Anti-inflammatory effects of cold atmospheric plasma irradiation on the THP-1 human acute monocytic leukemia cell line.

Cold atmospheric plasma (CAP) has been studied and clinically applied to treat chronic wounds, cancer, periodontitis, and other diseases. CAP exerts cytotoxic, bactericidal, cell-proliferative, and anti-inflammatory effects on living tissues by generating reactive species. Therefore, CAP holds promise as a treatment for diseases involving chronic inflammation and bacterial infections. However, the cellular mechanisms underlying these anti-inflammatory effects of CAP are still unclear. Thus, this study aimed to elucidate the anti-inflammatory mechanisms of CAP in vitro. The human acute monocytic leukemia cell line, THP-1, was stimulated with lipopolysaccharide and irradiated with CAP, and the cytotoxic effects of CAP were evaluated. Time-course differentiation of gene expression was analyzed, and key transcription factors were identified via transcriptome analysis. Additionally, the nuclear localization of the CAP-induced transcription factor was examined using western blotting. The results indicated that CAP showed no cytotoxic effects after less than 70 s of irradiation and significantly inhibited interleukin 6 (IL6) expression after more than 40 s of irradiation. Transcriptome analysis revealed many differentially expressed genes (DEGs) following CAP irradiation at all time points. Cluster analysis classified the DEGs into four distinct groups, each with time-dependent characteristics. Gene ontology and gene set enrichment analyses revealed CAP-induced suppression of IL6 production, other inflammatory responses, and the expression of genes related to major histocompatibility complex (MHC) class II. Transcription factor analysis suggested that nuclear factor erythroid 2-related factor 2 (NRF2), which suppresses intracellular oxidative stress, is the most activated transcription factor. Contrarily, regulatory factor X5, which regulates MHC class II expression, is the most suppressed transcription factor. Western blotting revealed the nuclear localization of NRF2 following CAP irradiation. These data suggest that CAP suppresses the inflammatory response, possibly by promoting NRF2 nuclear translocation

Surface Modification of Fluoropolymer Using Open-Air Plasma Treatment at Atmospheric Pressure with Ar, Ar＋O2, and Ar＋H2 for Application in HighAdhesion Metal Wiring Patterns

We performed open-air plasma treatment of polytetrafluoroethylene (PTFE) at atmospheric pressure to increase the adhesion strength between PTFE and an Ag metal film formed from Ag ink. Coloration of the PTFE surface occurred during 600 s treatment with Ar plasma. The Ag/PTFE adhesion strength was 0.06 N/mm. To resolve the problem of coloration and to improve the adhesion strength, O2 or H2 gas was added. During treatment with Ar+O2 plasma with O2 content of 0.33% for 600 s, no coloration occurred but the adhesion strength decreased to zero. During treatment with Ar+H2 plasma for 600 s, coloration did not occur. Moreover, the adhesion strength increased to 0.25-0.55 N/mm. These results showed that H2 addition was effective for preventing coloration and improving adhesion strength during long-period plasma treatment. Furthermore, the uniformity of surface treatment with Ar+H2 plasma was higher than that for Ar plasma

Effect of Plasma Gas Species and Plasma Gas Temperature on Copper Oxide Removal

identifier:oai:t2r2.star.titech.ac.jp:5024559

A Basic Study on Application of Atmospheric-pressure Low-temperature Plasma to Dental Whitening: Bleaching Effect of Multi-gas Plasma Jet with Various Gas Species

identifier:oai:t2r2.star.titech.ac.jp:5038498

ダメージフリーマルチガスプラズマジェットによるポリイミドフィルムの親水化処理

identifier:oai:t2r2.star.titech.ac.jp:5021227