Effect of Pore Size on the Physicochemical Properties and Osteogenesis of Ti6Al4V Porous Scaffolds with Bionic Structure

Ti6Al4V is widely used in implants in the fields of orthopedics and dentistry due to its high compressive strength and good biocompatibility. Nevertheless, Ti6Al4V has a certain degree of biological inertness and the elastic modulus of Ti6Al4V is much higher than the cortex and trabecular bone. In this study, we designed and printed a new type of pore size Ti6Al4V with like-trabecular structure scaffold (the pore size is 800/900/1000 μm, named P8/P9/P10, respectively) with electron beam melting (EBM). Its elastic modulus, compressive strength, and other physical and chemical properties, as well as cell adhesion, proliferation, and differentiation ability and in vitro biological properties were studied. The physical and chemical performance test results showed that as the pore size increased, the surface wettability increased and the elastic modulus decreased. As the pore size increased, F-actin and alkaline phosphatase (ALP) increased significantly, and osteogenesis-related genes including BMP2, OCN, RUNX2, and ALP were upregulated significantly. The reason may be that the components on the Ti6Al4V pore size may have an influence on intracellular signal conversion and then change the mode of cell proliferation and diffusion. In summary, the like-trabecular porous structure can effectively reduce the elastic modulus of metal materials, thereby avoiding stress concentration and promoting the adhesion and proliferation of osteoblasts. Porous materials with larger pores are more conducive to the proliferation and differentiation of osteoblasts. The irregular porous Ti6Al4V scaffold prepared by the EBM technology has good mechanical properties and the potential to promote adhesion, proliferation, and differentiation of osteoblasts, and has the possibility of application in the field of implantation.