Year: 2026
Type: dissertation
Abstract: Based on previous research, this study tries to promote the introduction efficiency of reactive nitrogen species (RNS) in plasma-activated solutions.L-arginine solution was selected, and by exposing L-arginine solution to cold atmospheric plasma, plasmatreated L-arginine (PTA) was generated.Its antitumor effect and working mechanism were researched.In vitro cytotoxicity evaluation was performed on MCF-7 breast cancer cells and MCF-10A breast epithelial cells using PTA solutions.The results demonstrated that PTA prepared from a series of initial L-arginine concentrations ranging from 10 mM to 474.7 mM exerted pronounced cytotoxic effects on MCF-7 cells under certain dilution conditions, while causing minimal damage to MCF-10A cells.Notably, PTA10 exhibited clear selectivity at a 100-fold dilution, whereas PTA118, PTA237, and PTA474 exhibited the most efficient selectivity at a 64-fold dilution.Fluorescence imaging using Caspase-3/7 staining revealed that MCF-7 cells underwent apoptosis within 2 hours after exposure to the PTA10 and PTA474 solutions, and the number of apoptotic cells was positively correlated with the concentration of PTA.However, apoptosis was no longer observed in MCF-7 cells at 24 hours after PTA treatment.Despite this, a significant and selective suppression of MCF-7 cell viability was still evident at 72 hours following PTA treatment.These findings indicate that PTA induces apoptosis in cancer cells within the first few hours of exposure, whereas the sustained inhibition of cell viability beyond 24 hours is likely attributable to mechanisms other than apoptosis.vi that promotes proliferation, survival, and therapeutic resistance in breast cancer cells, its downregulation provides molecular evidence for the sustained suppression of MCF-7 cell viability induced by PTA-Exos.These results demonstrate that PTA induces an exosomal cargo alternation that contributes to the sustained inhibition after 24 hours.This study demonstrates a two-stage antitumor mechanism of PTA.In the early stage (within 24 hours), RONS and newly formed organics induce rapid apoptosis.In the later stage (beyond 24 hours), the sustained inhibitory effects on cancer cells are mediated by exosomal cargo, particularly through the downregulation of miR-21.PTA represents a low-cost and readily accessible therapeutic candidate.These findings provide an important mechanistic basis for the safety evaluation of PTA-based therapies.
Institution: Nagoya University
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7163848435