Biodegradable shape-memory block co-polymers for fast self-expandable stents

Area of Science:

• Polymer Chemistry
• Biomaterials Science
• Biomedical Engineering

Background:

• Biodegradable shape-memory polymers (SMPs) are crucial for advanced medical devices like self-expanding stents.
• Current SMPs often lack the rapid deployment and biocompatibility required for optimal clinical performance.

Purpose of the Study:

• To design and synthesize novel biodegradable block co-polymers (PCTBVs) for fast self-expanding stent applications.
• To evaluate the shape-memory properties, mechanical characteristics, and biocompatibility of the synthesized polymers.

Main Methods:

• Synthesis of PCTBVs via reaction of poly(epsilon-caprolactone) (PCL) triol with methylene diphenyl 4,4'-diisocyanate (MDI) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV).
• Characterization using NMR, GPC, DSC, tensile testing, and cyclic thermomechanical tensile testing.
• Biocompatibility assessment through cytotoxicity tests and cell growth experiments.

Main Results:

• PCTBVs exhibited desirable thermal and mechanical properties with a ductile nature.
• PCTBV-25 demonstrated excellent shape-memory recovery (R(f) 94%, R(r) 98%) within 25s at 40°C.
• Stents fabricated from PCTBV-25 showed rapid self-expansion (within 25s at 37°C) and good biocompatibility.

Conclusions:

• The synthesized PCTBV block co-polymers are promising biodegradable SMPs for fast self-expanding stent applications.
• PCTBV-25 offers superior performance compared to existing self-expanding stents in terms of speed and efficiency.
• The material's safety and biocompatibility support its potential clinical translation.