Chitosan-Based Thermal-Coagulation Hydrogel System Driven by Multiple Interactions: Oxidation-Induced Fast Gelation...

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• The chitosan/β-glycerophosphate (CS/β-GP) system is a promising hydrogel for biomedical applications but suffers from poor mechanical properties, high β-GP concentration requirements, and slow gelation.
• These limitations hinder its widespread use in tissue repair and regenerative medicine.

Purpose of the Study:

• To enhance the thermal-coagulation properties of the CS/β-GP system by modifying chitosan with catechol groups (CS-C).
• To investigate the impact of catechol modification on the physicochemical properties, gelation kinetics, and mechanical performance of the hydrogel.
• To explore the potential of the modified hydrogel in biomedical applications, including antimicrobial activity and biocompatibility.

Main Methods:

• Synthesis of catechol-chitosan (CS-C) with varying grafting rates.
• Characterization of CS-C solutions, including pH and pKa measurements.
• Evaluation of gelation time and required β-GP concentration for hydrogel formation.
• Assessment of hydrogel mechanical properties (stiffness) and stability.
• Testing of antimicrobial activity and biocompatibility of the CS-C/β-GP hydrogels.

Main Results:

• Catechol modification significantly reduced the amino group content, affecting solution pH and pKa.
• Gelation time and required β-GP concentration were substantially decreased.
• The CS-C/β-GP hydrogel exhibited a 10-fold increase in stiffness compared to unmodified CS/β-GP.
• Rapid gelation (1-2 minutes) and a lower β-GP content (2-6 wt %) were achieved.
• The modified hydrogel demonstrated favorable antimicrobial and biocompatibility profiles.

Conclusions:

• Catechol modification effectively overcomes the limitations of the traditional CS/β-GP system.
• The enhanced CS-C/β-GP hydrogel offers superior mechanical properties, rapid gelation, and reduced β-GP requirements.
• This study elucidates the thermal-coagulation mechanism of modified chitosan systems, paving the way for advanced chitosan-based biomaterials in medicine and tissue engineering.