Dynamic light scattering size distribution, ζ-potential data, and fluorescence spectra

The water-soluble tribenzotriquinacene-based hexacarboxylic acid ammonium salt, TBTQ-C6, acts as the host component (H) forming host-guest complexes with tetraphenylethylene (TPE)-functionalized monotopic and tetratopic quaternary ammonium derivatives, G1 and G2, to yield supra-amphiphiles. These supra-amphiphiles self-assemble to form pH-responsive fluorescent vesicles, which have allowed us to capitalize on the aggregation-induced emission (AIE) effect for imaging-guided drug delivery systems. These systems exhibit efficient drug loading and pH-responsive delivery capabilities. Upon encapsulation of the anticancer drug doxorubicin (DOX), both the TPE and DOX chromophores undergo dual-fluorescence deactivation due to the energy transfer relay (ETR) effect. Under acidic conditions, the release of DOX interrupts the ETR effect, resulting in the fluorescence recovery of TPE fluorogens and DOX, allowing for real-time visual monitoring of the drug release process. Cytotoxicity experiments confirmed the low toxicity of the unloaded vectors to normal cells, while the DOX-loaded vectors were found to significantly enhance the anticancer activity of DOX against cancer cells in vitro. The AIE-featured supramolecular vesicles presented in this research hold great potential for imaging-guided drug delivery systems.

Methods
Dynamic light scattering (DLS) and ζ-potential were measured on a Zetasizer Nano S90 particle size analyzer (Malvern Instruments, England) at room temperature. UV-vis spectra were taken on a UV-1800 UV-vis spectrophotometer (Shimadzu, Japan) and fluorescence spectra were recorded on a F97pro fluorescence spectrophotometer (Lengguang, China) fluorescence spectrophotometer.