Tunable thermo-responsive hydrogels: synthesis, structural analysis and drug release studies.

Area of Science:

• Polymer Science
• Materials Science
• Biomedical Engineering

Background:

• Thermo-responsive hydrogels exhibit tunable properties with temperature fluctuations.
• Drug delivery systems require precise control over release kinetics.
• Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for pain and inflammation management.

Purpose of the Study:

• To develop and characterize thermo-responsive hydrogel films for controlled NSAID delivery.
• To investigate the influence of hydrogel structure on drug release profiles.
• To evaluate the thermo-responsive behavior and its correlation with structural changes.

Main Methods:

• UV-initiated radical polymerization to synthesize N-isopropylacrylamide-based hydrogel films.
• Infrared spectroscopy for monomer incorporation analysis.
• Calorimetric analyses and equilibrium swelling studies to determine thermo-responsive behavior (LCST).
• Mathematical modeling to analyze 3D-network structure, release kinetics, and diffusional constraints.

Main Results:

• Hydrogel network density depends on feed composition and film thickness.
• Negative thermo-responsive behavior observed with a shrinking/swelling transition between 32.8-36.1°C.
• Mesh size changes significantly with temperature, impacting size-selective permeation and drug delivery.
• Crosslinking degree, film thickness, and loading method influenced drug release profiles at 25 and 40°C.

Conclusions:

• Thermo-responsive hydrogel films are effective delivery devices for NSAIDs like Diclofenac sodium and Naproxen.
• The tunable mesh size and structural properties enable controlled drug release and size-selective permeation.
• Mathematical modeling provides insights into release kinetics and diffusional constraints, aiding in optimizing drug delivery systems.