Heal Wounds With Electricity

Wounds can be healed up to 50% faster by controlling electric fields surrounding them.

"Scientists have found how the body harnesses the power of electricity to heal cuts and grazes - an effect they manipulated to speed up wound healing dramatically.

In what amounts to the modern rediscovery of an old medical curiosity, the finding raises hopes for revolutionary treatments to patch up injured patients in hours instead of days.

In preliminary lab tests, researchers showed that by controlling the weak electrical fields that arise naturally at wound sites, they could direct cells to either close or open up a wound at the flick of a switch. By making the cells move faster, they were able to speed up wound healing by 50%.

The role of electricity in wound healing has received scant attention from the scientific community since the German physiologist Emil Du Bois-Reymond cut his arm and measured the electrical field across the wound in the mid-1800s. But in the journal Nature today, an international team of scientists led by Aberdeen University not only confirms the effect but also unravels the genetic machinery behind it.

Using sheets of skin in dishes, Min Zhao and Colin McCaig show that electricity flows from the edges of a wound as soon as an incision is made. The current is triggered by positively charged sodium ions coursing through the tissue in one direction and an opposing rush of negatively charged chloride ions, together creating a voltage across the wound about 15 times weaker than an AA battery.

"These natural signals are instantaneous. The moment you make a wound, there's an electrical signal at the wound edge and it lasts as long as it takes the wound to heal up," said Professor McCaig.

Further tests showed epithelial cells, the building blocks of skin tissue, sensed and followed electric fields towards the wound site using two molecular structures, or receptors. One mobilises cells to creep in the direction of the electric field, while the other shuts down any signals that threaten to send the cell off course.

"They're stimulated to move, but they're also told where to find the centre of the wound, so these electrical signals are telling cells, 'get charging, get yourself in there'," Prof McCaig said.

The charge itself is far from rapid. Measurements of individual cells show they encroach on the wound at a speed of 50 micrometres an hour, the equivalent of just over one millimetre a day.

But tests on tissues and genetically modified mice show the healing mechanism can be speeded up by 50% by subjecting wounds to electrical fields or drugs such as prostaglandins that can boost the ability of cells to shunt ions around.

"We can increase the natural electrical signals using a variety of chemicals we'd apply to wounds, and by doing that we can get faster healing. What amazes me is that this has been relatively neglected for such a long time," said Prof McCaig."