title: [Effects of clinically relevant alumina ceramic, zirconia ceramic and titanium particles of different sizes and concentrations on TNF-alpha release in a human macrophage cell line].
abstract: BACKGROUND
  Aseptic loosening is considered to be the main problem of modern endoprothesis. Tumor necrosis factor alpha (TNFalpha) seems to be the initiator protein of particle disease. The aim of our study was to investigate the TNFalpha response of macrophage like cells (MLC) after stimulation with periprosthetic particles, typically found during revision surgery. For this purpose alumina ceramic (Al2O3), zirconia ceramic (ZrO2) and titanium (Ti) particles of different sizes and concentrations were used. Important was to study the effects of different sizes due to TNFalpha secretion and the comparison of the biological effects of alumina ceramic and titanium.
  
  
  METHODS
  To obtain an TNFalpha profile we used an established macrophage model (Rader et al.) with THP-1 cells (human monocytic cell line). Therefore 106 MLC were incubated with different particle concentrations and sizes for 6 h. The supernatant was then investigated for TNF using ELISA assay.
  
  
  RESULTS
  Ti-particles provoked in both sizes (0.2 microm and 2.5 microm) the greatest TNFalpha response, 8 times and 17 times as high in comparison with control. But substantially more 0.2 microm sized Ti-particles were necessary to get the above mentioned results. Al2O3-particles were not as effective as Ti, but they released fourfold more TNFalpha compared to control. There was no difference in TNFalpha-secretion comparing Al2O3-particles of different sizes (0.6 microm and 2 microm), but a 1000 times greater concentration of the 0.6 microm sized particles were needed. Using Al2O3- and Ti-particles of the same size and concentration, Ti provoked a significant higher TNFalpha response. ZrO2 showed no effects on TNFalpha release.
  
  
  CONCLUSIONS
  Because of our results we recommend ceramic articulating surfaces, which are superior to metal on metal matings ion term of biological reactions. Additionally bigger wear particles should be avoided. Revisionoperation should be done early to avoid huge amount of wear particles and to minimize local osteolysis.
authors.affiliation: Orthopädische Universitätsklinik Essen.
authors.forename: Thomas
authors.initials: T
authors.lastname: Sterner
authors.forename: Norbert
authors.initials: N
authors.lastname: Schütze
authors.forename: Guido
authors.initials: G
authors.lastname: Saxler
authors.forename: Franz
authors.initials: F
authors.lastname: Jakob
authors.forename: Christof P
authors.initials: CP
authors.lastname: Rader
mesh_terms: D000537:Aluminum Oxide / Q000009:adverse effects*; D001672:Biocompatible Materials / Q000009:adverse effects; D002460:Cell Line; D005549:Foreign-Body Reaction / Q000209:etiology* / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D008422:Materials Testing / Q000379:methods; D010316:Particle Size; D014025:Titanium / Q000009:adverse effects*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology* / Q000378:metabolism; D015040:Zirconium / Q000009:adverse effects*
chemical_list: D001672:Biocompatible Materials; D014409:Tumor Necrosis Factor-alpha; D015040:Zirconium; D014025:Titanium; D000537:Aluminum Oxide; C028541:zirconium oxide