Selective laser melting (SLM), Porous Ta scaffold, Structure-property relationship, Fatigue resistance performance, Bone defect, Mining engineering. Metallurgy, TN1-997

Porous tantalum (Ta) has exhibited exceptional biocompatibility and osseointegration capacity as an advanced orthopedic implant material. This study employs selective laser melting (SLM) to fabricate porous Ta scaffolds with controlled porosities (65 %, 75 %, 85 %, 90 %), systematically investigating their structure-property relationship for bone tissue engineering applications. Results demonstrate that SLM-fabricated porous Ta scaffolds possess biomechanical properties comparable to native bone tissue while maintaining superior fatigue resistance. In vitro assessments confirm the scaffolds’ excellent cytocompatibility, with porosity levels significantly affecting MC3T3-E1 pre-osteoblast differentiation. Notably, scaffolds with 75 % porosity induced optimal osteogenic differentiation, as evidenced by enhanced mineralization markers. Porous Ta scaffolds with 75 % porosity were implanted in rabbit femoral condyles for bone defect repair. Quantitative analysis revealed progressive osseointegration, with bone ingrowth area ratios measuring 7.4 ± 3.4 % at 4 weeks and 21.7 ± 5.5 % at 12 weeks post-implantation. In parallel large-animal trials, 75 % porosity scaffolds were successfully deployed in goat femoral defects. After 12 weeks of implantation, VG staining confirmed distinct bone ingrowth within the scaffolds, while mechanical evaluation demonstrated sustained load-bearing capacity sufficient for femoral defect stabilization.