Application of Ti6Al7Nb Alloy for the Manufacture of Biomechanical Functional Structures (BFS) for Custom-Made Bone Implants

Abstract

Unlike conventional manufacturing techniques, additive manufacturing (AM) can form objects of complex shape and geometry in an almost unrestricted manner. AM’s advantages include higher control of local process parameters and a possibility to use two or more various materials during manufacture. In this work, we applied one of AM technologies, selective laser melting, using Ti6Al7Nb alloy to produce biomedical functional structures (BFS) in the form of bone implants. Five types of BFS structures (A1, A2, A3, B, C) were manufactured for the research. The aim of this study was to investigate such technological aspects as architecture, manufacturing methods, process parameters, surface modification, and to compare them with such functional properties such as accuracy, mechanical, and biological in manufactured implants. Initial in vitro studies were performed using osteoblast cell line hFOB 1.19 (ATCC CRL-11372) (American Type Culture Collection). The results of the presented study confirm high applicative potential of AM to produce bone implants of high accuracy and geometric complexity, displaying desired mechanical properties. The experimental tests, as well as geometrical accuracy analysis, showed that the square shaped (A3) BFS structures were characterized by the lowest deviation range and smallestanisotropy of mechanical properties. Moreover, cell culture experiments performed in this study proved that the designed and obtained implant’s internal porosity (A3) enhances the growth of bone cells (osteoblasts) and can obtain predesigned biomechanical characteristics comparable to those of the bone tissue.

Development and biological evaluation of Ti6Al7Nb scaffold implants coated with gentamycin-saturated bacterial cellulose biomaterial

“…The structure of cellulose coating the implants visualized by SEM is presented in Fig 2 . It should be emphasized that as we have proven in our earlier work, the presence of un-sintered metal powder (as seen in Fig 2B ) does not affect the mechanical properties of the implants manufactured [ 30 , 31 ]. Additional data concerning the chemical composition of the manufactured scaffolds are presented in S1 Table .…”

Additive Manufacturing of Customized Metallic Orthopedic Implants: Materials, Structures, and Surface Modifications

“…Therefore, Ni-Ti alloy is also a biocompatible metal material [42]. Considering that Nb has excellent corrosion resistance, chemical inertness, and is harmless to the human body [43], it can be combined with biocompatible Ti to form biocompatible Ti-Nb alloys, for example, Ti-6Al-7Nb [44]. However, Al, V, and Ni are toxic ions and should not be released inside the human body.…”

The effect of geometry on mechanical properties of Ti6Al4V ELI scaffolds manufactured using additive manufacturing technology

“…The use of porous metal structures can effectively eliminate this phenomenon as well. The amount of porosity in the implant is considered to be the crucial factor in promoting successful bone integration with a porous structure [5][6][7]. Open cellular foams and other porous structures are required for bone cell ingrowth to be effective in optimizing biocompatibility [3,8].…”

“…With the use of computed tomography (CT), it is possible to determine the external and internal geometry of the fabricated porous scaffold structures [18,19]. Finally, compression tests enable to simulate the behavior of open-cell structures [6]. The effect of porosity of scaffolds made from various materials (porous titanium, bioglass, HA, TPC/alginate) on bone tissue engineering was described by Zhang [20].…”