Biocompatible shape-memory poly(propylene carbonate)/silk fibroin blend with body temperature responsiveness.

The high value-added medical applications surely represent the leading edge of the shape-memory materials (SMPs) field. Herein, the biomedical SMPs were easily prepared incorporating silk fibroin (SF) into poly(propylene carbonate) (PPC) through directly melt blending. Based on the intrinsic glass transition of PPC at ∼37 °C, the blends showed a body temperature responsiveness without a complex procedure for adjusting the switching temperature. By varying the SF content, the blend exhibited tunable shape-memory effects (SME), with a first enhancing but then worsening shape recoverability and a stable and excellent shape fixity. And the blend with 3 wt% SF achieved the best SME, enabling an efficient shape reconfiguration under a 37 °C water bath. It was revealed that SF acted as physical cross-links to connect the PPC chains forming a shape-memory network, thus can well retard irreversible the chain slipping of PPC, leading to the improvement of recoverability. Moreover, the results obtained from cell compatibility testing showed the huge application potential of this material in the biomedical field. This work proposed a facile preparation strategy for developing biocompatible body heat actuated shape-memory materials.