Responsive Hyaluronic Acid-Ethylacrylamide Microgels Fabricated Using Microfluidics Technique

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Microfluidics

Background:

• Responsive microgels are valuable tools for studying interactions between polyelectrolytes and charged species like peptides and proteins.
• Hyaluronic acid (HA) is a biocompatible polysaccharide with potential for microgel applications.

Purpose of the Study:

• To develop a microfluidics-based method for synthesizing highly responsive, covalently crosslinked hyaluronic acid microgels.
• To investigate how varying HA concentration and degree of modification affects microgel properties and responsiveness.

Main Methods:

• Microfluidic synthesis of ethylacrylamide-functionalized sodium hyaluronate (HA) microgels.
• ¹H NMR spectroscopy to determine the degree of HA modification.
• Light microscopy and confocal laser scanning microscopy to assess microgel responsiveness, permeability, and partitioning behavior.

Main Results:

• Spherical microgels with diameters ranging from 100 to 500 µm were successfully synthesized.
• Microgel responsivity was tunable by adjusting the degree of HA modification and HA concentration.
• Microgels exhibited full permeability to FITC-dextrans (4-250 kDa), with partitioning decreasing as probe molecular weight increased.

Conclusions:

• The microfluidics approach enables the production of tunable, responsive HA microgels.
• These microgels are suitable for probing interactions with charged biomolecules due to their controlled permeability.
• The observed partitioning behavior aligns with theoretical models for homogeneous gel networks.