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- Yang, Xianyan, et al.
(författare)
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Intra-bone marrow injection of trace elements co-doped calcium phosphate microparticles for the treatment of osteoporotic rat
- 2017
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Ingår i: Journal of Biomedical Materials Research. Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 105:5, s. 1422-1432
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Tidskriftsartikel (refereegranskat)abstract
- Osteoporotic femur fractures are the most common fragility fracture and account for approximately one million injuries per year. Local intervention by intra-marrow injection is potentially a good choice for preventing osteoporotic bone loss when the osteoporotic femoral fracture was treated. Previously, it was shown that trace element co-doped calcium phosphate (teCaP) implants could stimulate osteoporotic bone marrow mesenchymal stem cell activity in vitro and bone regeneration in femoral bone defects in osteoporotic animal models. They hypothesized that local intra-marrow injection of teCaP particles could improve bone function because the teCaP can sustain release of biologically essential inorganic minerals and improve bone remodeling in osteoporosis. The teCaP and CaP particles were synthesized in simulated body fluid with and without adding silicon, zinc and strontium ions. Female rats (8 months) were ovariectomized (OVX) or sham-operated, and then intervened in the femoral marrow space at 12 months old. Groups include: (1) saline water; (2) CaP particles; and (3) teCaP particles. After 2-3 months of intervention, the sham groups showed higher bone mineral density (MBD) in the femur, and teCaP group increased the BMD in the OVX groups. The compressive strength of the OVX-teCaP group was significantly higher than that in the OVX-CaP group. Significant differences between OVX-teCaP and OVX-CaP groups were found for bone mineral microarchitecture, bone mineral density, and trace mineral content, but not for feces composition. These results confirm the teCaP particles could suppress osteoporotic bone loss by local intramarrow injection. Therefore, this biomaterial could be used as a next-generation combination treatment for osteoporotic trauma and osteoporosis itself.
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| 2. |
- Zhang, Guiling, et al.
(författare)
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Understanding the influence of alendronate on the morphology and phase transformation of apatitic precursor nanocrystals
- 2012
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Ingår i: Journal of Inorganic Biochemistry. - : Elsevier BV. - 0162-0134 .- 1873-3344. ; 113, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Bisphosphonates (BPs) are a class of synthetic pyrophosphate analogs that can prevent the loss of bone mass, given orally to treat postmenopuasal osteoporosis. It is not clear yet if the benefits of BPs include the possibility of affecting bone apatitic precursors transition for bone consolidation except for encouraging osteoclasts to undergo apoptosis. Furthermore, the complexity of the in vivo system makes it difficult to isolate and study such extracellular topographical cues that trigger bone turnover response. Herein, we proposed a wet-chemical approach employing alendronate sodium (AS) as a guide of hydroxyapatite (HA) precursor growth and conversion which was initiated from the nucleantion of octacalcium phosphate (OCP) in a cell membrane-mimicking surfactant micelle aqueous system. The nanocrystal clusters of dicalcium phosphate dihydrate (DCPD) and OCP nanocryatals were readily precipitated within a relatively narrow AS concentration range (2-8 mu M). However, such low concentrations of AS seemed to stabilize the more acidic phases, and to delay the transformation into HA, to an extent which increased on increasing AS concentration. In contrast, at a slight higher concentrations (16-32 mu M), AS promoted HA precipitation after ageing for 1 h. It was found that the effect of AS on the phase selectivity of apatitic precursors was concentration-dependent within a prolonged ageing time stage (0.5-168 h). The AS-assisted reactions in vitro offer an expedient way to understand the underlying implementarity between bone and BPs for bone consolidation, and to improve our understanding of benefit of BP dosages on bone turnover and trauma healing.
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