In vitro behavior of bioactive hybrid implant composed of additively manufactured titanium alloy lattice infiltrated with Mg-based alloy

We have developed a novel bioactive hybrid metallic implant that integrates the beneficial characteristics of a permanent matrix and a biodegradable substance. Such a combination may generate a material system that evolves into a porous structure within weeks to months following implantation and can be used to form strong interfacial bonding and osseointegration for orthopedic and dental applications. Presently, traditional technol-ogies such as casting, powder metallurgy and plastic forming have limited ability to produce the complex bioactive implant structures that are required in practical applications. The present study aimed to develop an innovative bioactive Ti-Mg (BTiMg) hybrid system using a Ti-lattice (Ti-6Al-4 V) produced by an additive manufacturing (AM) process, in combination with a new Mg-based alloy (Mg-2.4%Nd-0.6%Y -0.3%Zr) as a biodegradable filling material. We evaluated the in-vitro behavior of the BTiMg system in a simulated physio-logical environment, along with cytotoxicity assessment. The microstructure was evaluated by scanning electron microscopy and X-ray diffraction, mechanical properties were examined in terms of compressive strength, environmental performance analysis was conducted by electrochemical testing using potentiodynamic polari-zation and impedance spectroscopy (EIS), and cytotoxicity characteristics were assessed by indirect cell viability analysis. The results demonstrated the feasibility to produce geometrically complex implants by AM technology, as well as the strength and non-cytotoxic effects of the BTiMg system. Benefits included a relatively high ultimate compressive strength (UCS) and a high yield point (YP), along with an adequate cell viability response in the range between 70 and 120%.

Automated summary

The study developed a novel bioactive hybrid metallic implant by combining a permanent matrix with a biodegradable substance, resulting in a porous structure that forms strong interfacial bonding and osseointegration in vivo. Benefits included the ability to produce complex implant structures and high strength with non-cytotoxic effects.