Biological Response of Osteoblasts and Osteoprogenitors to Orthopaedic Wear Debris

Cobalt, titanium and PMMA bone cement debris influence on mouse osteoblast cell elasticity, spring constant and calcium production activity

“…Generally, the first stages of an adverse effect is the phagocytosis of the particles by cells; this has been visually demonstrated using polystyrene-based fluorescent particles, such as fluoresbrite, that were internalised within 24 hours of in vitro exposure, with cells being saturated with around 40–60 particles per cell. 37 These results are in agreement with our findings that reveal changes in the cell properties after 24 hours of exposure to nanoparticles.…”

“…Some of the above studies 11 , 24 , 35 , 36 , 37 , 40 , 41 , 43 , 44 , 48 have demonstrated that orthopaedic wear debris affects the viability of cells, including their proliferation, differentiation, and function. Yet, many of these studies do not coincide, featuring many discrepancies such as the choice of cell, cell population, culturing conditions, not to mention the wear debris compositions variances such as the size, composition, dose and aggregation.…”

Bioeffects of micron‐size magnesium particles on inflammatory cells and bone turnover in vivo and in vitro

“…22,29,30 In the in vitro system, the effects of TiMPs on the expression of inflammatory cytokines was similar to that reported previously, 31,32 but MgMPs caused necrosis of RAW264.7 cells, leading to increased cytokine expression after 48 h of coculture. This effect was stronger at higher P:C ratios.…”

“…33 Typically, particles containing nonabsorbable materials elicit inflammatory, osteolytic, and granulomatous cascade reactions and inhibit osteogenic process. 34 As previously reported, 22,30 TiMPs significantly enhanced osteolytic marker expression, but we find here that MgMPs do not. However, MgMPs significantly increased OCN expression, but had no effect on ALP expression.…”

Do Genetic Susceptibility, Toll-like Receptors, and Pathogen-associated Molecular Patterns Modulate the Effects of Wear?

“…Consistent with that possibility, antibodies that neutralize sclerostin, an inhibitor of wnt signaling, block the negative effect of polyethylene particles on implant fixation in rats by increasing bone formation and decreasing bone resorption [60]. Also consistent with that possibility, the number of osteoblasts is reduced on bone surfaces surrounding loose implants [49]; patients with high rates of bone formation have lower rates of aseptic loosening [55]; wear particles can reduce osteogenesis in vitro and in animal models [17,108]; and osteoblasts rapidly repair osteolysis induced by wear particles in young mice [48]. Another possibility is that altered wnt signaling results in skeletal anatomy that predisposes the patient to loosening.…”