Reversible Stabilization of Vesicles: Redox‐Responsive Polymer Nanocontainers for Intracellular Delivery

We present the self‐assembly of redox‐responsive polymer nanocontainers comprising a cyclodextrin vesicle core and a thin reductively cleavable polymer shell anchored via host–guest recognition on the vesicle surface. The nanocontainers are of uniform size, show high stability, and selectively respond to a mild reductive trigger as revealed by dynamic light scattering, transmission electron microscopy, atomic force microscopy, a quantitative thiol assay, and fluorescence spectroscopy. Live cell imaging experiments demonstrate a specific redox‐responsive release and cytoplasmic delivery of encapsulated hydrophilic payloads, such as the pH‐probe pyranine, and the fungal toxin phalloidin. Our results show the high potential of these stimulus‐responsive nanocontainers for cell biological applications requiring a controlled delivery. Inside and outside the box: A new concept for the self‐assembly of redox‐responsive polymer nanocontainers is based on the stabilization of a cyclodextrin vesicle core by a reductively cleavable polymer shell anchored via host–guest recognition. Controlled release of cargo from the container is possible by a redox trigger.