Surface-treated 3D printed Ti-6Al-4V scaffolds with enhanced bone regeneration performance: an in vivo study

Guangdao Zhang; Pengyu Zhao; Lin Lin; Limei Qin; Zhiguang Huan; Sander Leeflang; Amir A Zadpoor; Jie Zhou; Lin Wu

doi:10.21037/atm-20-3829

Surface-treated 3D printed Ti-6Al-4V scaffolds with enhanced bone regeneration performance: an in vivo study

Ann Transl Med. 2021 Jan;9(1):39. doi: 10.21037/atm-20-3829.

Authors

Guangdao Zhang¹, Pengyu Zhao^{2

3}, Lin Lin⁴, Limei Qin¹, Zhiguang Huan^{2

3}, Sander Leeflang⁵, Amir A Zadpoor⁵, Jie Zhou⁵, Lin Wu¹

Affiliations

¹ Department of Prosthodontics, School of Stomatology, China Medical University, Shenyang, China.
² State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China.
³ Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, China.
⁴ The First People's Hospital of Shenyang, Shenyang, China.
⁵ Department of Biomechanical Engineering, Delft University of Technology, The Netherlands.

Abstract

Background: Given their highly adjustable and predictable properties, three-dimensional(3D) printed geometrically ordered porous biomaterials offer unique opportunities as orthopedic implants. The performance of such biomaterials is, however, as much a result of the surface properties of the struts as it is of the 3D porous structure. In our previous study, we have investigated the in vitro performances of selective laser melted (SLM) Ti-6Al-4V scaffolds which are surface modified by the bioactive glass (BG) and mesoporous bioactive glass (MBG), respectively. The results demonstrated that such modification enhanced the attachment, proliferation, and differentiation of human bone marrow stromal cells (hBMSC). Here, we take the next step by assessing the therapeutic potential of 3D printed Ti-6Al-4V scaffolds with BG and MBG surface modifications for bone regeneration in a rabbit bone defect model.

Methods: 3D printed Ti-6Al-4V scaffolds with BG and MBG surface modifications were implanted into the femoral condyle of the rabbits, the Ti-6Al-4V scaffolds without surface modification were used as the control. At week 3, 6, and 9 after the implantation, micro-computed tomography (micro-CT) imaging, fluorescence double-labeling to determine the mineral apposition rate (MAR), and histological analysis of non-decalcified sections were performed.

Results: We found significantly higher volumes of regenerated bone, significantly higher values of the relevant bone morphometric parameters, clear signs of bone matrix apposition and maturation, and the evidence of progressed angiogenesis and blood vessel formation in the groups where the bioactive glass was added as a coating, particularly the MGB group.

Conclusions: The MBG coating resulted in enhanced osteoconduction and vascularization in bone defect healing, which was attributed to the release of silicon and calcium ions and the presence of a nano-mesoporous structure on the surface of the MBG specimens.

Keywords: 3D printing; Bone regeneration; bioactive glass; in vivo; mesoporous bioactive glass.