Wear particles from automotive friction brake pads of various sizes, morphology, and chemical composition are significant contributors towards particulate matter. Knowledge concerning the potential adverse effects following inhalation exposure to brake wear debris is limited. Our aim was, therefore, to generate brake wear particles released from commercial low-metallic and non-asbestos organic automotive brake pads used in mid-size passenger cars by a full-scale brake dynamometer with an environmental chamber simulating urban driving and to deduce their potential hazard in vitro. The collected fractions were analysed using scanning electron microscopy via energy-dispersive X-ray spectroscopy (SEM-EDS) and Raman microspectroscopy. The biological impact of the samples was investigated using a human 3D multicellular model consisting of human epithelial cells (A549) and human primary immune cells (macrophages and dendritic cells) mimicking the human epithelial tissue barrier. The viability, morphology, oxidative stress, and (pro-)inflammatory response of the cells were assessed following 24 h exposure to ~ 12, ~ 24, and ~ 48 µg/cm2 of non-airborne samples and to ~ 3.7 µg/cm2 of different brake wear size fractions (2-4, 1-2, and 0.25-1 µm) applying a pseudo-air-liquid interface approach. Brake wear debris with low-metallic formula does not induce any adverse biological effects to the in vitro lung multicellular model. Brake wear particles from non-asbestos organic formulated pads, however, induced increased (pro-)inflammatory mediator release from the same in vitro system. The latter finding can be attributed to the different particle compositions, specifically the presence of anatase.
- MeSH
- biologické modely * MeSH
- buňky A549 MeSH
- cytokiny metabolismus MeSH
- dendritické buňky účinky léků metabolismus ultrastruktura MeSH
- kokultivační techniky MeSH
- látky znečišťující vzduch toxicita MeSH
- lidé MeSH
- makrofágy účinky léků metabolismus ultrastruktura MeSH
- motorová vozidla MeSH
- oxidační stres účinky léků MeSH
- pevné částice toxicita MeSH
- plíce účinky léků metabolismus patologie MeSH
- povrchové vlastnosti MeSH
- velikost částic MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE OF THE STUDY This study deals with the possibilities and application of immunohistochemical methods to detect mast and dendritic cells in periprosthetic tissues in patients with aseptically loosened total joint replacements of the knee and hip. The purpose of the study was to quantify and characterize the distribution of mast and dendritic cells in the examined samples and to study the statistically significant relations between the aforementioned cell populations and selected parameters characterizing the patients, implants or tissue response. Based on the proved findings, a possible relation between mast and dendritic cells and histomorphological patterns of aseptic loosening and the benefit of the applied immunohistochemical methods was evaluated. MATERIAL AND METHODS Periprosthetic tissues from a total of 31 patients (17 patients after a revision surgery of hip prosthesis, 14 patients after a revision surgery of knee prosthesis) were examined. The collected samples were processed according to the standard protocol for the purposes of histological and immunochemical examination. Antibodies against tryptase and CD117 were used for immunohistochemical detection of mast cells. Dendritic cells were detected by means of S100 and CD1a antibodies. Quantification of both the cell populations was carried out by optical microscopy in 20 high power fields at 400-times magnification. From among the applied methods we picked the more sensitive one for statistical evaluation. It was tryptase in the case of mast cells and S100 in the case of dendritic cells. RESULTS Mast and dendritic cells were mostly distributed dispersively in periprosthetic tissues; however, they also occurred in groups perivasally or near necrotic parts. The examined samples showed the presence of 60 mast cells and 50 dendritic cells on average. The increased density of mast and dendritic cells was associated with polypously formed pseudosynovium and cement fixation of prostheses; this relation was statistically significant. It was impossible to prove the correlation between the quantity of the observed cell populations and the nature and the number of the observed particles because wear particles were present dispersely in all the samples. Another statistically significant relation to the type of material or implant fixation or other examined histomorphological patterns was not proved. A strong density of mast cells with a minimum presence of dendritic cells was observed in the control patient group. DISCUSSION The differences in density of S100 positive dendritic cells between the control and examined group of patients can be caused by the activation of dendritic cells by exogenous or endogenous pathways of immune processes going on after the implantation of endoprosthesis. The statistically significant interrelation of mast cells, polypously formed pseudosynovium and cement wear particles can be explained at least in part as a tissue reaction induced by cement particles. CONCLUSIONS We proved the presence of two immunologically significant cell populations in periprosthetic tissues. The said findings indicate a conclusion of significant functional participation of mast and dendritic cells in pathogenesis of aseptic loosening and periprosthetic osteolysis. Nevertheless, this will have to be proved in another way and with the use of another method. Key words:dendritic cells, mast cells, aseptic loosening, total joint replacement, immune reaction, adverse reaction.
- MeSH
- antigeny CD1 imunologie MeSH
- dendritické buňky imunologie ultrastruktura MeSH
- kolenní kloub mikrobiologie patologie chirurgie MeSH
- kyčelní kloub mikrobiologie patologie chirurgie MeSH
- kyčelní protézy škodlivé účinky mikrobiologie MeSH
- lidé MeSH
- mastocyty imunologie ultrastruktura MeSH
- mikroskopie přístrojové vybavení MeSH
- proteiny S100 imunologie MeSH
- protézy kolene škodlivé účinky mikrobiologie MeSH
- protoonkogenní proteiny c-kit imunologie MeSH
- reoperace metody MeSH
- selhání protézy škodlivé účinky MeSH
- tryptasy imunologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- dendritické buňky chemie ultrastruktura MeSH
- Langerhansovy buňky chemie ultrastruktura MeSH
- Langerhansovy ostrůvky MeSH
- výzkum MeSH
- Publikační typ
- kongresy MeSH
- MeSH
- B-lymfocyty cytologie metabolismus ultrastruktura MeSH
- dendritické buňky imunologie metabolismus ultrastruktura MeSH
- exprese genu MeSH
- krysa rodu rattus MeSH
- makrofágy cytologie metabolismus ultrastruktura MeSH
- MHC antigeny II. třídy genetika metabolismus MeSH
- omentum MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- ženské pohlaví MeSH
- zvířata MeSH
