Chitosan/agarose hydrogels: cooperative properties and microfluidic preparation

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Drug Delivery

Background:

• Composite biopolymer hydrogels offer tunable properties for biomedical applications.
• Chitosan and agarose are natural polymers with inherent biocompatibility and biodegradability.
• Developing materials with dual responsiveness (pH and temperature) is crucial for controlled release systems.

Purpose of the Study:

• To prepare and characterize composite hydrogels from chitosan and agarose with dual pH and temperature sensitivity.
• To investigate the mechanical properties and stability of these composite hydrogels.
• To evaluate the drug release profile of an anticancer drug (5-Fluorouracil) from the hydrogels.

Main Methods:

• Composite hydrogels were synthesized using chitosan and varying concentrations of agarose.
• Mechanical properties were assessed by measuring the elastic modulus.
• Drug release studies were conducted using 5-Fluorouracil at different pH values.
• Microfluidic emulsification was employed to create composite microgels with controlled dimensions.

Main Results:

• Elastic modulus increased with agarose concentration, reaching 1 kPa at 2% (w/v) agarose.
• Composite gels showed enhanced stability in acidic solutions compared to pure agarose gels.
• Drug release of 5-Fluorouracil was pH-dependent, with lower release at acidic pH (33% at pH 5.2 vs. 50% at pH 7.4).
• Microgels with controlled sizes (18-42 μm) and narrow size distribution were successfully fabricated.

Conclusions:

• Chitosan-agarose composite hydrogels exhibit dual pH and temperature-responsive properties.
• These hydrogels demonstrate tunable mechanical strength and improved stability.
• The pH-dependent drug release profile highlights their potential for targeted anticancer drug delivery.
• Microfluidic techniques enable the production of well-defined composite microgels for advanced applications.