pH-sensitive liposomes mediate cytoplasmic delivery of encapsulated macromolecules

FEBS Lett. 1985 Jan 1;179(1):148-54. doi: 10.1016/0014-5793(85)80210-6.

Abstract

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 membrane-impermeant 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 less than 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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cell Line
  • Chlorocebus aethiops
  • Dextrans
  • Drug Stability
  • Fluorescein-5-isothiocyanate* / analogs & derivatives*
  • Fluoresceins
  • Fluorescent Dyes
  • Hydrogen-Ion Concentration
  • Indicators and Reagents
  • Kidney
  • Kinetics
  • Liposomes*
  • Phosphatidylcholines
  • Phosphatidylserines

Substances

  • Dextrans
  • Fluoresceins
  • Fluorescent Dyes
  • Indicators and Reagents
  • Liposomes
  • Phosphatidylcholines
  • Phosphatidylserines
  • fluorescein isothiocyanate dextran
  • Fluorescein-5-isothiocyanate
  • fluorexon