Radiotherapy is an important treatment for cancer, but it is associated with major side effects due to the high dose of radiation (generally more than 50 Gy). Because radiation’s low acute and late toxicity, many tumors are treated with fractionated radiation in small doses (< 2 Gy). Scintillator X-ray-induced photodynamic therapy is an efficient methodology for cancer management that employs small doses of X-ray irradiation (< 2 Gy) in a complex process. Here we screened pharmaceutical drug intermediates that are derivatives of thioxanthone (TX) and investigated TX-derived organic pharmaceutical molecules that efficiently undergo X-ray-sensitization to populate triplet excitons (singlet oxygen) for cancer therapy when exposed to low-dose X-ray irradiation. By modifying alkoxy side chain substitutions at the 2-position to tune the molecular packing and intermolecular interactions, the fluorescence and room-temperature phosphorescence of a series of TX derivatives were assessed under X-ray irradiation. The ability of these derivatives to generate singlet oxygen and their potential for treating tumors provide new opportunities for developing organic molecules with simple chemical structures, in which large numbers of triplets can be populated directly under ultralow-dose X-ray irradiation.

中文翻译：

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X 射线敏化剂：由 X 射线直接激活的有机药物中间体，可有效地填充三重态激子，用于癌症治疗


放射治疗是癌症的重要治疗方法，但由于放射剂量较高（通常超过 50 Gy），因此会产生严重的副作用。由于放射的急性和晚期毒性较低，因此许多肿瘤采用小剂量（< 2 Gy）的分段放射治疗。闪烁体 X 射线诱导光动力疗法是一种有效的癌症治疗方法，在复杂的过程中采用小剂量的 X 射线照射（< 2 Gy）。在这里，我们筛选了噻吨酮 (TX) 衍生物的药物中间体，并研究了 TX 衍生的有机药物分子，当暴露于低剂量 X 射线时，这些分子可以有效地进行 X 射线敏化，填充三线态激子（单线态氧），用于癌症治疗辐照。通过修饰2位烷氧基侧链取代来调节分子堆积和分子间相互作用，在X射线照射下评估了一系列TX衍生物的荧光和室温磷光。这些衍生物产生单线态氧的能力及其治疗肿瘤的潜力为开发具有简单化学结构的有机分子提供了新的机会，其中可以在超低剂量X射线照射下直接产生大量三线态。