Supramolecular Isoguanosine Assemblies Form Hydrogels with Excellent Long-Term Stability

Area of Science:

• Supramolecular chemistry
• Materials science
• Biomaterials

Background:

• Nucleoside-based hydrogels are promising for drug delivery and regenerative medicine.
• The stability of these hydrogels is crucial for their application.
• Guanosine hydrogels exhibit limited stability.

Purpose of the Study:

• To investigate the hydrogel formation and stability of isoguanosine and its derivatives.
• To compare the properties of isoguanosine hydrogels with those of guanosine hydrogels.
• To explore the potential of isoguanosine hydrogels in drug delivery.

Main Methods:

• Hydrogel formation in alkali metal salt solutions.
• Rheological measurements to assess gel stability.
• Scanning Electron Microscopy (SEM) for structural analysis.
• Drug loading and release studies.

Main Results:

• Isoguanosine, 2'-deoxyisoguanosine, and 2'-deoxy-2'-fluororibuoisoguanosine form stable hydrogels.
• Isoguanosine hydrogels demonstrate significantly higher stability (15x) compared to guanosine hydrogels.
• Gels are stable over a broad pH range (3-10) and at physiological sodium ion concentrations.
• SEM revealed self-assembly into interconnected helical fibers for isoguanosine, contrasting with guanosine's discrete ribbons.
• Isoguanosine gels exhibit excellent loading and release capabilities for small molecules.

Conclusions:

• Isoguanosine-based hydrogels offer superior long-term stability and structural integrity compared to guanosine hydrogels.
• The self-assembly into helical fibers contributes to the enhanced mechanical properties of isoguanosine gels.
• These findings highlight the potential of isoguanosine hydrogels as advanced biomaterials for drug delivery and regenerative medicine.