Effects of Cold Atmospheric Pressure Plasma on Accelerating Acute Wound Healing: A Comparative Study among 4 Different Treatment Groups

Cold atmospheric pressure plasma (CAP) has been expected to be effective for wound healing among plasma medicines and has been attracting attention. The aim of this retrospective clinical study was to evaluate and compare the effects of CAP on acute wounds created by a fractional CO2 (FXCO2) laser on four treatment groups. Methods: This study was conducted between September 2017 and November 2018. Radiated surface wounds were created using a FXCO2 laser on four identically-sized regions on the medial side of the left forearm of 12 healthy volunteer subjects, for a total of 48 treatment regions. Each region was then randomly assigned to one of four groups: 1) no treatment (control group), 2) irradiated CAP for 60 seconds (plasma group), 3) topical application of ointment containing betamethasone valerate (steroid group), or 4) two to three sprays of basic fibroblast growth factor (bFGF group). The primary outcome of the skin was the change in absolute values of lightness index (L*), redness index (a*I) of L*a*b color space, arithmetical mean roughness (Ra), and mean melanin concentration. The secondary outcome was the clinical condition of the wounds, including inflammation, crust formation, and hyper/hypo-pigmentation on the recovering skin surface relative to the surrounding intact skin. Each item was evaluated at post-treatment 0, 1, 3, 7, 14, 28 days and 1 year. Results: Although no significant difference was observed among all groups, the CAP group exhibited more rapid recovery regarding a*I and Ra. No side-effects were observed in the CAP group. Conclusion: CAP is considered to accelerate healing of irradiated wounds via anti-inflammatory activity. Our study confirmed the effectiveness and safety of CAP which is devoid of side-effects of conventional therapies, and may aid in future development of medical plasma therapies.