文献：

Optimisation of glutathione conjugation to liposomes quantified with a validated HPLC assay

文献链接：

https://www.sciencedirect.com/science/article/abs/pii/S0378517319304855

作者：

Joy N Reginald-Opara, Darren Svirskis, Simon J O'Carroll, Sreevalsan Sreebhavan, Justin M Dean, Zimei Wu

相关产品：

磷脂-聚乙二醇-马来酰亚胺 DSPE-PEG-Mal

磷脂-聚乙二醇2000-马来酰亚胺 DSPE-PEG2000-Mal

磷脂-聚乙二醇3400-马来酰亚胺 DSPE-PEG3400-Mal

磷脂-聚乙二醇5000-马来酰亚胺 DSPE-PEG5000-Mal

原文摘要：

Glutathione (GSH) grafted onto nanoliposomes (GSH-liposomes) have the potential to enhance drug delivery into the brain. GSH is known to be an unstable tripeptide, however, despite widespread use to promote active transport its stability has been largely ignored to date. Therefore this study focuses on the optimisation of GSH conjugation with liposomes, supported with a validated HPLC assay for GSH. An isocratic stability-indicating HPLC assay of GSH was developed after derivatisation of GSH with 5,5'-dithio-bis-2-nitrobenzoic acid and applied for efficient conjugation of GSH to DSPE-PEG2000-maleimide lipid, either in solution or in preformed liposomes (4% molar ratio) at pH 7.4. The conjugation rate was monitored by the HPLC assay to optimise the conjugation conditions, including GSH concentration, GSH:lipid ratio, reaction time, temperature and medium.

图为：磷脂-聚乙二醇-马来酰亚胺 DSPE-PEG-Mal结构式

谷胱甘肽（GSH）接枝到纳米脂质体（GSH脂质体）上具有增强药物向大脑递送的潜力。GSH是一种不稳定的三肽，用于促进活性转运，但其稳定性不好。因此，所以优化GSH与脂质体的结合，并辅以经验证的GSH HPLC测定。在GSH与5，5’-二硫代-双-2-硝基苯甲酸衍生后，用于在pH 7.4下将GSH在溶液或预成型脂质体（4%摩尔比）中结合到DSPE-PEG2000-马来酰亚胺脂质上。通过HPLC测定监测结合速率以优化结合条件，包括GSH浓度、GSH:脂质比、反应时间、温度和培养基。对所得GSH脂质体的理化性质及其GSH密度进行了表征。

在0.05-50µg/ml范围内呈线性，高度灵敏（定量限50 ng/ml），准确（回收率98-102%），日内和日间变异性小于4%。在较高的GSH浓度≥2 mg/ml时，观察到GSH稳定性增强，质谱证实GSH降解主要通过氧化发生。质子核磁共振（1H NMR）光谱和GSH浓度的HPLC分析都证实了GSH-PEG-DSPE缀合物的形成。在*佳条件下，通过插入后或直接缀合方法获得完全缀合，所得GSH脂质体获得4%的GSH密度，具有相似的尺寸（120nm）和ζ电位（-26.7±0.9mV或-29.8±1.5mV）。该研究为优化GSH在脂质体制剂中的结合提供了有关GSH稳定性的有用信息。