Solvent-free synthesis of biostable segmented polyurethane shape memory polymers for biomedical applications

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Materials Engineering

Background:

• Biostable shape memory polymers are crucial for controlled shape recovery in physiological conditions.
• Simple, scalable, and biocompatible synthesis methods are essential for commercialization.

Purpose of the Study:

• To synthesize biostable, cytocompatible shape memory polymers with tunable properties via a solvent-free method.
• To evaluate the impact of hard segment content and processing on polymer characteristics.
• To assess the potential for creating fibrous scaffolds for biomedical applications.

Main Methods:

• Solvent-free synthesis of shape memory polymers with varying hard segment content.
• Characterization of surface chemistry, thermomechanical properties, shape memory behavior, and biostability.
• Investigation of annealing and solvent casting effects.
• Comparison of fiber formation with solvent-based methods.

Main Results:

• Polymers exhibited high glass transition temperatures (>50 °C), high shape fixity (73-80%), and shape recovery (93-95%).
• Minimal degradation (<5% mass loss) was observed in oxidative and hydrolytic media, with stable shape recovery after 40 days.
• Solvent-free synthesis yielded polymers with higher molecular weight and crystallinity, enabling superior fibrous scaffolds with enhanced mechanical and shape memory properties.

Conclusions:

• A solvent-free method successfully produced biostable, cytocompatible shape memory polyurethanes with tunable properties.
• These polymers demonstrate excellent stability and shape memory performance, suitable for implantation and scaffold fabrication.
• The developed materials offer potential for advanced biomedical devices and drug delivery systems.