Liposomes are promising vectors for pulmonary drug delivery, and have been used in marketed inhalation products. Membrane fluidity is an important property of liposomes. However, the influence of liposome membrane fluidity on its interaction with pulmonary physiological barriers is still unclear and needs elucidation. Here, a series of PEGylated DPPC (1,2-dihexadecanoyl-rac-glycero-3-phosphocholine) liposomes with different membrane fluidity were prepared, and their interaction with different pulmonary physiological barriers, including the mucus permeation capacity, macrophage uptake, trachea distribution and retention behavior, was investigated. The liposomes exhibited sizes of around 100 nm, near-neutral surface charge, and the membrane fluidity increased with increasing cholesterol ratio. In vitro studies showed that the liposomes with lower membrane fluidity presented optimal mucus permeation efficiency, while those with higher membrane fluidity displayed lower macrophage uptake. An in vivo trachea distribution study revealed that liposomes with low or medium membrane fluidity exhibited enhanced trachea permeation. No significant difference in lung retention was found among these liposomes. In conclusion, the mucus permeation and macrophage phagocytosis behavior of liposomes could be well tuned by changing their membrane fluidity.

中文翻译：

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探索吸入脂质体膜流动性对其与肺部生理屏障相互作用的影响

脂质体是用于肺部药物递送的有前途的载体，并且已经用于市售的吸入产品中。膜的流动性是脂质体的重要特性。然而，脂质体膜流动性对其与肺部生理屏障相互作用的影响尚不清楚，需要阐明。在这里，制备了一系列具有不同膜流动性的聚乙二醇化DPPC（1,2-二十六烷酰基-rac-甘油-3-磷酸胆碱）脂质体，它们与不同的肺生理屏障相互作用，包括黏液渗透能力，巨噬细胞摄取，气管分布。和保留行为，进行了调查。脂质体的大小约为100 nm，表面电荷接近中性，并且膜的流动性随胆固醇比率的增加而增加。体外研究表明，膜流动性较低的脂质体表现出最佳的粘液渗透效率，而膜流动性较高的脂质体显示出较低的巨噬细胞摄取。的体内气管分布研究显示具有低或中等的膜流动性脂质体表现出增强的渗透气管。在这些脂质体之间未发现肺滞留的显着差异。总之，通过改变脂质体的膜流动性，可以很好地调节脂质体的粘液渗透和巨噬细胞吞噬行为。