Bacterial composition and healing tendency with cold atmospheric plasma treatment in diabetic wounds.

Hard-to-heal (chronic) wounds in patients with diabetes represent a considerable, difficult-to-manage burden, and significantly increase the risk of amputations of lower extremities. These lesions are often accompanied by infections. Novel therapeutic approaches are urgently needed in the field of wound management. Cold atmospheric plasma (CAP) is a promising tool in the management of hard-to-heal wounds. Its beneficial use can be attributed to the reduction of bacterial load and direct stimulation of tissue regeneration. The effectiveness of different CAP devices for the treatment of hard-to-heal wounds is well documented by clinical case series and randomised controlled studies. The aim of this prospective, observational study was to investigate the bacterial load and composition in hard-to-heal wounds following CAP treatment, and the impact on long-term wound healing outcome. A total of 22 patients were included in the study. All wounds were exposed to the argon-driven CAP jet kINPen Med (neoplas med GmbH, Germany), in addition to standard phase-adapted wound care. A digital wound camera monitored wound area development over time, while swab tests monitored bacterial colonisation. The results showed that CAP application significantly reduced the bacterial burden almost immediately, although this reduction was not maintained. The analysis revealed a better healing tendency when wounds were colonised by Gram-positive bacteria as opposed to Gram-negative bacteria. Moreover, a higher susceptibility of Gram-negative bacteria to the CAP jet was detected. In conclusion, the bacterial composition of wounds might affect the healing outcome during CAP therapy.