Villavicencio Cecilia Julieta Garcia, Silva Beatriz de Campos, Matara Anesu, Ptasinska Sylwia
Radiation Laboratory, University of Notre Dame, Notre Dame, IN 46556, USA.
Department of Physics and Astronomy, University of Notre Dame, Notre Dame, IN 46556, USA.
Molecules. 2024 Dec 13;29(24):5889. doi: 10.3390/molecules29245889.
Low-temperature plasma (LTP) offers a promising alternative for cancer therapy, as it targets malignant cells selectively while minimizing damage to healthy tissues. Upon interaction with an aqueous solution, LTP generates reactive oxygen and nitrogen species and thereby influences the solution's pH, which is a crucial factor in cancer proliferation and response to treatment. This study investigated the effects of LTP on the pH of aqueous solutions, with a focus on the effect of LTP parameters such as voltage, frequency, and irradiation time. In addition, it explored the influence of solution composition, specifically the presence of the amino acids, glycine and serine, on pH changes; these amino acids are known to play significant roles in cancer proliferation. Our results indicated that LTP induces acidification in deionized water, in which the extent of acidification increased proportionally with plasma parameters. In glycine-containing solutions, pH changes were concentration-dependent, whereas serine-containing solutions maintained a constant pH across all tested concentrations. To investigate potential changes to the structural properties of glycine and serine exposed to LTP that could be responsible for different pH responses, we analyzed the samples using FTIR spectroscopy. A significant decrease in absorbance was observed for solutions with low concentrations of amino acids, suggesting their degradation.
低温等离子体（LTP）为癌症治疗提供了一种有前景的替代方法，因为它能选择性地靶向恶性细胞，同时将对健康组织的损害降至最低。与水溶液相互作用时，LTP会产生活性氧和氮物种，从而影响溶液的pH值，而pH值是癌症增殖和治疗反应的关键因素。本研究调查了LTP对水溶液pH值的影响，重点关注LTP参数（如电压、频率和辐照时间）的作用。此外，还探讨了溶液成分，特别是氨基酸甘氨酸和丝氨酸的存在对pH值变化的影响；已知这些氨基酸在癌症增殖中起重要作用。我们的结果表明，LTP会使去离子水酸化，酸化程度与等离子体参数成比例增加。在含甘氨酸的溶液中，pH值变化取决于浓度，而含丝氨酸的溶液在所有测试浓度下pH值保持恒定。为了研究暴露于LTP的甘氨酸和丝氨酸的结构性质可能发生的潜在变化，而这些变化可能是导致不同pH值反应的原因，我们使用傅里叶变换红外光谱（FTIR）对样品进行了分析。对于低浓度氨基酸的溶液，观察到吸光度显著下降，表明它们发生了降解。
