Titanium alloy surface oxide modulates the conformation of adsorbed fibronectin to enhance its binding to α₅β₁ integrins in osteoblasts

Abstract

Our laboratory has previously demonstrated that heat (600 °C) or radiofrequency plasma glow discharge (RFGD) pretreatment of a titanium alloy (Ti6Al4V) increases the net-negative charge of the alloy’s surface oxide and the attachment of osteoblastic cells to adsorbed fibronectin. The purpose of the current study was to investigate the biological mechanism by which these surface pretreatments enhance the capacity of fibronectin to stimulate osteoblastic cell attachment. Each pretreatment was found to increase the binding (measured by ELISA) of a monoclonal anti-fibronectin Ig to the central integrin-binding domain of adsorbed fibronectin, and to increase the antibody’s inhibition of osteogenic cell attachment (measured using the hexosaminidase assay). Pretreatments also increased the binding (measured by ELISA) of anti-integrin Igs to the α5 and β1 integrin subunits that became attached to fibronectin during cell incubation. These findings suggest that negatively charged surface oxides of Ti6Al4V cause conformational changes in fibronectin that increase the availability of its integrin-binding domain to α5β1 integrins.

Porous Titanium‐6 Aluminum‐4 Vanadium Cage Has Better Osseointegration and Less Micromotion Than a Poly‐Ether‐Ether‐Ketone Cage in Sheep Vertebral Fusion

“…Recently, Ti alloy has been found to provide a highly favorable surface for osteoblast adhesion and osteogenic differentiation. Rapuano et al demonstrated that Ti alloy can form a superficial oxide layer that absorbs fibronectin and promotes osteoblast attachment and osteointegration through binding of adsorbed fibronectin to surface-expressed osteoblast integrins (17). Moreover, OlivaresNavarrete et al found that culture of human osteoblast-like cells on Ti-6Al-4V can lead to enhanced osteogenic differentiation compared with PEEK (15).…”

“…Recent studies showed that the titanium alloy (Titanium-6 Aluminum-4 Vanadium [Ti-6Al-4V]) can promote better osteoblast adhesion and differentiation in vitro than PEEK (15)(16)(17). Thus, Ti-6Al-4V could be a better material for cage devices, with greater potential for osteointegration.…”

Advancements in three-dimensional titanium alloy mesh scaffolds fabricated by electron beam melting for biomedical devices: mechanical and biological aspects

“…Titanium alloy was observed to provide a highly favorable surface for osteoblast adhesion and osteogenic differentiation. In another study, it was shown that the oxide layer adsorbed fibronectin promoted osteoblast attachment and osteointegration through binding of adsorbed fibronectin to surface-expressed osteoblast integrins [104]. Studies also reported the influence of surface nanotopography on the enhanced expression of osteogenic markers [105][106][107].…”

Additive manufactured metallic implants for orthopaedic applications

“…Ti alloy has been observed to provide a favourable surface for osteoblast adhesion and osteogenic differentiation. It can form a superficial oxide layer that promoted osteoblast attachment through binding of adsorbed fibronectin to surface-expressed integrins [22]. Another study has shown that the culture of osteoblastlike cells on Ti-6Al-4V alloy substrate could promote osteoblastic maturation by creating an osteogenic environment that contains bone morphogenetic proteins and could enhance bone formation [23].…”