Sterilization Mechanism by Functional Radical Transportation of BiocompatiblePlasma Flow

本研究旨在研究非平衡等离子体流中自由基的传输及其杀菌机理，以开发新型的等离子体杀菌系统，以保护人体环境免受病原微生物的感染。本课题的研究结果总结如下：低温大气压下的Ar等离子体可以杀灭大肠杆菌，其灭活原因是等离子体作用下细胞质膜和外膜的破坏，以及等离子体源紫外线照射对核酸的破坏。用电感耦合等离子体质谱(ICPMS)分析存活细胞和细胞质的渗钾情况，并用扫描电子显微镜观察形态。这一成果发表在《应用物理快报》上，并入选《生物物理研究虚拟期刊》。成功地研制了一套能测量放电区强度为10^~(-8)~(-8)的极弱辐射光学分析系统。利用该系统对放电区下游的径向流场进行了光学研究，开发了一种新型的非平衡等离子体流导管灭菌系统。该系统能够在低温低于70摄氏度的条件下，在5分钟内杀灭抗紫外线和耐热细菌。该灭菌是由管内等离子体引起的自由基流引起的，并通过流场分析系统和自由基排放物分析系统进行了阐明，这些结果在5篇学术论文和7项专利中进行了总结，其中包括1项国际专利。

The radical transportation and its sterilization mechanisms in the nonequilibrium plasma flow were studied in this research project for development of innovative plasma sterilization system to protect human environment from infection by pathogenic microorganism. The results of this research project are summarized as follows.Escherichia coli can be sterilized by a low-temperature argon plasma flow at atmospheric pressure and the inactivation of E. coli results from the destructions of the cytoplasmic membrane and the outer membrane under plasma exposure and the destruction of nucleic acids by exposure to ultraviolet radiation from the plasma source. These were clarified by analyzing the surviving cells and the potassium leakage of cytoplasmic material using ICP-MS, and by observing the morphological aspect by SEM. This result was published in the "Applied Physics Letters" and it was selected for the "Virtual Journal of Biological Physics Research". Optical analysis system for very weak emission was successfully developed, which is capable of measuring intensity of 10^<-8> of that in the discharge region. Using this system, the radical flow fields downstream the discharge region was optically investigated.An innovative catheter sterilization system using a nonequilibrium plasma flow was developed. This system is capable of sterilizing anti-UV and anti-heat bacteria within 5 minutes under the condition of low temperature less than 70 degrees Celsius. The sterilization was caused by a radical flow induced by plasma in the tube, which were clarified by analysis systems for the flow fields and radical emissions.Those results were summarized in the 5 academic papers and 7 patents which includes 1 international patent.