Mechanically Robust, Shape-Memory, and Personalized Silk Fibroin/Magnesium Composite Scaffolds induce in situ Irregular Bone Regeneration

Abstract The regeneration of critical-sized bone defects, especially for irregular shapes, remain a clinical challenge. Although various biomaterials were developed to enhance bone regeneration, the limitations on the shape-adaptive capacity, the complexity of clinical operation and the unsatisfied osteogenic bioactivity restricted greatly their clinical application. Herein, we construct a mechanically robust, tailorable and blood-responsive shape memory effect silk fibroin/ Magnesium (SF/MgO) composite scaffold, which can quickly match irregular defects by easily trimming and achieve good interface integration. The SF/MgO composite scaffold exhibits excellent mechanical performance and structure retention during the degradation process, which significantly improved the supporting ability in defective site. In addition, the SF/MgO composite scaffolds can achieve shape recovery very quickly either under water or blood conditions. This scaffold promotes cell proliferation, adhesion, migration of osteoblasts, and osteogenic differentiation of BMSCs in vitro. Subcutaneous implantation results confirmed that with suitable content SF/MgO composite scaffold exhibited good histocompatibility, low foreign body reactions, and as well as significant ectopic mineralization and angiogenesis. Meanwhile, the SF/MgO composite scaffold markedly promote in situ robust bone regeneration of cranial defect. This bioactive shape memory porous scaffolds provides a new design idea for minimally invasive clinical-size irregular bone regeneration.