Activation of human leukocytes on tantalum trabecular metal in comparison to commonly used orthopedic metal implant materials

Abstract

We analyzed leukocyte functions and cytokine response of human leukocytes toward porous tantalum foam biomaterial (Trabecular Metaltrade mark, TM) in comparison to equally sized solid orthopedic metal implant materials (pure titanium, titanium alloy, stainless steel, pure tantalum, and tantalum coated stainless steel). Isolated peripheral blood mononuclear cells (PBMC) and polymorphonuclear neutrophil leukocytes (PMN) were cocultured with equally sized metallic test discs for 24 h. Supernatants were analyzed for cytokine content by enzyme-linked immunosorbent assay. Compared to the other used test materials there was a significant increase in the release of IL (interleukin)-1ra and IL-8 from PMN, and of IL-1ra, IL-6, and TNF-alpha from PBMC in response to the TM material. The cytokine release correlated with surface roughness of the materials. In contrast, the release of IL-2 was not induced showing that mainly myeloid leukocytes were activated. In addition, supernatants of these leukocyte/material interaction (conditioned media, CM) were subjected to whole blood cell function assays (phagocytosis, chemotaxis, bacterial killing). There was a significant increase in the phagocytotic capacity of leukocytes in the presence of TM-conditioned media. The chemotactic response of leukocytes toward TM-conditioned media was significantly higher compared to CM obtained from other test materials. Furthermore, the bactericidal capacity of whole blood was enhanced in the presence of TM-conditioned media. These results indicate that leukocyte activation at the surface of TM material induces a microenvironment, which may enhance local host defense mechanisms.

Additively manufactured porous tantalum implants

“…Today, TM is the most commonly used biomaterial containing Ta in orthopedics [30][31][32][33][34][35][36]. Over 250 publications and 800,000 surgeries worldwide [37] illustrate its non-toxic and osteoconductive behavior, but without actual proof of outperforming other commonly used materials such as surgical grade 5 Ti-6Al-4V [38][39][40][41][42]. It has proven bone ingrowth both in animal studies [29,[43][44][45] and retrievals from clinical cases [46,47], 5 although some publications mention issues like implant failure and the brittle deformation behavior of TM [48][49][50].…”

Tribological behavior of a Ta-based coating on a Co–Cr–Mo alloy

“…The coating is formed by tantalum carbides and its structure is a multilayer (TaC or Ta 2 C) or a single layer (TaC), depending on the carbon content of the alloy and on the treatment temperatures. It is well known that tantalum (Ta) has excellent mechanical and corrosion resistance [42,43], as well as biocompatibility, and it is suitable for cell adhesion, proliferation and differentiation [44][45][46][47]. Ta and its compounds (oxides, nitrides or carbides) have been already used, as protective coatings, in order to improve mechanical and wear resistance.…”

Can Tantalum Cones Provide Fixation in Complex Revision Knee Arthroplasty?

“…Histologic studies indicate porous tantalum presents a surface for osteoblast expression and, ultimately, the growth of native bone into the metal [5,11,23]. Data also suggest that tantalum surfaces increase host white blood cell activation and lower bacterial fixation [21,22], possibly decreasing the risk of infection. These laboratory studies suggest tantalum cones may provide long-term biologic fixation with a lower risk of infection when used in vivo in complex revision knee arthroplasties.…”