Treating scars after burns with pulsed electric fields in the rat model.

Reducing scar size after severe burn injuries is an important and challenging medical, technology and social problem. We have developed a battery-powered pulsed electric field (PEF) device and surface needle electrode applicator to deliver pulsed electric fields to the healing dorsal burn wound in rats. PEF was used to treat residual burn wounds caused by metal contact in rats starting 10 days after the injury for 4 months every 11 or 22 days for 4 months using varying time applied voltages at 250-350V range, 400mA current, 40 pulses, 70 μs duration each, delivered at pulse repetition frequency 10 Hz at 5 locations inside the wound. We found 40-45% reduction in the scar size in comparison with untreated controls in both upper and lower dorsal locations on rats' backs two months after the last PEF application. We have not detected significant histopathological differences in the center of the scars besides the thickness of the newly generated epidermis, which was thicker in the PEF treated group.We showed that minimally invasively applied pulsed electric fields through needle electrodes are effective method and device for treating residual burn wounds in the rat model, reducing the size of the resulting scars, without any adverse reaction.