Synthesis of second-generation self-assembling Gemini Amphiphilic Pseudopeptides

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Biomaterials

Background:

• Gemini Amphiphilic Pseudopeptides (GAPs) exhibit tunable self-assembly based on structural modifications.
• Controlling self-assembly in aqueous media is crucial for developing advanced functional materials.

Purpose of the Study:

• To investigate the impact of a flexible, nitrogen-containing linker on the self-assembly properties of bipodal and tripodal GAPs.
• To enhance the formation of self-assembled structures in aqueous environments for potential biomedical applications.

Main Methods:

• Synthesis and characterization of modified GAPs.
• Morphological analysis using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Atomic Force Microscopy (AFM).
• Solution structure analysis via Nuclear Magnetic Resonance (NMR), UV-Vis, Circular Dichroism (CD), Fourier-Transform Infrared (FT-IR), and fluorescence spectroscopy.

Main Results:

• Self-assembly into vesicles or fibers is dependent on medium polarity and pH.
• The protonation of the nitrogen atom in the linker plays a critical role in the self-assembly mechanism.
• Modified GAPs demonstrated improved vesicle formation in aqueous media across various pH and ionic strengths.

Conclusions:

• The incorporation of a central nitrogen atom in the linker significantly improves the self-assembly of GAPs in water.
• The pH-dependent protonation of the linker is key to controlling self-assembly morphology.
• These GAPs show potential for use in drug delivery and other biomedical applications due to their enhanced aqueous self-assembly properties.