Issue 43, 2018

The great escape: how cationic polyplexes overcome the endosomal barrier

Abstract

The targeted and efficiency-oriented delivery of (therapeutic) nucleic acids raises hope for successful gene therapy, i.e., for the local and individual treatment of acquired and inherited genetic disorders. Despite promising achievements in the field of polymer-mediated gene delivery, the efficiency of the non-viral vectors remains orders of magnitude lower than viral-mediated ones. Several obstacles on the molecular and cellular level along the gene delivery process were identified, starting from the design and formulation of the nano-sized carriers up to the targeted release to their site of action. In particular, the efficient escape from endo-lysosomal compartments was demonstrated to be a major barrier and its exact mechanism still remains unclear. Different hypotheses and theories of the endosomal escape were postulated. The most popular one is the so-called “proton sponge” hypothesis, claiming an escape by rupture of the endosome through osmotic swelling. It was the first effort to explain the excellent transfection efficiency of poly(ethylene imine). Moreover, it was thought that a unique mechanism based on the ability to capture protons and to buffer the endosomal pH is the basis of endosomal escape. Recent theories deal with the direct interaction of the cationic polyplex or free polymer with the exoplasmic lipid leaflet causing membrane destabilization, permeability or polymer-supported nanoscale hole formation. Both escape strategies are more related to viral-mediated escape compared to the “proton sponge” effect. This review addresses the different endosomal release theories and highlights their key mechanism.

Graphical abstract: The great escape: how cationic polyplexes overcome the endosomal barrier

Article information

Article type
Review Article
Submitted
12 4月 2018
Accepted
11 9月 2018
First published
13 9月 2018

J. Mater. Chem. B, 2018,6, 6904-6918

The great escape: how cationic polyplexes overcome the endosomal barrier

T. Bus, A. Traeger and U. S. Schubert, J. Mater. Chem. B, 2018, 6, 6904 DOI: 10.1039/C8TB00967H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements