A Peptide-Based Mechano-sensitive, Proteolytically Stable Hydrogel with Remarkable Antibacterial Properties

Area of Science:

• Biomaterials Science
• Supramolecular Chemistry
• Nanotechnology

Background:

• Dipeptides are fundamental building blocks in biological systems.
• Hydrogels offer versatile platforms for biomedical applications.
• Developing novel antimicrobial agents is crucial for combating bacterial infections.

Purpose of the Study:

• To synthesize and characterize a long-chain amino acid dipeptide hydrogel.
• To investigate the hydrogel's structural, rheological, and antibacterial properties.
• To explore the potential of this hydrogel as an injectable antimicrobial agent.

Main Methods:

• Hydrogel formation in phosphate buffer (pH 6.0–8.8).
• Characterization using SAXS, PXRD, FT-IR, FE-SEM, HR-TEM, and rheology.
• Antibacterial assays against Escherichia coli and Pseudomonas aeruginosa.
• Biocompatibility assessment with human red blood cells and fibroblast cells.

Main Results:

• The dipeptide forms a pH-responsive hydrogel with a nanofibrillar 3D network.
• The hydrogel exhibits thixotropic behavior, suitable for injection.
• Significant antibacterial activity against Gram-negative bacteria was observed.
• High resistance to proteolytic enzymes and excellent biocompatibility were confirmed.

Conclusions:

• The dipeptide hydrogel is a promising biocompatible and injectable antimicrobial material.
• Its unique properties, including enzyme resistance and thixotropy, offer potential for advanced therapeutic applications.
• Structural modifications to the peptide can significantly alter its gelation and antimicrobial efficacy.