Porosity optimization confers 3D-printed porous tantalum scaffolds with superior osteogenic capability and biocompatibility over titanium alloys.

OBJECTIVE: This study aimed to compare the osseointegration capacity, biocompatibility, and inflammatory response of 3D-printed tantalum (Ta) and titanium alloy (Ti) scaffolds, with a specific focus on isolating the effect of intrinsic material properties by employing identical pore sizes (200-1000 μm) and porosities (25-95%). METHODS: Ta and Ti scaffolds with controlled pore sizes and porosities were fabricated using 3D printing. Their physicochemical properties and biological performance were systematically evaluated to compare the two materials under architecturally identical conditions. RESULTS: The key finding was that the material composition itself, independent of pore architecture, was a predominant factor governing cellular responses. While both materials supported osteogenesis, Ta scaffolds demonstrated superior osteogenic differentiation, mineralization, and cell adhesion at matched porosities and pore sizes. Gene expression analysis revealed that Ta promoted higher expression of key osteogenic markers (Runx2, Sp7, Bglap), whereas Ti scaffolds showed higher expression of Ctnnb1 and Axin2 and a slightly better anti-inflammatory profile. High porosity (85%, 95%) was generally beneficial for osteogenic activity in both materials. CONCLUSION: The study demonstrates that the intrinsic properties of Ta and Ti significantly influence their biological performance beyond the effects of porosity and pore size. Ta exhibits superior overall osteogenic potential and cell adhesion, making it a promising candidate for orthopedic coatings. This direct comparison under identical topological conditions provides crucial insights for selecting and optimizing base materials for prosthetic implants. TRIAL REGISTRATION: This study is a computer simulation/in vitro cell experiment/data analysis study, and does not involve human or animal experiments.