Biodegradable shape-memory polymers exhibiting sharp thermal transitions and controlled drug release.

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials

Background:

• Biodegradable polymers are crucial for sustainable materials.
• Shape-memory polymers offer unique stimulus-responsive properties.
• Controlled drug delivery systems require advanced material platforms.

Purpose of the Study:

• To synthesize and characterize novel biodegradable shape-memory polymer networks.
• To evaluate the thermal, mechanical, and shape-memory properties of these networks.
• To develop and assess a theophylline-loaded drug delivery system based on these polymers.

Main Methods:

• Star-shaped branched oligo(ε-caprolactone) (bOCL) was cross-linked with hexamethylene diisocyanate.
• Differential scanning calorimetry, tensile testing, and polarized optical microscopy were used for characterization.
• Thermomechanical tensile experiments quantified shape-memory performance (strain fixity and recovery rates).

Main Results:

• Shape-memory polymer networks achieved high strain fixity (>97%) and recovery (>99%).
• Lower degree of polymerization (DP=10) networks showed enhanced temperature-sensitive recovery (90% within 2°C range).
• Theophylline-loaded networks demonstrated sustained release over one month without burst release.

Conclusions:

• Biodegradable shape-memory polymer networks offer excellent shape-memory performance.
• These materials are promising for applications requiring tunable, temperature-triggered shape recovery.
• The developed theophylline-loaded polymer is a viable model for controlled drug delivery devices.