Development Of Array Plasma Flashlight And Its Application In Wound Healing

In recent years,the research on plasma technology has always been at the forefront of science,and it has been widely used in various fields.With the emergence of Atmospheric Pressure Low Temperature Plasma Jets(APPJs),it has attracted a lot of attention from researchers in the field of biomedicine due to the low environmental requirements,low gas temperature which can be close to room temperature,and high activity.Based on the biomedical application of APPJs,a portable array plasma source has been developed and improved,which is named by array plasma flashlight.And then the analysis of the active substances produced by the flashlight has been finished by optical diagnosis.In addition,in order to study the role of the flashlight in wound healing,in vitro sterilization experiments and animal wound healing experiments were conducted.(1)At first,the design of array plasma flashlight is introduced.It is a plasma jet source driven by a lithium battery,which does not require gas and flow assistance,that makes it convenient to carry.The electrode is arranged in a circular array,and the jet cross section is increased to 700mm² by the arrangement.There are not electric shock or obvious heat while human body contact it directly for several minutes.(2)Secondly,the flashlight was analysised by optical diagnosis.Through emission spectroscopy,it was found that there are a large number of excited state N₂ and N₂⁺molecules in the particles produced by the flashlight.At the same time,the line of singlet O atom is also detected,which is a important active particle in plasma.In addition,ozone was measured by absorption spectroscopy,the results show that its absolute concentration was decreasing with the increase of distance.And it is increasing while the applied voltage increase.The ozone concentration is on the order of 100 ppm in this experiment.(3)And then,in vitro sterilization test of the flashlight is conducted.Strains were selected from the three most common bacteria in wound infections:Staphylococcus aureus,E.coli,and Pseudomonas aeruginosa.The results show that more than 6 orders of magnitude of Staphylococcus aureus and E.coli were inactivated by 5 minutes treatment,while only 3minutes treatment is able to inactivate more than 6 orders of magnitude of Pseudomonas aeruginosa.On this basis,an in vitro Staphylococcus aureus biofilm model was established,and the bacteria in the biofilm were tested.The result shows that the treatment of 5 min will only inactivate almost 4 orders of magnitude bacteria.It is enough to prove that the bacterial biofilm also has a strong obstacle to plasma high-energy particles and active particles.(4)Based on the most representative strain of wound infection:Staphylococcus aureus,the model of bacterial infection of skin wounds on the back of mice was established,and an autologous control was also established.The results show that the array plasma flashlight has the function of promoting wound healing and the effect shows dose dependence.Plasma flashlight treatment for 1min can effectively promote wound healing.With the increase of treatment time,treatment gradually shows a tendency to hinder wound healing.Histological observation and immunohistochemical analysis based on 1min treatment showed that the treatment will reduce inflammation and promote the secretion of cytokine?-SMA,thereby accelerating wound healing.