Anatase and Rutile TiO2 Nanoparticles Lead Effective Bone Damage in Young Rat Model via the IGF-1 Signaling Pathway

Abstract

To evaluate the effects of anatase and rutile TiO 2 nanoparticles (NPs) on the growth and development of bones in young rats and explore their possible mechanisms. Methods: Three-week-old male rats were orally administered anatase TiO 2 NPs and rutile TiO 2 NPs for 28 days. The indicators of rat growth and development, liver function, bone metabolism, and insulin-like growth factor-1 (IGF-1) levels were evaluated. Micro-computed tomography (micro-CT) and immunohistochemistry were used to evaluate the tibia. Results: No significant differences were observed among growth and development indicators in young rats. Significant differences were found in IGF-1 levels, phosphorus levels, and liver function. Micro-CT revealed osteoporosis in the bones. The micro-CT data supported the same result. Bone immunohistochemistry results showed that the expression of osteoprotegerin (OPG) was decreased and the expression of receptor activator of nuclear factor-κB ligand (RANKL) and cathepsin K (CTSK) was increased. Conclusion:This study demonstrated that TiO 2 NPs can damage bones via the IGF-1/OPG/ RANKL/CTSK pathway in young rats. Furthermore, rutile TiO 2 NPs damaged the bones more seriously than anatase TiO 2 NPs.

Polystyrene microplastic‐induced endoplasmic reticulum stress contributes to growth plate endochondral ossification disorder in young rat

“…Our images showed trabecular disruption and sparse osteoporotic‐like structural damage in the group exposed to MPs (Figure 3A–D). Similar results were observed in previous studies, which also confirmed the exposure of environmental particulate matter contributed to osteoporosis manifestation 13,43 . Our micro‐CT data also demonstrated structural damage in bone.…”

“…Similar results were observed in previous studies, which also confirmed the exposure of environmental particulate matter contributed to osteoporosis manifestation. 13,43 Our micro-CT data also demonstrated structural damage in bone. BS/TV and BV/TV were significantly decreased in the MPs exposure groups (Figure 4A,B), reflecting a reduction in cancellous bone mass.…”

Investigating the influence of titanium particle size and concentration on osteogenic response of human osteoblasts – in vitro study

“…However, the effect of these wear particles on the osteoblasts based on their concentration, size, and morphology is not well demonstrated. Studies have shown that TiO 2 nanoparticles have varying effects on osteoblasts and osteoblast-like cells [ 10 , 11 ]. Osteogenic inhibition and bone loss induced by the wear of titanium alloy are crucial in the instigation of peri-prosthetic osteolysis [ 12 ].…”

“…The OPG/RANKL ratio is an important factor in determining the bone mass in normal and osteoporotic cases [ 14 ]. Previous studies have demonstrated that TiO 2 particles can disrupt the OPG/RANKL homeostasis and inhibit the osteoblasts' activity [ 11 ]. M-CSF is another secretory cytokine that plays a crucial role in maintaining the osteoblast/osteoclast equilibrium [ 17 ].…”