Self-assembly Of Cucurbit[8]uril-based Supra-amphiphiles Into Photo-responsive Functional Vesicles

Cucurbit[n]uril(CB[n])are a set of macrocyclic compounds which are formed by n glycoluril molecules linked with 2n methylene bridges.The special bonding mode between the glycoluril units endows the cucur-bit[n]uril with very stable structures.Furthermore,CB[n] have unique hydrophobic cavities and can selectively encapsulate specific guest molecules through hydrophobic interaction,hydrogen-bonding interaction(e.g.FGG peptide)or charge-dipole interaction(e.g.methyl viologen)with carbony-fringed portals of their cavities' entrance.The synergistic effect of noncovalent interactions between CB[n] and their guests makes the complexes more stable than other types of host-guest ones.CB[8] has a large cavity that can hold two guest molecules,which is not common in synthetic macrocyclic molecules.The diversity,binding strength,and multi-stimuli responsiveness of CB[8] complexes make them a fascinating building blocks to intensively study the assembly behavior and the property of CB[8]-based materials.Here,CB[8] related work that contains two sections is presented as follow: 1.Self-assembly of CB[8]-based supra-amphiphiles into photo-responsive vesicles.CB[8] has a large cavity that can hold MV and trans-azobenzene to form a ternary complex.The charge transfer interaction between MV and trans-azobenzene enables the formation of stable complex that can be dissociated under 365 nm UV illumination through the isomerization between trans-and cis-azobenzene.A novel photoswitchable supra-amphiphile that contains a hydrophilic N-methyl-N'-maleimido viologen(MMV)CB[8] moiety and a hydrophobic azobenzene derivative with three dodecyl tails was constructed based on optically controlled complexation and dissociation of MV-azobenzene CB[8].We used rhodamine B and 5(6)-carboxyfluorescein to as models tested the photo stimuli-responsive property and property of drug loading and releasing.2.Cucurbit[8]uril-based supramolecular vesicles: a multi-functional system for photo-responsive and targeted drug delivery.Here,the above-mentioned vesicles were functionalized with target molecule(e.g.Irgd and hyaluronic acid)on its surface via a click reaction between maleimide and thiol groups to realize rapid transmembrane movement,targeted drug delivery,and controlled release.We also studied the mechanism of the vesicles entering cell membrane,selectivity of tumor cell and pharmacodynamic evaluation at cellular level and confirmed the endocytic mechanism.