In Vitro and In Vivo Evaluation of Biodegradation and Osteoinductive Properties of Tantalum and Zinc Co‐Doped β‐TCP Porous Bioceramic Scaffolds

Abstract β‐Tricalcium phosphate (β‐TCP) ceramics suffer from inadequate mechanical strength and uncontrolled degradation in critical bone defect repair. To address this, Tantalum/Zinc co‐doped β‐TCP （Ta/Zn‐β‐TCP） porous ceramics are developed via a novel microwave‐ultrasound hydrothermal method. Physicochemical analyses confirms successful incorporation of Ta⁵⁺ (2.46 mol%) and Zn 2 ⁺ (2.35 mol%) into the β‐TCP lattice without phase alteration, inducing bidirectional lattice distortion that enhances compressive strength by 90% (10.72 ± 0.31 MPa and pure β‐TCP: 5.65 ± 0.20 MPa) while maintaining optimal porosity (63.7 ± 1.2%). In vitro, Ta⁵⁺ formed a passivation layer regulating Ca 2 ⁺ release (degradation rate: 5.96% at 28 days and 9.8% for pure β‐TCP), while Zn 2 ⁺ enriched PO 4 3− ions to accelerate biomimetic mineralization. The co‐doped ceramic significantly upregulates osteogenic genes (Runx2: ↑180%, BMP2: ↑230%, OCN: ↑190%) in rat bone marrow mesenchymal stem cells (rBMSCs. In a rat calvarial critical‐sized defect model, micro‐CT and histology revealed superior bone regeneration with Ta/Zn‐β‐TCP (BV/TV: 45.98% at 12 weeks), outperforming pure β‐TCP (22.27%) and commercial Novabone (45S5 bioglass‐based) (41.67%). The material's triple synergy mechanical reinforcement, immunomodulation, and coupled angiogenesis‐osteogenesis, establishes it as a promising candidate for non‐load bearing bone repair.