As novel stimuli-responsive biomaterials, shape memory polymers (SMPs) have been used in bone defect repair. The 3D shape of these biomaterials can be switched between initial and temporary states under external stimuli, such as temperature changes and water contact, making them suitable for tightly filling bone defects and advantageous over traditional materials featuring shape mismatch and complicated implantation. In addition, modified SMPs can be used as porous bone tissue engineering scaffolds to load various bioactive factors and stem cells for new bone formation. Recently, SMPs have shown promising prospects in minimal invasiveness, repairing irregular bone defects, and promoting bone defect regeneration. This review will discuss the current progresses of SMPs in bone tissue engineering, including their mechanism, biological effects, and performance optimization.
