| Summary: | 碩士 === 國立成功大學 === 材料科學及工程學系 === 102 === “Plasma medicine” has been growingly developed in recent years. For medical applications, a plasma device is usually atmospheric, non-thermal, and miniature as a type of micro-plasmas. Thus, the effect of micro-plasma with a target substance is mostly correlated with relatively long-lived species that may induce an interaction within a tissue-tolerable duration. As the result, the diagnoses of plasma composition, exposed environment, and possibly induced tissue-response are important to clarify the bio-safety issue, though micro-plasmas are known to be weakly loaded to its surrounding and a treated substance. In this study, a jet-type Ar and Ar/N2 micro-plasmas with suggested parameters (with a controlled plasma composition) were utilized, followed by examining the exposed environment, based on general regulations. The induced tissue-response was simulated by loading on a buffer solution and medium, followed by verifying nitrite and reactive oxygen species in liquid. In summary, plasma composition from the suggested device contains (1) UVA, B, and C: the intensities are decreased with the working distance between plasma nozzle and a target substance (e.g., at the working distance of 6 mm, the intensities are close to their background values), (2) the generated nitric oxide, and ozone species: the former ones are not measurable, however, the latter can be accumulated as the exposure time is extended (but still far below the safety range), and (3) the generated species in liquid: nitrite and reactive oxygen species are increased with plasma exposure time, however, it is quite out of the usual plasma exposure time range. Consequently, by adjusting plasma composition and controlling the required exposure time, the currently applied micro-plasma treatment is presumably tissue-tolerable.
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