Self-Sorted Pyrene and Ferrocene Functionalized G-Quadruplex Gel: Enhanced Mechanical Strength and Self-Healing via...

Cells, as complex supramolecular systems, integrate multiple bio-supramolecules both independently and synergistically to perform intricate biological functions beyond the scope of individual molecules. While significant progress has been made in understanding the assembly of individual (supra)molecules, the interplay and networking between different (supra)molecular systems in mixtures remain underexplored. In this study, we demonstrate that pyrene (Py) and ferrocene (Fc) conjugated G-quadruplex fibers self-sort in the mixture due to stronger π-π interactions within Py-Py pairs compared to Fc-Py interactions. Additionally, these self-sorted fibers form preferential inter-fiber cross-links through weak interactions between Py and Fc units, as observed through photoluminescence spectroscopy and transmission electron microscopy. This multipoint cross-fiber networking significantly enhances the gelation efficiency as evidenced by a lower MGC, and improves mechanical strength of the mixed gel compared to GPy and GFc gels alone. Furthermore, the mixed gel exhibits rapid self-healing properties, despite the known incompatibility between hydrogel toughness and rapid self-healing capabilities. The tunable mechanical strength and self-healing properties further enable controlled release of bovine serum albumin (BSA) and methyl orange (MO). These findings suggest that weak complementary interactions can be strategically employed to improve the structural and functional properties of supramolecular biomaterials, with probable applications in drug delivery.