Department of Applied Science & Technology, Politecnico di Torino, Corso Duca Degli Abruzzi 24, 10129, Turin, Italy.
Cryobiology. 2021 Feb;98:46-56. doi: 10.1016/j.cryobiol.2020.12.009. Epub 2021 Jan 2.
In the last decades, liposomes acquired a striking success in the biomedical field thanks to their biocompatibility and drug delivery ability. Many liposomal drug formulations have been already approved by the Food and Drug Administration (FDA) and used for the treatment of a wide range of pathologies with or without further engineering. Their clinical application requires strict compliance with high standard quality rules, and it is crucial to employ storage methods that do not affect the integrity of the vesicles and preventing the leakage of their cargo. In this work, the design of a suitable formulation for freeze-drying had been investigated for two different liposomes, DOPC-DOTAP and the PEGylated counterpart, DOPC-DOTAP-DSPE-PEG. The role of various cryoprotectants was evaluated paying attention to their ability to preserve the structural integrity of liposomes. At first, the study was focused on freezing and two methodologies were investigated, quenching in liquid nitrogen and shelf-ramped freezing. This analysis showed that the disaccharides (cellobiose, glucose, lactose, sucrose, and trehalose) and the polyol (mannitol) protected successfully the integrity of liposomes, while during the process, in the presence of a surfactant, liposomes were strongly damaged and fragmented by the ice crystals. Furthermore, the choice of the rate of freezing depended on the different compositions of the lipid bilayer. Finally, the effects of lyophilization on liposomes with and without additives were studied; cellobiose, lactose and trehalose showed encouraging results for the maintenance of the morpho-functional parameters of liposomes during the entire freeze-drying process.
在过去的几十年中，由于脂质体的生物相容性和药物传递能力，它们在生物医学领域取得了显著的成功。许多脂质体药物制剂已经获得了美国食品和药物管理局（FDA）的批准，并用于治疗广泛的病理疾病，无论是否进行进一步的工程设计。它们的临床应用需要严格遵守高标准的质量规则，并且使用不会影响囊泡完整性并防止其货物泄漏的储存方法至关重要。在这项工作中，已经研究了两种不同的脂质体，DOPC-DOTAP 和聚乙二醇化的对应物 DOPC-DOTAP-DSPE-PEG 的冻干合适配方的设计。评估了各种冷冻保护剂的作用，注意它们保持脂质体结构完整性的能力。首先，研究集中在冷冻上，并研究了两种方法，即液氮淬火和货架斜坡冷冻。该分析表明，二糖（纤维二糖、葡萄糖、乳糖、蔗糖和海藻糖）和多元醇（甘露醇）成功地保护了脂质体的完整性，而在存在表面活性剂的情况下，脂质体被冰晶强烈破坏和碎片化。此外，冷冻速率的选择取决于脂质双层的不同组成。最后，研究了添加剂存在和不存在时对脂质体的冷冻干燥的影响；纤维二糖、乳糖和海藻糖在整个冷冻干燥过程中对维持脂质体的形态功能参数表现出令人鼓舞的结果。
