Dual-Mode Release of IL-4 and TCP from a PGA-SF Core–Shell Electrospinning Scaffold for Enhanced Bone Regeneration through Synergistic Immunoregulation and Osteogenesis

The successful filling of bone defects remains challenging due to the incongruity between bone graft materials and the dynamic process of bone healing. Developing multifunctional materials matching the dynamic process of bone healing offers a viable solution to the current dilemma. Lines of evidence have shown that engineering osteoimmunomodulatory biomaterials can modulate the function of immune cells and thus promote bone regeneration. Herein, we utilized silk fibroin (SF) and polyglycolic acid (PGA) to create a PGA-SF core-shell fibrous scaffold, incorporating interleukin-4 (IL-4) and tricalcium phosphate (TCP) as a codelivery system (PGA/TCP-SF/IL-4), aiming to achieve an initial rapid release of IL-4 and sustained release of TCP. The PGA/TCP-SF/IL-4 scaffold mimicked the native bone structure and showed superior tenacity in the wetting regime.