EFFICIENCY OF CYTOPLASMIC DELIVERY BY PH-SENSITIVE LIPOSOMES TO CELLS IN CULTURE
EFFICIENCY OF CYTOPLASMIC DELIVERY BY PH-SENSITIVE LIPOSOMES TO CELLS IN CULTURE
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DOI：
10.1023/a:1015908831507
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发表时间：
1990-08-01
影响因子：
3.7
通讯作者：
SZOKA, FC
中科院分区：
文献类型：
--
作者：
CHU, CJ;DIJKSTRA, J;SZOKA, FC
本文比较了真核细胞系对半琥珀酸胆固醇（CHEMS）和二油基磷脂酰乙醇胺（DOPE）组成的ph敏感脂质体与由CHEMS和二油基磷脂酰胆碱（DOPC）组成的非ph敏感脂质体的细胞内加工过程。ph敏感脂质体可以将包裹的荧光分子[钙黄蛋白、荧光葡聚糖、荧光多肽和白喉毒素A链（DTA）]输送到细胞质中。在氯化铵或EDTA存在的情况下，细胞质传递会被阻断，这表明该过程需要低ph环境和二价阳离子的存在。ph敏感脂质体传递DTA对细胞蛋白质合成的抑制作用比非ph敏感脂质体的抑制作用大几个数量级。通过ph敏感脂质体将DTA传递到细胞质中至少为细胞相关脂质体DTA的0.01%。牛血清白蛋白（BSA）的降解率和ph敏感染料8-羟基-1,3,6-芘-三磺酸盐（HPTS）在ph敏感和非ph敏感脂质体中递送至细胞时的酸化率无显著差异。因此，细胞质递送的效率小于细胞相关脂质体含量的10%，这是这两种检测方法可以检测到的最小差异。根据用于测量脂质体在细胞中含量分布的各种测定，我们得出结论，CHEMS/DOPE脂质体的细胞质递送效率大于0.01%，小于细胞相关脂质体含量的10%。
The intracellular processing of pH-sensitive liposomes composed of cholesterylhemisuccinate (CHEMS) and dioleoylphosphatidylethanolamine (DOPE) by eukaryotic cell lines has been compared to non-pH-sensitive liposomes made of CHEMS and dioleoylphosphatidylcholine (DOPC). The pH-sensitive liposomes can deliver encapsulated fluorescent molecules [calcein, fluoresceinated dextran, fluoresceinated polypeptide, and diphtheria toxin A chain (DTA)] into the cytoplasm. Cytoplasmic delivery can be blocked in the presence of ammonium chloride or EDTA, indicating that the process required a low-pH environment and the presence of divalent cations. Inhibition of cellular protein synthesis by DTA delivery from the pH-sensitive liposome is orders of magnitude greater than from the non-pH-sensitive liposome composition. The delivery of DTA into the cytoplasm by pH-sensitive liposomes is at least 0.01% of cell-associated liposomal DTA. There is no significant difference in the degradation rate of bovine serum albumin (BSA) or the rate of acidification of pH-sensitive dye, 8-hydroxy-1,3,6-pyrene-trisulfonate (HPTS), when delivered to cells in pH-sensitive and non-pH-sensitive liposomes. Thus the efficiency of cytoplasmic delivery is less than 10% of the cell-associated liposome contents, which is the smallest difference that can be detected by these two assays. Based upon the various assays used to measure liposome content disposition in the cell, we conclude that the efficiency of cytoplasmic delivery by the CHEMS/DOPE liposomes is greater than 0.01% and less than 10% of the cell-associated liposomal contents.