Fabrication of a hierarchically porous PMMA/PEI/ZnO osteogenic scaffold and its bone repair efficacy.

Small-sized bone defects can be repaired by self-healing, but it is difficult for the critical-size bone defect. While autologous bone grafting remains the gold standard, its limited availability, however, constrains widespread clinical application. As a promising alternative, artificial bone substitute scaffolds (ABSS) are designed to mimic the extracellular matrix (ECM) microenvironment. Materials and Methods: In this study, we developed a hierarchically porous PMMA/PEI/ZnO scaffold via anti-solvent vapor-induced phase separation (VIPS), replicating the ECM microenvironment of natural bone. Results: The scaffold exhibited: 1) Structural & Mechanical Properties: A cancellous bone-like porous structure with endogenous stress. 2) In vitro, the scaffolds demonstrated excellent biocompatibility, effectively supporting the adhesion, proliferation, and osteogenic differentiation of rBMSCs. 3) In vivo, this performance consequently translated into enhanced repair of critical-size bone defects (CSBDs) in animal models. Conclusions: This scaffold provides a novel approach for bone tissue engineering, combining structural mimicry, bioactivity, and mechanical strength for effective bone regeneration. .