Synthesis and Properties of Shape Memory Poly(γ-Benzyl-l-Glutamate)-b-Poly(Propylene Glycol)-b-Poly(γ-Benzyl-l-Glutamate)

Shape memory polymers (SMPs) have attracted much attention as an important class of stimuli-responsive materials for biomedical applications. For SMP-based biomaterials, in addition to suitable shape recovery performances, their mechanical properties, biodegradability, biocompatibility, and sterilizability needs to be considered. Polypeptides can satisfy the requirements outlined above. However, there are few reports on shape memory polypeptides. In this paper, shape memory poly(γ-benzyl-l-glutamate) (PBLG-PPG-PBLG) was synthesized by ring-opening polymerization of γ-benzyl-l-glutamate-N-carboxyanhydrides (BLG-NCA) with poly(propylene glycol) bis(2-aminopropyl ether) as the macroinitiator. 1H Nuclear Magnetic Resonance (NMR) and Fourier-Transform Infrared Spectroscopy (FTIR) were used to characterize the structure of the obtained PBLG-PPG-PBLG. The FTIR analysis showed that PBLG-PPG-PBLG has α-helical and β-sheet structures. PBLG-PPG-PBLG has good shape memory properties, its shape recovery time is less than 120 s, and its shape recovery rate is 100%. In this study, we reported a simple synthetic method to obtain intelligent polypeptide materials, which will be used in many biomedical applications.