A multifunctional supramolecular hydrogel: preparation, properties and molecular assembly

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Drug Delivery Systems

Background:

• Supramolecular hydrogels offer versatile platforms for advanced applications.
• Designing hydrogels with controlled self-assembly is crucial for targeted functionalities.
• Gemini surfactants and aromatic compounds are key building blocks for novel gelators.

Purpose of the Study:

• To design and construct a novel supramolecular hydrogel using a cationic gemini surfactant (AGC16) and an anionic aromatic compound (NTS).
• To characterize the self-assembly mechanism, structural properties, and gelation behavior of the AGC16/NTS hydrogel.
• To evaluate the hydrogel's potential as a multifunctional drug delivery system for hydrophobic and aromatic drugs.

Main Methods:

• Rheological measurements and Differential Scanning Calorimetry (DSC) to determine gelation temperature and properties.
• Spectroscopic techniques (UV-Vis, fluorescence, 1H NMR) and microscopy (Cryo-SEM, TEM) to elucidate self-assembly and structure.
• X-ray diffraction to analyze the ordered structure and proposed self-assembly model.
• Drug encapsulation and release studies using curcumin (hydrophobic) and naproxen sodium (aromatic).

Main Results:

• The AGC16/NTS hydrogel formed below 57 °C, driven by electrostatic, hydrophobic, and π-π interactions.
• Self-assembly resulted in a 3D network structure of intertwined one-dimensional fibers.
• Spectroscopic and diffraction data supported a proposed self-assembly model.
• The hydrogel successfully encapsulated curcumin via hydrophobic interactions and naproxen sodium via π-π stacking.
• Sustained drug release was observed for both model drugs.

Conclusions:

• A novel supramolecular hydrogel (AGC16/NTS) was successfully synthesized through molecular self-assembly.
• The hydrogel exhibits a unique 3D network structure driven by multiple non-covalent interactions.
• The material demonstrates excellent potential as a multifunctional drug delivery carrier with sustained release capabilities.