α-Polyglutamic Acid-Functionalized Polycaprolactone-Based Polyurethane with Integrated Shape Memory Properties and Bioactivity

Shape memory polymers (SMPs) show promise in tissue engineering through programmable deformations, but developing SMPs with simultaneous excellent mechanical performance, shape memory capabilities, and bioactivity remains challenging. We synthesized novel polycaprolactone (PCL)-based shape memory polyurethanes functionalized with α-polyglutamic acid (α-PLGA) side chains (PU-PLGA). These materials exhibited crystallization temperatures of 1.4-2.4 °C and melting temperatures of 40-40.4 °C. The PU-PLGAs demonstrated excellent mechanical properties, with the 2% α-PLGA variant achieving 19.5 MPa tensile strength and 894.9% elongation at break. All PU-PLGAs displayed outstanding shape memory capabilities for complex shape programming. In vitro experiments showed good cell compatibility (>80% viability), with α-PLGA incorporation significantly enhancing rat bone marrow mesenchymal stem cell adhesion, proliferation, and osteogenic differentiation. Conceptual implantation experiments demonstrated PU-PLGA's potential for tissue engineering scaffolds in bone defect repair applications.