Liposomes are the predominant drug delivery system widely used in the pharmaceutical industry, but rapid clearance and endosome degradation are the main barriers to improve the delivery efficiency of liposomes, especially for protein or genes. Simulating viral membrane fusion peptides, four asymmetrically dihydrophobic chain polyethylene glycol (PEG) lipids with long circulating and membrane fusion properties have been designed and synthesized with a high yield. The structure of synthetic PEG lipids is characterized by ¹H NMR and mass spectrometry. The critical micelle concentrations of PEG lipids are lower by one or two orders of magnitude compared with traditional surfactants such as SDBS or SDS, which show excellent self-assembly performance of lipids. The size and morphology of liposomes constituted with neutral lipid DOPC and PEG lipid are characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). In the conditions of 50% ethanol and 5–25 mmol L⁻¹ Ca²⁺, the PEG neutral lipid complexes encapsulated pEGFP are almost neutral with a diameter below 300 nm.

中文翻译：

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用于长循环和膜融合的不对称二疏水链聚乙二醇脂质的合成

脂质体是制药行业广泛使用的主要药物递送系统，但快速清除和内体降解是提高脂质体递送效率的主要障碍，尤其是对蛋白质或基因的递送效率。模拟病毒膜融合肽，设计并合成了四种具有长循环和膜融合特性的不对称二疏水链聚乙二醇 (PEG) 脂质。合成 PEG 脂质的结构特点为¹H NMR和质谱。与传统的表面活性剂如SDBS或SDS相比，PEG脂质的临界胶束浓度降低了一个或两个数量级，表现出优异的脂质自组装性能。由中性脂质DOPC和PEG脂质构成的脂质体的大小和形态通过动态光散射（DLS）和透射电子显微镜（TEM）来表征。在 50% 乙醇和 5-25 mmol L ^-1 Ca ²⁺的条件下，包裹 pEGFP 的 PEG 中性脂质复合物几乎是中性的，直径低于 300 nm。