Combined treatment with a pH-sensitive fusogenic peptide and cationic lipids achieves enhanced cytosolic delivery of exosomes

Sci Rep. 2015 May 26:5:10112. doi: 10.1038/srep10112.


Exosomes, which are approximately 100 nm vesicles secreted by cells, have been studied with respect to cell-to-cell communication, disease diagnosis, and intracellular delivery. The cellular uptake of exosomes occurs by endocytosis; however, the cytosolic release efficiency of encapsulated molecules inside cells is low. To address this issue, here we demonstrate a simple technique for enhancing the cellular uptake and cytosolic release of exosomes by combining a pH-sensitive fusogenic peptide for the fusion of endosomal and exosomal membranes inside cells. This method stimulates the efficient cytosolic release of the exosomal contents with cationic lipids that act as a "glue" to support cellular uptake. Using this simple combined technique, the effective cellular uptake and cytosolic release of an artificially encapsulated dextran macromolecule (70 kDa) in exosomes are achieved, and a marked improvement in bioactivity is attained with the artificially encapsulated ribosome-inactivating protein saporin. Our method will contribute to many biological research fields, including the assessment of the activities of exosomal contents and the development of candidate tools enabling intracellular visualisation and cellular regulation for future therapeutic applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cations / chemistry
  • Cytosol / metabolism*
  • Dextrans / chemistry
  • Dextrans / metabolism
  • Endocytosis
  • Exosomes / metabolism*
  • HeLa Cells
  • Humans
  • Hydrogen-Ion Concentration
  • Lipids / chemistry*
  • Microscopy, Confocal
  • Molecular Sequence Data
  • Peptides / chemistry
  • Peptides / metabolism*
  • Ribosome Inactivating Proteins, Type 1 / chemistry
  • Ribosome Inactivating Proteins, Type 1 / metabolism
  • Saporins
  • Tetraspanin 30 / genetics
  • Tetraspanin 30 / metabolism


  • Cations
  • Dextrans
  • Lipids
  • Peptides
  • Ribosome Inactivating Proteins, Type 1
  • Tetraspanin 30
  • GALA peptide
  • Saporins