium found that Porphyromonas gingivalis (an important organism in dentistry) biofilms were inactivated further by chlorhexidine when a 10mA current was run through them. The effect was not identified when a 1.5mA current was used, and the effect was actually fairly modest even with the 10mA current (87% vs 99% reduction, around a 1-log difference).   Assuming there is a measurable ‘bioelectric effect’ associated with chlorhexidine, how could this benefit be realised in practice? It’s perhaps possible to introduce a low electric current into specific points of the mouth during dental treatment, but the skin is a lot more tricky. Believe it or not, applying an electric current to the skin is used as a way to improve drug delivery, so perhaps the idea isn’t a far-fetched as it may seem!   Chlorhexidine is an excellent biocide, but its effectiveness is reduced by biofilms (as is the case for all biocides) and Gram-negative bacteria are relatively less susceptible to chlorhexidine than Gram-positive bacteria in laboratory studies. Electrifying the skin therefore, terrifying as it may sound, could be a way to help to address these challenges!