Electrochemical Behaviour and Direct Cell Viability Analysis of Hybrid Implants Made of Ti-6Al-4V Lattices Infiltrated with a Bioabsorbable Zn-Based Alloy

Abstract

Biodegradable metals are being developed for biomedical implants or components of implants. Biodegradable zinc-based materials, in particular, have been shown to promote bone regeneration in orthopaedic applications. Here, we investigated the potential of a hybrid Ti-Zn system, comprising a Ti-6Al-4V biostable lattice produced by additive manufacturing (AM) infiltrated by a bioabsorbable Zn-2%Fe alloy, to serve as an osseointegrated implant for dental and orthopaedic applications. The osseointegration of implants can be enhanced by a porous implant structure that facilitates bone ingrowth to achieve superior bonding between the bone tissue and the implant. The hybrid material was evaluated in terms of microstructure and localized chemical composition using scanning and transmission electron microscopy with special attention to the interface between the Ti-based lattice and the biodegradable alloy. The electrochemical behaviour of the Ti-Zn system was analysed in a simulated physiological environment in terms of open circuit potential test and cyclic potentiodynamic polarization. Cytotoxicity was evaluated using direct cell viability tests. The results demonstrate desirable properties of the hybrid Ti-Zn system as a non-cytotoxic material with an acceptable corrosion rate.

Keywords

• osseointegration
• additive manufacturing
• SLM
• lattice
• Ti–6Al–4V
• biodegradable zinc