title: Titanium alloy surface oxide modulates the conformation of adsorbed fibronectin to enhance its binding to α(5) β(1)  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) increased 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 by hexosaminidase assay). Pretreatments also increased the binding (measured by ELISA) of anti-integrin IgG's to the α(5) and β(1) 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 α(5) β(1) integrins.
authors.affiliation: Hospital for Special Surgery affiliated with the Weill Medical College of Cornell University, New York, NY 10021, USA.
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Rapuano
authors.forename: Jani J E
authors.initials: JJ
authors.lastname: Lee
authors.forename: Daniel E
authors.initials: DE
authors.lastname: MacDonald
mesh_terms: D000327:Adsorption; D000497:Alloys; D000704:Analysis of Variance; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000494:pharmacology*; D005353:Fibronectins / Q000494:pharmacology*; D039081:Integrin alpha5beta1 / Q000502:physiology*; D008669:Metallurgy; D051379:Mice; D016348:Osseointegration / Q000187:drug effects* / Q000502:physiology; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D013499:Surface Properties; D014025:Titanium
chemical_list: D000497:Alloys; D020099:Coated Materials, Biocompatible; D005353:Fibronectins; D039081:Integrin alpha5beta1; C031462:titanium alloy (TiAl6V4); D014025:Titanium