Shape-Memory Biopolymers Based on -Sheet Structures of Polyalanine Segments Inspired by Spider Silks

The molecular structural design learned from natural materials enables synthetic polymers with desirable and unique features to be fabricated. Inspired by spider silks, short-chain polyalanine (PA) is introduced into multiblock biopolymers with poly(epsilon-caprolactone) segments via a coupling reaction. As a result, PA segments in biopolymers form similar -sheet crystals to that of natural spidroins. These new biopolymers are found to exhibit nearly complete shape recovery and high shape fixity, along with significantly improved thermal stability due to the strong -sheet structures as netpoints. This work provides new insight for the design of novel shape-memory polymers with potential use in biomedical applications.