Medical Application Of Cold Atmospheric Plasma

Partâ… Sterilizing effect of cold atmospheric plasma on bacteria Objective To study the sterilizing effect and mechanism of cold atmospheric plasma (CAP) on bacteria preliminarilyMethods Escherichia coli and Staphylococcus aureus were chosed respectively as representative examples of gram-negative bacteria and gram-positive bacteria. Quantitative carrier testmethod was used to carry out laboratory observation on the influencing factors such as different bacterial species, density of bacteria on carrier. Furthermore , the morpho--logical change of bacteria treated by CAP were studied by transmission electron microscope (TEM) .Results These results demonstrated that the sterilizing effect of CAP on Escherichia coli was stronger significantly than on Staphylococcus aureus(P<0.05).The density of bacteria was one of influencing factors. The sterilizing effect of CAP on Staphylococcus aureus was stronger significantly(P<0.05), when The density of bacteria was low than when the density of bacteria was high.The pictures of TEM indicated the surface structure of Staphylococcus aureus treated by CAP could be destroied firstly.Conclusions Our results suggest that CAP can destroy the bacteria very efficiently , and more likely through the damage of cell walls and membranes of microbes treated by CAP. Partâ…¡Effect of cold atmospheric plasma on wounded skin ulcer healingObjective To investigate the effect of cold atmospheric plasma (CAP)on wounded skin ulcer healing in Balb/c mice.Methods Two 6-mm wounds of BalB/c mice were created on the back of each mouse(n = 150) by punch biopsy. The mice were assigned randomly into three groups: control group(the wounds were allowed to heal naturally); He-Ne laser group (the wounds were treated by He-Ne laser ,10 minutes every day);CAP group(the wounds were treated by CAP,10 minutes every day). Wound healing was evaluated on the postoperative days (POD) 4, 7,10and 14 by percent wound closure. Ten mice per group were sacrificed on the POD 4, 7,10, 14. Both wounds were removed and histology was conducted on the wound sites. A scoring system was used to evaluate the wounds. The expression of vascular endothelial growth factors(VEGF)in the wound tissues were detected by using immunohistochemical method on the POD7. The results were quantitated by HPIAS - 1000 system.Results Compared with that of control group ,the average percents wound healing were greater significantly in CAP group on the PODs 7,10(P=0.009,P=0.004); the average scores of histologic examination were highter significantly in CAP group on the PODs 7,10,14(P =0.049,P=0.005 and P=0.010).Compared with that of other two groups, the expression of VEGF was up-regulated significantly in the wound tissues of CAP group(P<0.001 and P=0.037).Conclusion The results show that the CAP positively affect the healing process of wounds, Which may be related to the up-regulation of expression of VEGF in the wound tissues.