Synthesis of a new water-soluble hexacarboxylated tribenzotriquinacene derivative and its competitive host-guest interaction for drug delivery

A new water-soluble hexacarboxylated tribenzotriquinacene derivative ( ) was synthesized and used as a supramolecular drug carrier to load the model anticancer drugs dimethyl viologen ( ) and doxorubicin ( ) via host-guest interactions. The drugs could be effectively released by spermine ( ), a molecule overexpressed in cancer cells, through host-guest competitive substitution since has a stronger binding affinity toward than and . The host-guest interactions of the complexes of with , and were investigated by NMR spectroscopy and fluorescence spectroscopy. The association stoichiometry of the complexes of with , , and was found to be 1:1 with association constants of = (7.67 ± 0.34) × 10 M , = (6.81 ± 0.33) × 10 M , and = (5.09 ± 0.98) × 10 M , respectively. The competitive substitution process was visualized by NMR titration. This novel TBTQ-based host-guest drug delivery system may have potential use in supramolecular chemotherapy.