Gas plasma jet technology was recently identified as a potential adjuvant in the palliation of cancer patients. However, a practical point raised is if higher therapeutic efficacy is achieved with the gas plasma applied in direct contact to the tumor tissue (conducting) or during treatment with the remote cloud of reactive oxygen and nitrogen species (ROS/RNS) being expelled. In a bedside-to-bench study, this clinical question was translated into studying these two distinct treatment modalities using a three-dimensional tumor cell-matrix-hydrogel assay with subsequent quantitative confocal imaging. Z-resolved fluorescence analysis of two cancer cell lines revealed greater toxicity of the conducting mode. This result was re-iterated in the growth analysis of vascularized tumor tissue cultured on chicken embryos' CAM using in ovo bioluminescence imaging. Furthermore, for conducting compared to free mode, optical emission spectroscopy revealed stronger RNS signal lines in the gas phase, while both ROS/RNS deposition in the liquid was drastically exacerbated in the conducting mode. Altogether, our results are vital in understanding the importance of standardized treatment distances on the therapeutic efficacy of gas plasma exposure in clinical oncology and will help to give critical implications for clinicians involved in plasma onco-therapy in the future.
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http://dx.doi.org/10.1016/j.freeradbiomed.2022.01.014 | DOI Listing |
J Biophotonics
December 2024
Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic.
We report here on the development of tailored plasmonic AgNPs/C:H:N:O plasma polymer nanocomposites for the detection of the pathogenic bacterium Borrelia afzelii, with high selectivity and sensitivity. Silver (Ag) nanoparticles, generated by a gas aggregation source, are incorporated onto a C:H:N:O plasma polymer matrix, which is deposited by magnetron sputtering of a nylon 6.6.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Laboratory of Plasma Physics (LPP), CNRS, Sorbonne Université, École Polytechnique, Institut Polytechnique de Paris, Palaiseau, France.
Energy conservation dictates that an electron with elementary charge e traversing a vacuum gap formed by electrodes maintained at potential difference U volts acquires maximum energy of eU. In many experiments electrons with energies as high as 3eU have been observed. The experimental discovery of this effect was made over 50 years ago and is still a subject of significant controversy in applications related to x-ray generation from high voltage discharges.
View Article and Find Full Text PDFFree Radic Res
December 2024
Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
Plasma, which was coined by Irving Langmuir in 1928, is the fourth physical state after the solid/liquid/gas phases. Low-temperature plasma (LTP) is a contradictory condition that involves high energy with free radicals at near-body temperatures and was developed through engineering in the 1990's. Research on LTP in engineering and medical fields has rapidly developed since the 2000's.
View Article and Find Full Text PDFDrug Test Anal
December 2024
Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong, China.
Methylsulfonylmethane (MSM), also known as dimethyl sulfone, is a naturally occurring sulphur-containing compound that can be found in plants, animals and humans. MSM can also be a metabolite of dimethyl sulfoxide (DMSO). Due to their anti-inflammatory and analgesic effects, both MSM and DMSO are prohibited substances in horseracing.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Chemical Engineering, University of California, Santa Barbara, California 93106, United States.
AC plasmas directly excited within liquid hydrocarbons were investigated for the production of hydrogen and unsaturated C hydrocarbon in a recirculating liquid "jet" flow configuration. Arc discharges were excited at two different frequencies (60 Hz and 17.3 kHz) in C-C hydrocarbons (hexane, cyclohexane, benzene, toluene, and xylene) to produce H, CH, CH, and CH, along with liquid and solid carbon byproducts.
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