Aggregation-Induced Emission Featured Supramolecular Tubisomes for Imaging-Guided Drug Delivery

Polymeric cylinders, a fascinating type of nanostructures with high surface area, internal volume and rigidity, have been exploited as novel drug delivery vehicles over the past decade. However, it's still an open challenge to afford cylindrical nanostructures using polymeric building blocks via traditional self-assembly processes. Herein, we report a hierarchical self-assembly strategy of preparing cylindrical aggregates (tubisomes) from an amphiphilic supramolecular bottlebrush polymer in which a cyclic peptide nanotube is employed as the noncovalent backbone. Additionally, an aggregation-induced emission (AIE) effect was introduced into the tubisomes to endow them with excellent fluorescent properties. Intriguingly, by encapsulating with the anticancer drug doxorubicin (DOX), both the fluorescence of tubisome and DOX can be quenched due to the energy transfer relay (ETR) effect. The release of DOX can induce the interruption of the ETR effect and recover the silenced fluorescence, thereby permitting the in-situ imaging of drug release. The AIE-featured supramolecular tubisomes reported here provide an alternative approach for fabricating cylindrical polymeric nanostructures and holds great potential for imaging-guided drug delivery.