Exposure effects of endotoxin-free titanium-based wear particles to human osteoblasts. (July 2019)

• Record Type: Journal Article
• Authors: Costa, Bruna C.; Alves, Alexandra C.; Toptan, Fatih; Pinto, Ana M.; Grenho, Liliana; Fernandes, Maria H.; Petrovykh, Dmitri Y.; Rocha, Luís A.; Lisboa-Filho, Paulo N.
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 95(2019)
• Page Start: 143
• Page End: 152
• Publication Date: 2019-07
• Subjects: Titanium implants -- Degradation -- Wear particles -- Endotoxins -- Biological effects; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2019.04.003
• Languages: English
• ISSNs: 1751-6161

Abstract

Abstract: Titanium-based materials are widely employed by the biomedical industry in orthopedic and dental implants. However, when placed into the human body, these materials are highly susceptible to degradation processes, such as corrosion, wear, and tribocorrosion. As a consequence, metallic ions or particles (debris) may be released, and although several studies have been conducted in recent years to better understand the effects of their exposure to living cells, a consensual opinion has not yet been obtained. In this work, we produced metallic-based wear particles by tribological tests carried out on Ti-6Al-4V and Ti-15Zr-15Mo alloys. They were posteriorly physicochemically characterized according to their crystal structure, size, morphology, and chemical composition and compared to Ti-6Al-4V commercially available particles. Finally, adsorbed endotoxins were removed (by applying a specific thermal treatment) and endotoxin-free particles were used in cell experiments to evaluate effects of their exposure to human osteoblasts (MG-63 and HOb), namely cell viability/metabolism, proinflammatory cytokine production (IL-6 and PGE2), and susceptibility to internalization processes. Our results indicate that tribologically-obtained wear particles exhibit fundamental differences in terms of size (smaller) and morphology (irregular shapes and rough surfaces) when compared to the commercial ones. Consequently, both Ti-6Al-4V and Ti-15Zr-15Mo particles were able to induce more pronounced effects on cell viability (decrease) and cytokine production (increase) than did Ti-6Al-4V commercial particles. Furthermore, both types of wear particles penetrated osteoblast membranes and were internalized by the cells. Influences on cytokine production by endotoxins were also demonstrated. Graphical abstract: Image 1 Highlights: Titanium implant degradation may release metallic wear debris to human body. Besides triggering inflammatory responses, such debris may impair bone cells. Physicochemical properties of wear debris will influence biological responses. Adsorbed lipopolysaccharides (LPS) may trigger similar effects to wear debris. LPS removal is crucial to correctly evaluate biological effects of implant debris.