Université Paris-Sud XI, Faculté de Pharmacie, UMR CNRS 8612, IFR 141, 92296 Châtenay-Malabry Cedex, France.
Int J Pharm. 2009 Nov 3;381(2):140-5. doi: 10.1016/j.ijpharm.2009.04.002. Epub 2009 Apr 11.
Nucleoside analogues are potent anticancer or antiviral agents that however display some limitations (rapid metabolism, induction of resistance). In order to overcome these drawbacks, we recently proposed new prodrugs, in which nucleoside analogues were covalently coupled to squalene (SQ). The resulting amphiphilic compounds spontaneously formed nanoparticles (NPs) and displayed a promising efficacy both in vitro and in vivo. Since long-term stability is essential for further clinical development we needed to develop a laboratory-scale freeze-drying protocol in order to improve the colloidal stability of those NPs. Squalenoylated gemcitabine (SQdFdC) has been successfully freeze-dried with trehalose (10%, w/w) as a cryoprotectant. Concentrations of SQdFdC up to 4mg/mL after freeze-drying and rehydration have been obtained, which is necessary for in vivo studies. Stability measurements by dynamic light scattering showed that trehalose had a stabilizing effect on SQdFdC NPs, and that freeze-dried SQdFdC NPs could be stored up to four months at room temperature before rehydration, without loss of stability. In vitro cytotoxicity studies on three murine cell lines showed that SQdFdC NPs retained their cytotoxic activity after freeze-drying. We showed that this freeze-drying protocol could also be applied to squalenoylated didanosine (SQddI) and zalcitabine (SQddC). Overall, these results allow for the use of freeze-dried NPs in upcoming preclinical trials of the different squalenoylated compounds developed in our laboratory.
核苷类似物是有效的抗癌或抗病毒药物，但它们存在一些局限性（快速代谢、诱导耐药性）。为了克服这些缺点，我们最近提出了新的前药，即将核苷类似物与角鲨烯（SQ）共价连接。得到的两亲化合物会自发形成纳米颗粒（NPs），在体外和体内都显示出有希望的疗效。由于长期稳定性对于进一步的临床发展至关重要，我们需要开发实验室规模的冷冻干燥方案，以提高这些 NPs 的胶体稳定性。已经成功地用海藻糖（10%，w/w）作为冷冻保护剂冷冻干燥了角鲨烯化吉西他滨（SQdFdC）。在冷冻干燥和复水后可以获得高达 4mg/mL 的 SQdFdC 浓度，这对于体内研究是必要的。动态光散射的稳定性测量表明，海藻糖对角鲨烯化吉西他滨 NPs 具有稳定作用，并且冷冻干燥的 SQdFdC NPs 在复水前可以在室温下储存长达四个月而不会失去稳定性。对三种鼠细胞系的体外细胞毒性研究表明，冷冻干燥后 SQdFdC NPs 保留了其细胞毒性活性。我们表明，该冷冻干燥方案也可应用于角鲨烯化双脱氧肌苷（SQddI）和扎西他滨（SQddC）。总的来说，这些结果允许在我们实验室开发的不同角鲨烯化化合物的即将进行的临床前试验中使用冷冻干燥的 NPs。
