Ti6Al4V biomimetic scaffolds for bone tissue engineering: Fabrication, biomechanics and osseointegration

The design of porous structure that mimic trabecular bone is an effective method for optimizing the elastic modulus and osseointegration properties of titanium alloy implants. However, there is no consensus on which structure is best. In this study, we fabricated 24 different types of Ti6Al4V trabecular bone scaffolds with varying porosity and average pore size using Voronoi algorithm and selective laser melting technology. The biomechanics and osseointegration properties were studied by mechanical tests, computational fluid dynamics, cell and animal experiments. Our results showed that with an increase of porosity and average pore size, the scaffold's yield strength, ultimate strength, elastic modulus and shear stress exhibited an overall decreasing trend while the permeability and nutrient transport improved. Cell experiments showed that reducing the average pore size enhanced the adhesion and proliferation of MC3T3-E1 cells when the porosity was constant. Animal experiments showed that the scaffold with 65% porosity and 550 μm pore size had the most significant new bone formation effect. Based on our research results, we concluded that a porous structure design with 65% porosity and an average pore size of 550 μm, resembling bone trabecular, had the most significant effect on enhancing the comprehensive performance of titanium alloy implants.