Azido-Functionalized Polyurethane Designed for Making Tunable Elastomers by Click Chemistry.

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Polyurethanes are widely used biomaterials in biomedical engineering.
• Current methods for polyurethane modification can involve toxic reagents or postmodification steps.

Purpose of the Study:

• To develop a novel azido-functionalized polyurethane prepolymer.
• To create stable porous elastomers using click chemistry, avoiding toxic polyisocyanates.
• To investigate the tunable mechanical properties and biocompatibility of the resulting elastomers.

Main Methods:

• Synthesis of an azido-functionalized polyurethane prepolymer.
• Cross-linking via click chemistry using the prepolymer to form porous and compact elastomers.
• Mechanical property testing (Young's modulus, strain at break, cyclic deformation).
• Assessment of material stability in basic solution and in vivo biocompatibility via subcutaneous implantation in mice.

Main Results:

• The prepolymer readily formed stable porous elastomers through click chemistry.
• Mechanical properties, including Young's modulus (0.52–2.02 MPa for porous, up to 28.8 MPa for compact), were tunable.
• Elastomers exhibited high strain at break (150%) and excellent fatigue resistance (1000 cycles).
• The material demonstrated stability in basic solution and good in vivo biocompatibility with minimal inflammatory response.

Conclusions:

• A novel, easily synthesized azido-functionalized polyurethane prepolymer enables the creation of tunable, high-performance elastomers.
• The click chemistry approach avoids toxic reagents and allows for property modulation.
• The material's mechanical properties, stability, and biocompatibility suggest its potential for biomedical device components.