Graphene oxide/sodium alginate/silk fibroin extracellular matrix-like sponge for acellular and growth factor-free...

Bone defects, accompanied by delayed union or nonunion, pose considerable challenges in orthopedics, necessitating urgent resolution. Traditional bone tissue engineering materials typically require the integration of biomaterials with exogenous biological signals, such as cells or cytokines. However, these materials frequently suffer from poor biocompatibility, limited bone repair efficacy, complex preparation processes, and high costs, which hinder their ability to meet clinical translational demands. In this study, we successfully developed a material-centric graphene oxide/sodium alginate/silk fibroin(GO/SA/SF) sponge with an extracellular matrix-like(ECM-like) structure, employing the simple freeze-drying technique and utilizing widely accessible materials. Invitro experiments demonstrated that the sponge exhibited excellent biomimetic ECM properties and outstanding biosafety, significantly enhancing the osteogenesis of bone marrow mesenchymal stem cells (BMSCs) and the angiogenesis of endothelial cells(ECs). Being readily implanted into rat skull defects, the sponge favors bone repair through enhancing spatial osteogenesis-angiogenesis coupling in vivo. Bioinformatics analysis revealed that the sponge activated the canonical TGF-β signaling pathway, effectively promoting the osteogenic differentiation of rBMSCs. This material-centric ECM-like sponge eliminates the need for the integration of additional biological signals, offering low cost-effectiveness and streamlined manufacturing advantages. The excellent biocompatibility, high porosity, and degradability facilitate the wide application possible. Such characteristics offer a novel strategy to accelerate the clinical translation of bone tissue engineering materials for bone regeneration.