Self-Healing Chitosan Hydrogels: Preparation and Rheological Characterization

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Drug Delivery Systems

Background:

• Local drug delivery requires advanced carrier systems with controlled release and self-healing capabilities.
• Chitosan, a biocompatible polysaccharide, offers potential for hydrogel formulation but requires modification for enhanced functionality.
• Pyridoxal 5-phosphate (P5P), the active form of vitamin B6, can act as a crosslinking agent for chitosan.

Purpose of the Study:

• To prepare and characterize chitosan-based self-healing hydrogels for parenteral drug delivery.
• To investigate the influence of precursor ratios and water content on hydrogel properties.
• To evaluate the stability, degradability, and self-healing capacity of the developed hydrogels.

Main Methods:

• Hydrogel preparation using chitosan and pyridoxal 5-phosphate (P5P) with varied precursor ratios and water content.
• Characterization via Nuclear Magnetic Resonance (NMR), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and polarized light microscopy (POM).
• Assessment of hydrogel stability (NMR), morphology (SEM), degradability (pH-dependent studies), and rheological properties (storage/loss moduli, recovery capacity).

Main Results:

• Successful preparation of chitosan-P5P hydrogels with tunable properties based on formulation.
• Demonstrated self-healing ability and good mechanical properties with significant structural recovery capacity.
• Chitosan-P5P hydrogels exhibited pH-dependent degradability and good stability over time.
• NMR, FTIR, XRD, and POM confirmed hydrogelation mechanisms and structure.

Conclusions:

• Chitosan crosslinking with P5P is an effective strategy for creating self-healing hydrogels.
• These hydrogels offer a promising platform for local drug delivery due to their tunable properties, stability, and degradability.
• The developed hydrogels present a favorable balance between mechanical integrity and structural recovery for parenteral administration.