title: Measurement and removal of adherent endotoxin from titanium particles and implant surfaces.
abstract: Aseptic loosening is thought to be due primarily to osteolysis induced by cytokines and prostaglandins that are produced in response to implant-derived wear particles. Because endotoxin has many of the same effects as have been reported for wear particles, we hypothesized that adherent endotoxin may be responsible for the biological responses induced by wear particles. We demonstrated the presence of significant levels of adherent endotoxin on commonly used preparations of titanium particles as well as on titanium and titanium-alloy implant surfaces. In contrast, supernatants obtained by centrifugation of particle suspensions contained approximately 1% as much endotoxin as did the particles. Therefore, it is erroneous to assume that particles do not contain endotoxin on the basis of data that it cannot be detected in their supernatants or filtrates. These results emphasize the importance of considering the potential role of adherent endotoxin when examining the in vitro effects of wear particles and the in vivo performance of orthopaedic implants. We also developed a protocol that removed more than 99.94% of the adherent endotoxin from the titanium particles without detectably affecting their size or shape. The removal of adherent endotoxin will allow comparison of the biological responses induced by particles with or without adherent endotoxin.
authors.affiliation: Department of Orthopaedics, Case Western Reserve University, Cleveland, Ohio 44106-5000, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Ragab
authors.forename: R
authors.initials: R
authors.lastname: Van De Motter
authors.forename: S A
authors.initials: SA
authors.lastname: Lavish
authors.forename: V M
authors.initials: VM
authors.lastname: Goldberg
authors.forename: J T
authors.initials: JT
authors.lastname: Ninomiya
authors.forename: C R
authors.initials: CR
authors.lastname: Carlin
authors.forename: E M
authors.initials: EM
authors.lastname: Greenfield
mesh_terms: D004731:Endotoxins / Q000032:analysis* / Q000302:isolation & purification; D019637:Orthopedic Procedures; D019736:Prostheses and Implants; D014025:Titanium
chemical_list: D004731:Endotoxins; D014025:Titanium