How electrical stimulation works for the treatment of bacterial infections
The Washington State University researchers passed an electric current over a film of bacteria and in 24 hours killed almost all of a multi-drug resistant bacterium that is often present in difficult-to-treat infections. The remaining bacterial population was 1/10,000th of its original size. The researchers also tested the method on pig tissue, where it killed most of the bacteria and did not damage surrounding tissue.
Researchers have tried treating infected wounds with electrical stimulation for more than a century but with mixed results. For obvious reasons, antibiotics have been the preferred and most effective treatment for infections, but their widespread use has led to drug-resistant strains. In the U.S. at least two million infections and 23,000 deaths are attributable to antibiotic-resistant bacteria each year, according to the Centers for Disease Control.
Electrical stimulation has had mixed results against bacteria, but this is probably due in part because people didn't have a clear understanding of how it works electrochemically, said Haluk Beyenal, co-author of the paper and a professor in WSU's Gene and Linda Voiland School of Chemical Engineering and Bioengineering.
The WSU researchers for the first time demonstrated the electrochemical reaction produces hydrogen peroxide, an effective disinfectant, at the electrode surface. "We have been doing fundamental research on this for many years, and finally, we are able to transfer it to technology,'' said Beyenal. "It's really exciting.''
The researchers optimized the reaction and developed an "e-scaffold," a sort of electronic Band-Aid made out of conductive carbon fabric. By running electrical current through the fabric, they produced a low and constant concentration of hydrogen peroxide to kill the bugs. The bacteria are unable to develop resistance to such an electrochemical treatment. "Many people tried this simple method,'' said Beyenal. "Sometimes it worked, and sometimes it didn't. We controlled the electrochemical reactions. That's the reason it works.''
The researchers have applied for a patent and are now working to increase the e-scaffold's effectiveness and test it with a variety of bacterial species.
Source: Washington State University