Département de Médecine Nucléaire et de Radiobiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12ème Avenue Nord, Sherbrooke, QC J1H 5N4, Canada.
Molecules. 2023 Dec 18;28(24):8144. doi: 10.3390/molecules28248144.
(1) Background: Radioprotective agents have garnered considerable interest due to their prospective applications in radiotherapy, public health medicine, and situations of large-scale accidental radiation exposure or impending radiological emergencies. Cystamine, an organic diamino-disulfide compound, is recognized for its radiation-protective and antioxidant properties. This study aims to utilize the aqueous ferrous sulfate (Fricke) dosimeter to measure the free-radical scavenging capabilities of cystamine during irradiation by fast carbon ions. This analysis spans an energy range from 6 to 500 MeV per nucleon, which correlates with "linear energy transfer" (LET) values ranging from approximately 248 keV/μm down to 9.3 keV/μm. (2) Methods: Monte Carlo track chemistry calculations were used to simulate the radiation-induced chemistry of aerated Fricke-cystamine solutions across a broad spectrum of cystamine concentrations, ranging from 10 to 1 M. (3) Results: In irradiated Fricke solutions containing cystamine, cystamine is observed to hinder the oxidation of Fe ions, an effect triggered by oxidizing agents from the radiolysis of acidic water, resulting in reduced Fe ion production. Our simulations, conducted both with and without accounting for the multiple ionization of water, confirm cystamine's ability to capture free radicals, highlighting its strong antioxidant properties. Aligning with prior research, our simulations also indicate that the protective and antioxidant efficiency of cystamine diminishes with increasing LET of the radiation. This result can be attributed to the changes in the geometry of the track structures when transitioning from lower to higher LETs. (4) Conclusions: If we can apply these fundamental research findings to biological systems at a physiological pH, the use of cystamine alongside carbon-ion hadrontherapy could present a promising approach to further improve the therapeutic ratio in cancer treatments.
(1) 背景：由于在放射治疗、公共卫生医学以及大规模意外辐射暴露或即将发生的放射性紧急情况等情况下的潜在应用，辐射防护剂引起了相当大的关注。胱胺是一种有机二氨基二硫化合物，因其具有辐射防护和抗氧化特性而受到认可。本研究旨在利用水性硫酸亚铁（Fricke）剂量计测量快碳离子辐照下胱胺的自由基清除能力。该分析涵盖了 6 至 500 MeV/核子的能量范围，与“线性能量转移”（LET）值相关，范围从大约 248 keV/μm 到 9.3 keV/μm。(2) 方法：使用蒙特卡罗轨道化学计算模拟了充气 Fricke-胱胺溶液在广泛的胱胺浓度范围内的辐射诱导化学，浓度范围从 10 到 1 M。(3) 结果：在含有胱胺的辐照 Fricke 溶液中，观察到胱胺阻碍了 Fe 离子的氧化，这是由酸性水中辐射分解产生的氧化剂引起的，导致 Fe 离子生成减少。我们的模拟既考虑了水的多次电离，也没有考虑水的多次电离，证实了胱胺捕获自由基的能力，突出了其强大的抗氧化特性。与先前的研究一致，我们的模拟还表明，胱胺的保护和抗氧化效率随着辐射的 LET 增加而降低。这一结果可以归因于从较低 LET 过渡到较高 LET 时轨道结构几何形状的变化。(4) 结论：如果我们能够将这些基础研究结果应用于生理 pH 值下的生物系统，那么在碳离子强子治疗中联合使用胱胺可能是进一步提高癌症治疗治疗比的有前途的方法。
