title: Cytokine induction of sol-gel-derived TiO2and SiO2coatings on metallic substrates after implantation to rat femur.
abstract: Material surface is a key determinant of host response on implanted biomaterial. Therefore, modification of the implant surface may optimize implant-tissue reactions. Inflammatory reaction is inevitable after biomaterial implantation, but prolonged inflammation may lead to adverse reactions and subsequent implant failure. Proinflammatory activities of cytokines like interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha (TNF-α) are attractive indicators of these processes and ultimately characterize biocompatibility. The objective of the study was to evaluate local cytokine production after implantation of stainless steel 316L (SS) and titanium alloy (Ti6Al4V) biomaterials coated with titanium dioxide (TiO2) and silica (SiO2) coatings prepared by sol-gel method. Biomaterials were implanted into rat femur and after 12 weeks, bones were harvested. Bone-implant tissue interface was evaluated; immunohistochemical staining was performed to identify IL-6, TNF-α, and Caspase-1. Histomorphometry (AxioVision Rel. 4.6.3 software) of tissue samples was performed in order to quantify the cytokine levels. Both the oxide coatings on SS and Ti6Al4V significantly reduced cytokine production. However, the lowest cytokine levels were observed in TiO2groups. Cytokine content in uncoated groups was lower in Ti6Al4V than in SS, although coating of either metal reduced cytokine production to similar levels. Sol-gel TiO2or SiO2coatings reduced significantly the production of proinflammatory cytokines by local tissues, irrespective of the material used as a substrate, that is, either Ti6Al4V or SS. This suggests lower inflammatory response, which directly points out improvement of materials' biocompatibility.
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Wroclaw University Hospital.
authors.forename: Wiktor
authors.initials: W
authors.lastname: Urbanski
authors.affiliation: Electron Microscope Laboratory, Wroclaw University of Environmental and Life Sciences.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Marycz
authors.affiliation: Institute of Materials Science and Applied Mechanics.
authors.forename: Justyna
authors.initials: J
authors.lastname: Krzak
authors.affiliation: Division of Biomedical Engineering and Experimental Mechanics, Wroclaw University of Technology, Wroclaw, Poland.
authors.forename: Celina
authors.initials: C
authors.lastname: Pezowicz
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Wroclaw University Hospital.
authors.forename: Szymon Feliks
authors.initials: SF
authors.lastname: Dragan
mesh_terms: D000818:Animals; D020099:Coated Materials, Biocompatible / Q000494:pharmacology*; D016207:Cytokines / Q000378:metabolism*; D005269:Femur / Q000187:drug effects*; D007150:Immunohistochemistry; D020007:Implants, Experimental; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D008670:Metals / Q000494:pharmacology*; D044367:Phase Transition; D017208:Rats, Wistar; D012822:Silicon Dioxide / Q000494:pharmacology*; D013499:Surface Properties; D014025:Titanium / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D020099:Coated Materials, Biocompatible; D016207:Cytokines; D015850:Interleukin-6; D008670:Metals; D014409:Tumor Necrosis Factor-alpha; C009495:titanium dioxide; D012822:Silicon Dioxide; D014025:Titanium
keywords: biomaterial; bone implant; inflammation; sol–gel coatings; surface modification