Biomimetic design strategy of complex porous structure based on 3D printing Ti-6Al-4V scaffolds for enhanced osseointegration

Ti6Al4V is extensively utilized as orthopedic implants owing to its outstanding biocompatibility and mechanical qualities. However, because Ti6Al4V has a high strength, it is substantially stiffer than natural bone, resulting in stress shielding. To resolve this issue, an effective way is to construct porous titanium alloy scaffolds with adjustable pore size and porosity, and 3D printing technology may be utilized to build complex bespoke forms that fit our specifications. In this work, 3D-printed porous Ti6Al4V scaffolds with imitation of trabecular structure (ITS) and the corresponding regular structure scaffolds (RS), which have three different average pore size (300/400/500 μm), were prepared by selective laser melting technology. A series of in vitro and in vivo experiments were used to assess the scaffolds' physiochemical characteristics, as well as their osseointegration capabilities. The findings revealed that the ITS scaffolds were conducive to cell proliferation and osteogenic differentiation. And the in vivo performance was examined through rabbit tibia bone defect model, the results demonstrated that the ITS scaffolds with average pore size of 400 μm showed the ideal osseointegration potential. Therefore 3D-printed titanium scaffolds with imitation of trabecular structure provides a viable bio-inspired structural and functional design method of titanium alloy orthopedic implants.