Dual-functional gyroid MgO/HA bioceramic scaffolds via DLP-SPS for accelerated osteogenesis and angiogenesis in bone repair

Developing bone scaffolds with biomimetic architecture and bioactive signaling is essential for effective orthopedic repair. In this study, 16.6 wt% MgO incorporated hydroxyapatite (MgO/HA) scaffolds with a Gyroid Triply Periodic Minimal Surface (TPMS) architecture were fabricated using a multi-stage route combining Digital Light Processing (DLP) 3D printing and Spark Plasma Sintering (SPS). The resulting scaffolds maintained ∼60% porosity and exhibited an increase in compressive strength (7.27 MPa) compared to HA (4.24 MPa). The incorporation of MgO led to an increase in the degradation rate, facilitating the sustained release of bioactive Mg²⁺ ions. In vitro biological evaluations demonstrated a potent multi-lineage cellular response: the scaffolds enhanced rat mesenchymal stem cell (rMSC) proliferation and upregulated key osteogenic markers (RUNX2, ALP, and OCN), while simultaneously stimulating human umbilical vein endothelial cells (HUVECs) by significantly upregulating angiogenic gene expressions (VEGF and Ang-1). These results indicate that the combination of MgO doping and TPMS architecture successfully establishes a robust osteogenesis-angiogenesis coupling effect alongside optimized mechanical performance, providing a highly promising candidate platform for patient-specific bone tissue engineering.