Characterizing Viscoelastic Modulations in Biopolymer Hydrogels by Coherence-Gated Light Scattering.

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Drug Delivery Systems

Background:

• pH-responsive hydrogels are crucial for controlled drug release.
• Understanding hydrogel structural and mechanical changes during pH-induced swelling/contraction is limited.

Purpose of the Study:

• To investigate the in situ structural and mechanical dynamics of chitosan hydrogels under varying pH conditions.
• To elucidate the viscoelastic modulations during pH-triggered swelling, contraction, and recovery processes.

Main Methods:

• Utilized coherence-gated dynamic light scattering for in situ characterization.
• Monitored nonequilibrium, long-term dynamical processes of chitosan hydrogels at different pH values.

Main Results:

• Chitosan hydrogels exhibit significant viscoelastic modulations during pH-induced swelling/contraction/recovery.
• Identified conditions governing these viscoelastic changes by real-time dynamical monitoring.
• Observed phenomena closely correlate with macroscopic equilibrium states.

Conclusions:

• Coherence-gated dynamic light scattering is effective for in situ characterization of hydrogel dynamics.
• pH-responsive hydrogels undergo complex viscoelastic changes not fully understood previously.
• Findings provide critical insights into hydrogel behavior for advanced drug delivery applications.