In certain cases, a weak electric current can accelerate the healing of wounds: various studies have been conducted in this regard, and there are several types of patches on the market in the United States that exploit this principle and that have been approved by the Food and Drug Administration (in technical terms these patches have been named: wireless electroceutical dressing, or WED). How do WED dressings work? In general, they contain silver and zinc within the fabric (gauzes and patches) that generate a weak electric field without any external supply source when the dressing is dampened, hence using the normal charges found in the cells (due to a complex series of physical and chemical laws). It was already known that WED dressings probably had an effect on the biofilm, namely the very thin layer of organic material that bacteria form to “protect themselves” and that in many cases prevents antibiotics from reaching their destination.
Now, however, a team from the University of Indiana (Ohio State, USA) has managed to clearly define the “mechanisms” of WED dressings, by examining their effect, using a scanning electron microscope, on the wounds of the skin of laboratory animals (pigs) contaminated with Pseudomonas aeruginosa and Acinetobacter baumannii bacteria. As reported in the scientific journal Annals of Surgery, the researchers monitored the wounds and discovered that, just two hours after the application of the WED devices, and then after one week (when, therefore, the biofilm has generally formed and is “solid”), there was no longer any trace of the barrier created normally by bacteria. To confirm this data, the researchers treated the same type of wounds also using traditional dressings (without weak electric currents), and they discovered that the effect of the WED dressing accelerated the healing process, which would usually be obstructed by the biofilm, whereas the infection proceeded undisturbed in the wounds treated using the traditional method.
The experts say that the current induced by the WED dressings probably interferes with the electric fields produced by the bacteria to communicate with one another and to create biofilms, mitigating or voiding their effect.
Other studies will be required, also on humans. If, however, this ability to slow down bacteria is proven, the dressings that use the weak electric currents could be applied, for example, to surgical instruments, or to devices such as catheters or prosthetic limbs, where biofilms thrive and constitute one of the main problems in the fight against hospital infections. According to the Centers for Disease Control of Atlanta (USA), biofilms are responsible for 65% of all the bacterial infections acquired as a result of a medical intervention, whereas according to the National Institute of Health this percentage reaches as much as 80%.
Source of the picture: The Ohio State University Wexner Medical Center