title: Macrophage cytokine response to particles and lipopolysaccharide in vitro.
abstract: Several investigators have suggested that biologic molecules adsorbed onto particles may play a key role in determining macrophage response. Adsorbed endotoxins (bacterial debris) may be of particular importance since they are widely present exogenously and endogenously and adhere strongly to many materials. Murine-transformed peritoneal macrophages (IC-21) were used in this in vitro study. Secretions of IL-1 beta, TNF alpha, and IL-6 were used as a measure of macrophage response to micron-range particles of high-density polyethylene and Co-Cr-Mo alloy, with and without adsorbed lipopolysaccharide (LPS) endotoxin. Little cytokine secretion was measured in response to particles (and to polypropylene experimental chambers) cleaned with ethanol and saline and not exposed to LPS. The lack of macrophage response to cleaned particles has been reported by others and may help reconcile conflicting reports in the literature. Cytokine secretion levels were high in all cases if the chambers (with or without particles) were exposed to LPS (and rinsed to minimize nonbound LPS). Secretion patterns were different with particles present and for polymer versus metal particles. Overall, these results suggest that (1) adsorbed molecules on material surfaces strongly affect macrophage response and (2) particle surface chemistry and microstructure affect the concentration and configuration of adsorbed molecules, further influencing particle interaction with macrophage surface receptors.
authors.affiliation: University of Tennessee-Campbell Clinic, Department of Orthopaedic Surgery, 956 Court Avenue, Room A302, Memphis, Tennessee 38163, USA.
authors.forename: A U
authors.initials: AU
authors.lastname: Daniels
authors.forename: F H
authors.initials: FH
authors.lastname: Barnes
authors.forename: S J
authors.initials: SJ
authors.lastname: Charlebois
authors.forename: R A
authors.initials: RA
authors.lastname: Smith
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D002461:Cell Line, Transformed; D002858:Chromium Alloys; D016207:Cytokines / Q000096:biosynthesis*; D007375:Interleukin-1 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000494:pharmacology*; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000276:immunology*; D051379:Mice; D011095:Polyethylenes; D013499:Surface Properties; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D001672:Biocompatible Materials; D002858:Chromium Alloys; D016207:Cytokines; D007375:Interleukin-1; D015850:Interleukin-6; D008070:Lipopolysaccharides; D011095:Polyethylenes; D014409:Tumor Necrosis Factor-alpha