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pH‐sensitive liposomes mediate cytoplasmic delivery of encapsulated macromolecules
Author(s) -
Straubinger Robert M.,
Düzgünes Nejat,
Papahadjopoulos Demetrios
Publication year - 1985
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(85)80210-6
Subject(s) - liposome , vesicle , calcein , phosphatidylethanolamine , phosphatidylcholine , cytoplasm , chemistry , phosphatidylserine , intracellular , monensin , biophysics , endocytosis , oleic acid , biochemistry , macromolecule , membrane , phospholipid , biology , cell
Negatively charged liposomes are endocytosed by the coated vesicle system and accumulate in acidic intracellular vesicles. Liposomes that become unstable at acidic pH improve cytoplasmic delivery of membraneimpermeant macromolecules such as calcein (CAL) and FITC dextran (18 or 40 kDa). Oleic acid (OA): phosphatidylethanolamine (PE) (3:7 mole ratio) liposomes become permeable to CAL at pH < 7.0. Control liposomes of phosphatidylserine : PE or OA : phosphatidylcholine are stable at pH 4–8. OA:PE liposomes promote cytoplasmic delivery of encapsulated CAL to CV‐1 cells, as evidenced by the emergence of diffuse, cytoplasmic CAL fluorescence. Delivery requires metabolic energy and is partially inhibited by chloroquine or monensin, which raise the pH of intracellular vesicles.