TY - JOUR
T1 - Titanium IV ions induced human osteoclast differentiation and enhanced bone resorption in vitro
AU - Cadosch, D.
AU - Chan, E.
AU - Gautschi, O.
AU - Meagher, Jamie
AU - Zellweger, R.
AU - Filgueira, Luis
PY - 2009
Y1 - 2009
N2 - There is increasing evidence that titanium (Ti) ions are released from orthopedic implants, with concentrations in the range of 1 μM in tissue and blood, and may play a role in aseptic loosening of orthopedic implants. This study investigated whether Ti(IV) ions induce differentiation of monocytic osteoclast precursors into osteo-resorptive multinucleated cells and influence the activation and function of in vitro generated osteoclasts. Human monocytes and in vitro generated osteoclasts were exposed to 1 μM Ti(IV) ions for 10 days. Thereafter, osteoclast differentiation, activation, and function were evaluated. Transcription of specific osteoclastic genes was measured using quantitative reverse transcription polymerase chain reactions, which showed increased expression of tartrate-resistant acid phosphatase (TRAP) in ∼20% of Ti(IV)-treated monocytes. Detection and quantification of intracellular TRAP activity using ELF97 as a fluorescent substrate revealed a significant increase of TRAP-positive cells in Ti(IV)-treated monocytes. Additionally, as demonstrated on dentin slide cultures, Ti(IV)-treated monocytes became functional bone resorbing cells, significantly increasing their osteo-resorptive activity to similar levels as osteoclasts in vitro. These results suggest that Ti(IV) ions released by biocorrosion from orthopedic implants induce differentiation of monocytes toward mature, functional osteoclasts, which may well contribute the pathomechanism of aseptic loosening. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
AB - There is increasing evidence that titanium (Ti) ions are released from orthopedic implants, with concentrations in the range of 1 μM in tissue and blood, and may play a role in aseptic loosening of orthopedic implants. This study investigated whether Ti(IV) ions induce differentiation of monocytic osteoclast precursors into osteo-resorptive multinucleated cells and influence the activation and function of in vitro generated osteoclasts. Human monocytes and in vitro generated osteoclasts were exposed to 1 μM Ti(IV) ions for 10 days. Thereafter, osteoclast differentiation, activation, and function were evaluated. Transcription of specific osteoclastic genes was measured using quantitative reverse transcription polymerase chain reactions, which showed increased expression of tartrate-resistant acid phosphatase (TRAP) in ∼20% of Ti(IV)-treated monocytes. Detection and quantification of intracellular TRAP activity using ELF97 as a fluorescent substrate revealed a significant increase of TRAP-positive cells in Ti(IV)-treated monocytes. Additionally, as demonstrated on dentin slide cultures, Ti(IV)-treated monocytes became functional bone resorbing cells, significantly increasing their osteo-resorptive activity to similar levels as osteoclasts in vitro. These results suggest that Ti(IV) ions released by biocorrosion from orthopedic implants induce differentiation of monocytes toward mature, functional osteoclasts, which may well contribute the pathomechanism of aseptic loosening. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
U2 - 10.1002/jbm.a.32183
DO - 10.1002/jbm.a.32183
M3 - Article
C2 - 18683234
VL - 91A
SP - 29
EP - 36
JO - Journal of Biomedical Materials Research
JF - Journal of Biomedical Materials Research
SN - 1549-3296
ER -