Ultrasonic combined with barium titanate coating for 3D printing porous titanium alloy (Ti-24Nb-4Zr-7.9Sn) Scaffold Promotes Bone Properties study

Abstract

Large-segment bone defect is very challenging in clinic. At present, the scheme of repairing bone defect with 3D printed porous titanium alloy has attracted more and more attention. However, the piezoelectric effect of human bone can stimulate bone formation, while porous titanium alloys lack electrical activity, which hinders their further application. Therefore, in this study, the porous titanium alloy with low elastic modulus (Ti-24Nb-4Zr-7.9Sn) was used as the mechanical support material, and then the porous titanium alloy was surface-modified with piezoelectric ceramics (BaTiO3), and bionic manufacturing was carried out from the perspective of bioelectric physiology, so as to prepare the artificial bone material with low elastic modulus (Ti-24Nb-4Zr-7.9Sn) with bioelectric activity. Firstly, Micro-CT, mechanical testing machine, water contact angle measuring instrument, X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) were used to characterize the two kinds of stents before and after barium titanate coating. Then the in vitro and in vivo experiments were divided into four groups: porous titanium alloy group (pTi), porous titanium alloy + barium titanate coating group (pTi/BaTiO3), porous titanium alloy + ultrasound group (pTi/LIPUS) and porous titanium alloy + barium titanate coating + ultrasound group (pTi/BaTiO3/LIPUS). The results showed that the ability of adhesion, proliferation and gene expression of bone marrow mesenchymal stem cells on the scaffold surface in pTi/BaTiO3/LIPUS group was significantly higher than that in pTi group, pTi/BaTiO3 group and pTi/LIPUS group. In addition, compared with other groups, the scaffold in pTi/BaTiO3/LIPUS group significantly enhanced osteogenesis and osseointegration at 6 and 12 weeks after being implanted into large radial bone defect in rabbits. Therefore, pTi/BaTiO3/LIPUS has become a promising method to promote bone regeneration in large bone defects in clinical application.