The Primary Results of the N₂/Ar Micro-plasma Exposure on Second Degree Wound Healing

Abstract

Second degree burn may reach the epidermis and partial dermis layers. Several methods and techniques have been applied to manage such burn injuries, such as different kinds of dressings, pharmacotherapies and plasma treatment. The latter has been increasingly studied. In this work, non-thermal N2/Ar micro-plasma was applied to enhance healing on the second degree burn wound mice through the wound area reduction. Four wounds were created in the dorsal of each mouse by solid aluminum bar with 5 mm in diameter (46g) and an average temperature of 69 ± 2°C. The parameters for micro-plasma exposure for burn wound on mice were chosen: excitation at 13 W (< 40 °C) and addition of 0.5% N₂ in Ar, corresponding with relatively high NO peak intensity.

N₂/Ar micro-plasma was utilized to expose upon the burn wound achieved mice in these groups: continuous exposure until 2 day wound (dw) (denoted as P3), with plasma exposure and then covered by an occlusive dressing on 0, 1, 2 dw (denoted as P3+D3), continuous exposure until 4 dw (denoted as P5), with plasma exposure and then covered by an occlusive dressing on 0, 1, 2, 3, and 4 dw (denoted as P5+D5). Dressing (denoted as D3 or D5) and gas flow exposure (denoted GF3 or GF5) were also conducted as well for the references. The burn wounds were assessed every day to examine the wound size.

Until 14 dw, the mice were sacrificed for H&E staining. The wound area reduction rate was higher for the cases of N₂/Ar micro-plasma exposed wounds than those of gas flow exposed and dressing ones, while the control group exhibited the lowest wound area reduction rate. From this study, non-thermal N₂/Ar micro-plasma is presumably effective for the stimulation of newly-born cells growth and proliferation [1] and burn wound healing in mice.