Margolis L B, Victorov A V, Bergelson L D
Biochim Biophys Acta. 1982 Jun 8;720(3):259-65. doi: 10.1016/0167-4889(82)90049-0.
A new approach has been developed for studying the transfer of liposome-entrapped substances into cells. The cells are incubated with liposomes containing two markers that in the free (non-entrapped) state enter the cells at different rates. Comparison of the ratio of cell-associated markers applied either in free or in liposome-entrapped form permits the evaluation of different pathways of cellular uptake of the intraliposomal substances. When epithelial cell sheets were incubated with egg phosphatidylcholine liposomes containing two different sugars they became cell-associated at a ratio different from their initial ratio inside the liposomes. Since the cell-associated ratio was shifted towards the value observed when the cells were incubated with a mixture of the two sugars in the free state, it is suggested that the liposomes become permeable during incubation and that the liberated substances enter the cells in the free form. On the other hand, cell-liposome interaction was demonstrated by NMR measurement and gel-filtration experiments to result in transformation of small unilamellar liposomes into larger multilayered aggregates. This transformation depends on the contact of the liposomes with the cell sheet. It is supposed that interliposomal aggregation is the underlying mechanism of cell-induced leakage of liposomes.
已开发出一种新方法用于研究脂质体包裹物质向细胞内的转运。将细胞与含有两种标记物的脂质体一起孵育，这两种标记物在游离（未包裹）状态下以不同速率进入细胞。比较以游离形式或脂质体包裹形式应用的与细胞相关的标记物的比例，可以评估脂质体内物质进入细胞的不同途径。当上皮细胞片与含有两种不同糖类的卵磷脂脂质体一起孵育时，它们与细胞结合的比例与其在脂质体内的初始比例不同。由于与细胞结合的比例向细胞与游离状态下的两种糖类混合物一起孵育时观察到的值偏移，表明脂质体在孵育过程中变得可渗透，释放出的物质以游离形式进入细胞。另一方面，通过核磁共振测量和凝胶过滤实验证明细胞 - 脂质体相互作用导致小单层脂质体转变为更大的多层聚集体。这种转变取决于脂质体与细胞片的接触。据推测，脂质体间的聚集是细胞诱导脂质体渗漏的潜在机制。
