title: Polymethylmethacrylate particles stimulate bone resorption of mature osteoclasts in vitro.
abstract: BACKGROUND
  Interaction between wear particle debris and the cells at the implant-bone interface is an important contributory factor to periprosthetic bone loss seen in arthroplasties.
  
  
  METHODS
  To investigate the effect of this particle-induced response on different stages of osteoclast maturation, polymethylmethacrylate (PMMA) particles were added to a murine osteoclastogenic bone marrow cell culture system at either day 0, day 4, or day 8 of culture, which represented PMMA particle stimulation of precursor osteoclasts, mature osteoclasts, or end-stage osteoclasts, respectively. The number of TRAP-posi-tive multinucleate cells (MNCs) and the degree of bone resorption in culture were measured
  
  
  RESULTS
  Treatment of precursor osteoclasts with PMMA particles resulted in a statistically significant increase in TRAP-positive MNCs that persisted for 4 days, but there was no significant increase in bone resorption. Addition of particles to mature osteoclasts resulted in a significant increase in the number of TRAP-positive MNCs that lasted for 8 days, and also a significant increase in bone resorption. Treatment of end-stage osteoclasts with PMMA particles did not result in an increased number of TRAP-positive MNCs and there was no increase in bone resorption.
  
  
  CONCLUSIONS
  Treatment of mature osteoclasts with PMMA particles resulted in an elevated number of TRAP-positive cells. This persisted over a longer period of time than at the other stages of osteoclast development, and there was also a greater increase in bone resorption.
authors.affiliation: The Hospital for Special Surgery, New York, NY, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Benjamin F
authors.initials: BF
authors.lastname: Ricciardi
authors.forename: Xu
authors.initials: X
authors.lastname: Yang
authors.forename: Yuexian
authors.initials: Y
authors.lastname: Shi
authors.forename: Nancy P
authors.initials: NP
authors.lastname: Camacho
authors.forename: Mathias G
authors.initials: MG
authors.lastname: Bostrom
mesh_terms: D000818:Animals; D001843:Bone Cements / Q000494:pharmacology*; D001862:Bone Resorption / Q000139:chemically induced / Q000473:pathology; D018929:Cell Culture Techniques; D017077:Culture Media, Conditioned; D051379:Mice; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D010316:Particle Size; D019904:Polymethyl Methacrylate / Q000494:pharmacology*
chemical_list: D001843:Bone Cements; D017077:Culture Media, Conditioned; D019904:Polymethyl Methacrylate