Osseointegration of an innovative functionally gradient biomimetic scaffold based on Voronoi-Tessellation for the design of orthopaedic implants

The geometry and pore size of porous structures have a significant impact on osseointegration in orthopaedic implant design. This study introduced a new approach to designing biomimetic scaffolds using the Voronoi-Tessellation algorithm and additive manufacturing techniques. The results showed that the gradient structure designed by this method had decreasing thickness and pore size from top to bottom. Specimens printed using Selective Laser Sintering technology had higher structural thicknesses (20–57%) and lower porosities (24–42%) than CAD models, with an effective elastic modulus within the range of natural bone at 606–1522 MPa. Osteogenic differentiation experiments with bone mesenchymal stem cells in vitro showed stable cell proliferation and viability, as well as higher ALP activity and calcium nodule detection compared to the blank group. Animal experiments suggested that groups with larger pore sizes exhibited superior performance in promoting bone growth in vivo based on BV/TV and Tb.N measurement.