title: Microscopic observations and inflammatory cytokine productions of human macrophage phagocytising submicron titanium particles.
abstract: This study was performed to microscopically observe and measure inflammatory cytokine production by human macrophages phagocytosing submicron titanium (Ti) particles. Observations with secondary electron microscopy (SEM), SEM/electron probe microanalysis (EPMA) and transmission electron microscopy (TEM) indicated that macrophages [phorbol-12-myristate-13-acetate (PMA)-differentiated THP-1 cells] at 24 h in culture actively phagocytosed and accumulated submicron Ti particles in intracellular phagosomes, in which refinement of Ti particles occurred. The macrophages were also cultured for 24 h in four media with and without submicron Ti particles and lipopolysaccharide (LPS; components of bacteria). Whilst neither stimulus reduced cell viability, submicron Ti particles and LPS activation independently and synergistically caused the macrophages to produce three inflammatory cytokines (TNF-alpha, IL-1beta and IL-6) at high levels in the culture supernatants. The inflammatory and osteolysis conditions caused by macrophages phagocytosing submicron Ti particles would be worsened by challenge with LPS in patients wearing Ti prostheses.
authors: Department of Dental Materials Science and Technology, Iwate Medical University School of Dentistry, Morioka, Japan. mtaira@iwate-med.ac.jp
authors: Masayuki
authors: M
authors: Taira
authors: Tadayoshi
authors: T
authors: Kagiya
authors: Hidemitsu
authors: H
authors: Harada
authors: Minoru
authors: M
authors: Sasaki
authors: Shigenobu
authors: S
authors: Kimura
authors: Takayuki
authors: T
authors: Narushima
authors: Takashi
authors: T
authors: Nezu
authors: Yoshima
authors: Y
authors: Araki
mesh_terms: D002470:Cell Survival; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism*; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure*; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry; D010014:Osteolysis / Q000378:metabolism; D010316:Particle Size; D010587:Phagocytosis / Q000502:physiology*; D014025:Titanium / Q000737:chemistry / Q000493:pharmacokinetics*
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D014025:Titanium