Hexyl aminolevulinate (HAL) is a lipophilic derivative of 5‐aminolevulinic acid (5‐ALA) and can induce more protoporphyrin IX (PpIX) formation and stronger fluorescence intensity (FI) than 5‐ALA, which will greatly facilitate photodynamic diagnosis and therapy. The main drawback of HAL is its low solubility in neutral aqueous media. In this study, surfactants were used to increase HAL solubility in the cell culture medium and serum, followed by in vitro fluorescence formation measurement in human pancreatic cancer cells (SW1990) and in vivo fluorescence detection in tumor‐bearing mice. The results showed that Tween 80 (TW80) and Kolliphor® HS 15 (HS15) increased the solubility of HAL in the selected media. Although TW80 and HS15 exhibited in vitro cytotoxicity at high concentrations (5 mg mL−1), they facilitated fluorescent signal formation at the early stage of cell incubation. When surfactants were used, the FI should be determined without the routine washing process because surfactant‐containing culture medium caused the loss of synthesized PpIX during the washing process. When HAL dissolved in TW80 solution was injected intraperitoneally into pancreatic cancer‐bearing mice at a dose of 50 mg kg−1, the tumors exhibited red fluorescence, which indicated that systemic administration of surfactant‐solubilized HAL might be applicable for tumor fluorescence detection in vivo.

中文翻译：

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表面活性剂溶解氨基乙酰丙酸己酯用于肿瘤荧光检测

氨基乙酰丙酸己酯 (HAL) 是 5-氨基乙酰丙酸 (5-ALA) 的亲脂性衍生物，与 5-ALA 相比，可以诱导更多的原卟啉 IX (PpIX) 形成和更强的荧光强度 (FI)，这将极大地促进光动力诊断和治疗。HAL 的主要缺点是其在中性水性介质中的溶解度低。在这项研究中，表面活性剂被用来增加 HAL 在细胞培养基和血清中的溶解度，然后在人胰腺癌细胞 (SW1990) 中进行体外荧光形成测量和荷瘤小鼠体内荧光检测。结果表明，吐温 80 (TW80) 和 Kolliphor® HS 15 (HS15) 增加了 HAL 在所选介质中的溶解度。尽管 TW80 和 HS15 在高浓度（5 mg mL-1）下表现出体外细胞毒性，它们促进了细胞孵化早期荧光信号的形成。当使用表面活性剂时，应在没有常规洗涤过程的情况下确定 FI，因为含有表面活性剂的培养基会导致洗涤过程中合成 PpIX 的损失。将溶解在 TW80 溶液中的 HAL 以 50 mg kg-1 的剂量腹腔注射到荷胰腺癌小鼠体内时，肿瘤显示红色荧光，表明全身给药表面活性剂溶解的 HAL 可能适用于体内肿瘤荧光检测.