Cytokine release by osteoblast-like cells cultured on implant discs of varying alloy compositions.
OBJECTIVE
The aims of this study were (i). to assess the morphological features of osteo-blast-like, osteosarcoma cells (cell line SaOS-2) cultured on implant surfaces of varying alloys and (ii). to evaluate the biological activity of these cells, following their adhesion onto these surfaces.


METHODS
SaOS-2 cells (6 x 104) were grown on titanium discs (diameter 30 mm), each with a surface of differing composition and roughness (commercially pure titanium, titanium-aluminium-vanadium alloy, oxide-blasted titanium and Astra-Tech special treatment titanium; the alloys are directly comparable with those used to construct implants). The cells were grown for time periods of 1, 3, 5 and 7 days, the media were collected and the cells were fixed with 2.5% glutaraldehyde. The media were then assayed (using enzyme-linked immunosorbant assay) for the levels of interleukin (IL)-1, interleukin-6, interleukin-18 and osteoprotegerin (OPG) produced by the cells. The discs, with the cells fixed on them, were viewed under scanning electron microscopy (SEM, x 2.0 k) to evaluate cell morphology.


RESULTS
Following attachment, the cells changed their morphology and released local factors known to activate osteoclasts. Commercially pure titanium stimulated the cells the most and titanium-aluminium-vanadium alloy the least. All implant materials stimulated production of IL-1, IL-6, IL-18 above that produced by cells grown on Petri dishes (polystyrene). The titanium-aluminium-vanadium alloy allowed cell attachment but levels of IL-1 in this medium were significantly lower (31.5 +/- 5.2 pg/ml on same day) than cultures with pure titanium (201.8 +/- 11.5 pg/ml at day 5). The same pattern was observed with the IL-6, IL-18, and OPG with polystyrene appearing to stimulate most production of OPG. Titanium-aluminium-vanadium produced the least biological response.
Spyrou
Pericles
P
Department of Orthodontics, GKT Schools of Medicine and Dentistry, London, UK.
Papaioannou
Stelios
S
Hampson
Geeta
G
Brady
Ken
K
Palmer
Richard M
RM
McDonald
Fraser
F
D000497:Alloys; D001672:Biocompatible Materials / Q000737:chemistry; D002448:Cell Adhesion; D002452:Cell Count; D002460:Cell Line; D048429:Cell Size; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D017077:Culture Media, Conditioned; D003722:Dental Alloys / Q000737:chemistry*; D015921:Dental Implants; D004797:Enzyme-Linked Immunosorbent Assay; D006023:Glycoproteins / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism; D020382:Interleukin-18 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D007378:Interleukins / Q000032:analysis / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000378:metabolism*; D053244:Osteoprotegerin; D012516:Osteosarcoma / Q000378:metabolism*; D010087:Oxides / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry; D018160:Receptors, Cytoplasmic and Nuclear / Q000032:analysis; D018124:Receptors, Tumor Necrosis Factor / Q000032:analysis*; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*
D000497:Alloys; D001672:Biocompatible Materials; D020099:Coated Materials, Biocompatible; D017077:Culture Media, Conditioned; D003722:Dental Alloys; D015921:Dental Implants; D006023:Glycoproteins; D007375:Interleukin-1; D020382:Interleukin-18; D015850:Interleukin-6; D007378:Interleukins; D053244:Osteoprotegerin; D010087:Oxides; D011137:Polystyrenes; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; C506030:TNFRSF11B protein, human; C031462:titanium alloy (TiAl6V4); D014025:Titanium