Suchyta Dakota J, Schoenfisch Mark H
Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599.
RSC Adv. 2017;7(84):53236-53246. doi: 10.1039/C7RA09899E. Epub 2017 Nov 20.
In this study, fast and slow nitric oxide (NO)-releasing liposomes (half-lives of 2.5 and >72 h, respectively) were prepared by encapsulation of N-propyl-1,3-propanediamine/NO (PAPA/NO) and diethylenetriamine/NO (DETA/NO), respectively, via reverse phase evaporation. The anticancer activity of the otherwise equivalent fast and slow NO-releasing systems was evaluated against several distinct pancreatic, colorectal, and breast cancer cell lines. The anticancer assays (via cytotoxicity) over 72 h revealed that the slower NO-releasing liposomes consistently required lower NO payloads (LD50 <3 μg/mL) relative to the fast NO-release system (LD50 >6 μg/mL) to elicit cytotoxicity. The mechanism of intracellular NO build-up in cancer cells was studied using confocal fluorescence microscopy and flow cytometry, the results of which indicated that a more gradual NO accumulation was characteristic of the slow NO-release system. Protein expression via Western blot analysis revealed that slower NO release resulted in more necrotic/apoptotic cells, while faster release reduced the number of mitotic cells to a greater extent. Overall, these studies demonstrate the potential of NO-releasing liposomes for anticancer therapy and highlight the significance of release kinetics (and NO payloads) required to induce cell death.
在本研究中，通过反相蒸发分别将N-丙基-1,3-丙二胺/一氧化氮（PAPA/NO）和二亚乙基三胺/一氧化氮（DETA/NO）包封，制备了快速和慢速释放一氧化氮（NO）的脂质体（半衰期分别为2.5小时和>72小时）。针对几种不同的胰腺、结肠和乳腺癌细胞系，评估了在其他方面等效的快速和慢速释放NO系统的抗癌活性。超过72小时的抗癌试验（通过细胞毒性）表明，相对于快速释放NO的系统（半数致死剂量>6μg/mL），慢速释放NO的脂质体始终需要较低的NO载量（半数致死剂量<3μg/mL）来引发细胞毒性。使用共聚焦荧光显微镜和流式细胞术研究了癌细胞内NO积累的机制，结果表明，缓慢的NO积累是慢速释放NO系统的特征。通过蛋白质印迹分析的蛋白质表达显示，较慢的NO释放导致更多坏死/凋亡细胞，而较快的释放则在更大程度上减少有丝分裂细胞的数量。总体而言，这些研究证明了释放NO的脂质体在抗癌治疗中的潜力，并突出了诱导细胞死亡所需的释放动力学（和NO载量）的重要性。
