Healing Effect Study Of Image-Guided Cold Atmosphere Plasma Therapy On Infected Wound Of Mice

Cutaneous wounds, especially chronic wounds, represents major tissue anomalies. High incidence, high prevalence and high costs of chronic wound have become a major problem of health care worldwide. Nearly 1%-2% of chronic wounds will develop into leg and foot ulcers. The annual cost for wound management is more than S13 billion. Despite many technical and clinical advances in wound management, the current clinical practice is challenged by the lack of quantitative tools for non-invasive wound assessment and the lack of convenient methods for accelerating wound healing process.As a result of both the better understanding of complex plasma phenomena and the development of new plasma sources in the past few years, plasma medicine has developed into an innovative field. Cold atmosphere plasma (CAP) has shown potential therapeutic benefit in contact-free disinfection, blood coagulation, and accelerated wound healing. The CAP has a complex composition:a mixture of charged particles, reactive species (mainly reactive oxygen species [ROS] and reac-tive nitrogen species [RNS]) and, in part, UV radiation. There are many species of plasma, CAP is usually produced in the ambient air, rare gases or a mixture of them. Because of the general generation enviroment, the CAP device can be designed to generate cold plasma in the ambient air. Experiments show that cold atmosphere plasma (CAP) allow painless and contact-free use in clinic, even in microscopic openings, without damaging healthy tissue. In dermatology, new horizons are being opened for wound healing, tissue regeneration, therapy of skin infections, and probably many more diseases.To validate the healing effect of CAP on infected wound, we devepoded an image-guided plasma therapy for wound treatment and non-invasive assessment. The plasma was generated by a portable CAP device. A multimodal imaging system that combined multi spectral imaging system and laser speckle imaging system was also developed for quantitative assessment of wound tissue oxygenation and blood perfusion during treatment process. The proposed wound imaging and treatment systems were validated on a wounded mouse model with dorsal skinfold chamber and staphylococcus aureus infection. All the mice used in the experiment was devided into three subgroups:(1) with no infection nor treatment (2) infection without treatment (3) infection with treatment. The treatment dosage was 2 mins per day. In order to evaluate the anti-bacteria effect, we quantified the bacterial load before and after the treatment by a standard colony couting method. Histological and immunohistochemical analysis was carried out to analyze the change of interior cells in wounds. Further more, in the research of relationship between therapeutic depth and sterilization effect, we treated the sample and a spinning-disk confocal microscope was used to monitor the live/dead situation.In summary, our imaging and therapeutic experiments have implied that plasma treatment may potentially improve the wound healing process by increasing wound tissue oxygenation and blood perfusion at a certain phase of healing process, inducing the positive therapeutic effects in terms of the microvessel density, the immune response, and the proliferative activity of basal layer cells and killing bacteria in the wound. Our research work provides a technique support for control infection and improving the wound healing.