title: Human monocyte response to retrieved polymethylmethacrylate particles.
abstract: The purpose of this study was to compare retrieved polymethylmethacrylate (PMMA) particles from failed total hip arthroplasties in terms of size, shape, and the response of human monocytes with commercially available particles. PMMA particles were isolated from peri-implant tissues of five failed cemented total hip arthroplasties using tissue digestion and a sucrose density gradient technique. Prepolymerized cement powder and those from which barium sulfate had been removed were examined for comparison. After exposure of peripheral human monocytes to PMMA particles, tumor necrosis factor-alpha and interleukin-6 in medium were measured by using enzyme-linked immunosorbent assays. Image analysis revealed that retrieved particles were larger (retrieved: 1.24 microm; prepolymerized cement powder: 0.83 microm; barium sulfate-free powder: 0.87 microm) and were more irregular in shape and rougher than commercially available particles. Cytokine release was increased by all PMMA particle species. However, commercially available PMMA particles stimulated the release of necrosis factor-alpha and interleukin-6 more strongly than did retrieved particles at very high doses. The observed difference in monocyte response might be due to the volume of the challenged particles. Another possible reason for the difference might be alteration of the surface chemistry of particles in situ and the difference in surface morphology between them.
authors.affiliation: Department of Orthopaedic Surgery, Osaka City University Medical School, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan. m-gucci@juno.ocn.ne.jp
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Miyaguchi
authors.forename: Akio
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Iwaki
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Ohashi
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kadoya
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Yamano
mesh_terms: D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D009000:Monocytes / Q000378:metabolism*; D019904:Polymethyl Methacrylate; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D019904:Polymethyl Methacrylate