A spermine-responsive supramolecular chemotherapy system constructed from a water-soluble pillar[5]arene and a diphenylanthracene-containing amphiphile for precise chemotherapy.

Stimuli-responsive supramolecular chemotherapy, particularly in response to cancer biomarkers, has emerged as a promising strategy to overcome the limitations associated with traditional chemotherapy. Spermine (SPM) is known to be overexpressed in certain cancers. In this study, we introduced a novel supramolecular chemotherapy system triggered by SPM. The system featured pyridine salts of a diphenylanthracene derivative (PyEn) and a complementary water-soluble pillar[5]arene (WP5C5) with long alkyl chains. The diphenylanthracene unit of PyEn is effectively encapsulated within the long alkyl chains of WP5C5, resulting in a substantial reduction in the cytotoxicity of PyEn towards normal cells. The therapeutic effect of PyEn is selectively triggered intracellularly through SPM, leading to the endosomal release of PyEn and concurrent in situ cytotoxicity. This supramolecular chemotherapy system exhibits notable tumor inhibition against SPM-overexpressed cancers with reduced side effects on normal tissues. The supramolecular strategy for intracellular activation provides a novel tool with potential applications in chemotherapeutic interventions, offering enhanced selectivity and reduced cytotoxicity to normal cells.

pH/ROS dual stimuli-responsive anionic flexible supramolecular organic frameworks for synergistic therapy.

Supramolecular organic frameworks (SOFs) have emerged as a promising class of organic porous materials with vast potential as nanocarriers for combination therapy. Here, we successfully construct an anionic flexible supramolecular organic framework (TPP-SOF) by leveraging multiple host-guest interactions. TPP-SOF is fabricated by the hierarchical orthogonal assembly between anionic water-soluble dimacrocyclic host (P5CD), porphyrin photosensitizers (TPP), and ROS-sensitive thioketal linked adamantane dimer (Ada-S-Ada). TPP-SOF exhibits pH-dependent activation of 1O2 production, which further facilitates the cleavage of Ada-S-Ada linker and promotes the disintegration of the framework. Moreover, leveraging electrostatic and hydrophobic interactions, the anionic TPP-SOF serves as an effective platform for loading cationic photosensitizer IR780 and chemotherapeutic prodrug PhenPt(IV), leading to the formation of supramolecular nanoparticles (IR780/Pt@TPP-SOF) for synergistic therapy. The obtained nanoparticles exhibit good stability, efficient generation of 1O2, and photothermal performance. In vitro and in vivo studies indicate that IR780/Pt@TPP-SOF exhibits remarkable synergistic chemo/PDT/PTT effects under 808 and 660 nm light irradiation. This study showcases a deep insight for the development of SOFs and a new approach for delivering cationic drugs and constructing synergistic combination therapy systems. STATEMENT OF SIGNIFICANCE: In this work, a pH/ROS-responsive anionic flexible supramolecular organic framework, TPP-SOF, was innovatively designed by the hierarchical orthogonal assembly, to co-deliver cationic photosensitizer IR780 and prodrug PhenPt(IV) for synergistic cancer therapy. The drug-loaded TPP-SOF is termed IR780/Pt@TPP-SOF, in which the photoactivity of porphyrin within TPP-SOF could be activated under acidic conditions, the 1O2 generated by the photosensitizers could break the thioketal bonds in Ada-S-Ada, leading to the disassembly of the framework and releasing the drugs. This supramolecular drug delivery system displays good biocompatibility and exhibits remarkable synergistic chemo/PDT/PTT effects.