A phenazine-linked π-conjugated covalent organic framework for conjugation-driven drug loading

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Nanotechnology

Background:

• π-conjugated covalent organic frameworks (COFs) are advanced porous materials with potential in drug delivery.
• Harnessing conjugation-affinity correlations in COFs is crucial for targeted therapeutic applications.
• Designing COFs with specific π-stacking and pore environments is key for optimizing guest interactions.

Purpose of the Study:

• To synthesize and characterize a novel phenazine-linked π-conjugated COF (TU-32).
• To investigate the COF's structural properties, specifically its atypical AB stacking mode.
• To evaluate the COF's drug loading capacity and selectivity based on drug molecule conjugation.

Main Methods:

• Synthesis of TU-32 using 2,7-di-tert-butylpyrene-4,5,9,10-tetraone and a phenazine-forming amine.
• Characterization using techniques to confirm structure and π-conjugation.
• Drug loading experiments with 5-fluorouracil, isoniazid, and captopril to determine capacity and affinity.

Main Results:

• TU-32 exhibits an atypical AB stacking mode, suppressing interlayer π-stacking and enhancing structural regularity.
• The COF demonstrates selective drug loading, with higher capacity for conjugated molecules like 5-fluorouracil (56 wt%) and isoniazid (54 wt%).
• Lower loading was observed for the non-conjugated drug captopril (36 wt%), confirming conjugation-driven affinity.

Conclusions:

• Precise engineering of π-conjugated COFs via phenazine linkages enables tunable, conjugation-driven guest affinity.
• The study highlights the importance of π-π interactions in drug encapsulation within porous frameworks.
• TU-32 offers a design blueprint for next-generation conjugated porous materials for precision drug delivery.