Nanobottles for Controlled Release and Drug Delivery.

Nanobottles refer to colloidal particles with a hollow interior and a single opening in the wall. These unique features make them ideal carriers for the loading, encapsulation, release, and delivery of various types of theranostic agents in an array of biomedical applications. The hollow interior gives them a high loading capacity while the opening enables quick loading and controlled release of the payload(s). More significantly, on-demand release can be readily achieved by adding a stimuli-responsive material as the inner matrix or cork stopper. This progress report begins with an introduction to the general structures and properties of nanobottles, followed by a brief discussion on the methods developed for their fabrication. The use of nanobottles for loading different types of payloads is then showcased, including small-molecule drugs, biomacromolecules, imaging contrast agents, and functional nanoparticles. The strategies explored for controlling the release by varying the size of the opening and/or integrating with a stimuli-responsive material are also highlighted. This paper concludes with some perspectives on future directions for this class of nanomaterials in terms of fabrication, functionalization, and application.