Astaxanthin prevents bone loss in osteoporotic rats with palmitic acid through suppressing oxidative stress.

OBJECTIVES: The study aimed to assess the role of Astaxanthin (ATX) in palmitic acid(PA) -induced bone loss in Ovariectomized(OVX) rats. METHODS: In the OVX rat model, we observed that PA affects bone metabolism and accelerates bone loss. Additionally, treatment with ATX was able to suppress the deleterious effects of PA and a simultaneous decrease in serum MDA levels and an increase in SOD was observed. RESULTS: In addition, rats treated with ATX were observed to have significantly increased bone mass and elevated activity of SIRT1 and SOD2 in bone tissue. When MC3T3-E1 and RAW264.7 cells induced osteoblast and osteoclast differentiation, the ATX intervention was able to significantly restore the restriction of osteogenic differentiation and the up-regulation of osteoclast differentiation with PA therapy. Furthermore, we confirm that PA damage to cells is caused by increased oxidative stress, and that ATX can target and modulate the activity of SIRT1 to regulate the levels of oxidative stress in cells. CONCLUSION: Summarizing, ATX may inhibit PA-induced bone loss through its antioxidant properties via the SIRT1 signaling pathway.

Favorable osteogenic activity of vericiguat doped in ß-tricalcium phosphate: In vitro and in vivo studies.

Recently, more and more studies have shown that guanylate cyclase, an enzyme that synthesizes cyclic guanosine monophosphate (cGMP), plays an important role in bone metabolism. Vericiguat (VIT), a novel oral soluble guanylate cyclase stimulator, directly generates cyclic guanosine monophosphate and reduce the death incidence from cardio-vascular causes or hospitalization. Recent studies have shown beneficial effects of VIT in animal models of osteoporosis, but very little is currently known about the effects of VIT on bone defects in the osteoporotic states. Therefore, in this study, ß-tricalcium phosphate (ß-TCP) was used as a carrier to explore the effect of local VIT administration on the repair of femoral metaphyseal bone defects in ovariectomized (OVX) rats. When MC3T3-E1 was cultured in the presence of H2H2, VIT, similar to Melatonin (MT), therapy could increase the matrix mineralization and ALP, SOD2, SIRT1, and OPG expression, reduce ROS and Mito SOX production, RANKL expression, Promote the recovery of mitochondrial membrane potential. In the OVX rat model, VIT increases the osteogenic effect of ß-TCP and better results were obtained at a dose of 5 mg. Local use of VIT can inhibit increased OC, BMP2 and RUNX2 expressions in bone tissue, while decreased SOST and TRAP expressions by RT-PCR and immunohistochemistry. Thereby, VIT stimulates bone regeneration and is a promising candidate for promoting bone repair in osteoporosis.

Cyclosporine a inhibits bone regeneration and induces bone loss in a rat model.

Cyclosporine A (CSA) is an immunosuppressant that has been extensively studied for its side effects on inhibiting osseointegration of titanium implants. However, the impact of CSA on bone healing in postmenopausal osteoporosis remains unknown. Therefore, this study aimed to investigate the effect of CSA on bone repair in an ovariectomized (OVX) rat model through both in vitro and in vivo experiments. We examined the interventions of CSA on osteoblast progenitor cells MC3T3-E1 and assessed their effects on biological function using RT-qPCR, CCK-8 assay, alizarin red staining, and alkaline phosphatase staining. Furthermore, we evaluated the effects of CSA on bone regeneration and bone mass in both OVX rat models and femoral diaphysis bone defect models. The results from the CCK-8 experiment indicated a positive influence of experimental doses of CSA on osteogenic differentiation of MC3T3-E1 cells. ALP expression levels and calcified nodules were also evaluated, suggesting that CSA intervention promoted osteogenic differentiation in MC3T3-E1 cells. Additionally, specific gene expressions including OPN, Runx-2, OC, and Col1a1 were up-regulated after CSA intervention. Biomechanical parameters aligned with histological analysis as well as micro-CT scans confirmed worse bone microstructure and strength following CSA intervention. Our findings preliminarily suggest that whether it is normal or osteoporotic bones, CSA has adverse effects on bone health which are associated with elevated-bone turnover.

Co-modified 3D printed ß-tricalcium phosphate with magnesium and selenium promotes bone defect regeneration in ovariectomized rat.

Magnesium (Mg) and Selenium (Se) are essential elements for bone health and have been studied extensively for its powerful osteogenesis and promoting bone regeneration. The purpose was to observe whether Co-modified 3D-printed ß-tricalcium phosphate with Mg and Se could promote bone defect regeneration in an ovariectomized(OVX) rat model. The MC3T3-E1 cells were co-cultured with the leachate of ß-TCP, Mg-TCP, and Mg/Se-TCP and induced to osteogenesis, and the cell viability, ROS, and osteogenic activity were observed by Cell Count Kit-8(CCK-8), fluorescent probe 2', 7'-dichlorofluorescin diacetate, Alkaline phosphatase (ALP) staining, Alizarin Red(RES) staining, western blotting(WB), and immunofluorescence. Then the ß-TCP, Mg-TCP, and Mg/Se-TCP were implanted into the femoral epiphysis bone defect model of OVX rats for 12 weeks. Micro-CT and histology analysis were used to observe the therapeutic effect. In vitro results show that the cell mineralization and osteogenic activity of the Mg/Se-TCP group is significantly higher than the ß-TCP group and Mg-TCP group. Protein expressions such as FOxO1, SIRT1, SOD2, Runx-2, Cola1a, and OC of the Mg/Se-TCP group are significantly higher than the Con group and the ß-TCP group. The results of intracellular ROS and SIRT1 and SOD2 immunofluorescence showed that Mg/Se-TCP can restore the oxidative stress balance of osteoblasts. Micro-CT and histology analysis showed that treatment with Mg/Se-TCP showed the largest amount of bone tissue in the defect area (p < 0.05), and exhibited lower values of residual biological material (p < 0.05), compared to that of the ß-TCP group and Mg-TCP group. Our research results confirm that Mg/Se-TCP can improve the activity and function of osteoblasts and enhance bone regeneration mediated by reducing intracellular ROS in OVX rat models. The release of Mg and Se during the degradation of Mg/Se-TCP can improve the local bone repair ability. At the same time, it can also inhibit cell ROS, and ultimately greatly promote local bone repair.

Systemic administration with melatonin in the daytime has a better effect on promoting osseointegration of titanium rods in ovariectomized rats.

AIMS: This study examined whether systemic administration of melatonin would have different effects on osseointegration in ovariectomized (OVX) rats, depending on whether this was administered during the day or night. METHODS: In this study, a titanium rod was implanted in the medullary cavity of one femoral metaphysis in OVX rats, and then the rats were randomly divided into four groups: Sham group (Sham, n = 10), OVX rat group (OVX, n = 10), melatonin day treatment group (OVX + MD, n = 10), and melatonin night treatment group (OVX + MN, n = 10). The OVX + MD and OVX + MN rats were treated with 30 mg/kg/day melatonin at 9 am and 9 pm, respectively, for 12 weeks. At the end of the research, the rats were killed to obtain bilateral femora and blood samples for evaluation. RESULTS: Micro-CT and histological evaluation showed that the bone microscopic parameters of femoral metaphysis trabecular bone and bone tissue around the titanium rod in the OVX + MD group demonstrated higher bone mineral density, bone volume fraction, trabecular number, connective density, trabecular thickness, and lower trabecular speculation (p = 0.004) than the OVX + MN group. Moreover, the biomechanical parameters of the OVX + MD group showed higher pull-out test and three-point bending test values, including fixation strength, interface stiffness, energy to failure, energy at break, ultimate load, and elastic modulus (p = 0.012) than the OVX + MN group. In addition, the bone metabolism index and oxidative stress indicators of the OVX + MD group show lower values of Type I collagen cross-linked C-telopeptide, procollagen type 1 N propeptide, and malondialdehyde (p = 0.013), and higher values of TAC and SOD (p = 0.002) compared with the OVX + MN group. CONCLUSION: The results of our study suggest that systemic administration with melatonin at 9 am may improve the initial osseointegration of titanium rods under osteoporotic conditions more effectively than administration at 9 pm.Cite this article: Bone Joint Res 2022;11(11):751-762.

Silibinin-modified Hydroxyapatite coating promotes the osseointegration of titanium rods by activation SIRT1/SOD2 signaling pathway in diabetic rats.

The purpose of this study is to investigate the role of Silibinin (SIL)-modified Hydroxyapatite coating on osseointegration in diabetes in vivo and in vitro and explore the mechanism of osteogenic differentiation of MC3T3-E1. RT-qPCR, Immunofluorescence, and Western blot were used to measure the expression level of oxidative Stress Indicators and osteogenic markers proteins. Moreover, CCK-8 assay was conducted to detect cell viability in hyperglycemia. Alizarin red staining and alkaline phosphatase staining were used to examine osteogenic function and calcium deposits. The diabetic rat model receive titanium rod implantation was set up successfully and Von-Gieson staining was used to examine femoral bone tissue around titanium rod. Our results showed that intracellular oxidative stress in hyperglycemia was overexpressed, while FoxO1, SIRT1, GPX1, and SOD2 were downregulated. SIL suppressed oxidative stress to promote osteogenic differentiation. Additionally, it was confirmed that SIL promoted osteogenic differentiation of MC3T3-E1 and obviously restored the osseointegration ability of diabetic rats. Further study indicated that SIL exerted its beneficial function through activation SIRT1/SOD2 signaling pathway to restore osteoblast function, and improved the osseointegration and stability of titanium rods in vivo. Our research suggested that the SIL-modulated oxidative Stress inhibition is responsible for the activation of the process of osteogenic differentiation through activation SIRT1/SOD2 signaling pathway in hyperglycemia, providing a novel insight into improving prosthetic osseointegration in diabetic patients. Hyperglycemia impaired the activity and function of MC3T3-E1 and inhibits bone formation by up-regulating intracellular ROS levels through inhibition of SIRT1/SOD2 signaling pathway. Local administrator SIL can improve the activity and function of osteoblasts and enhance osseointegration by reducing intracellular ROS through activation of SIRT1/SOD2 signaling pathway in DM rat models.

Silymarin prevents iron overload induced bone loss by inhibiting oxidative stress in an ovariectomized animal model.

Silibinin (SIL) has been used extensively for its hepatoprotective properties and antioxidant properties, including bone health. Iron overload can inhibit osteogenic proliferation and differentiation and promote bone loss. However, whether SIL can reverse the harmful effects of iron overload inovariectomized (OVX) rats and the mechanism is not clear. Therefore, this study intends to investigate the effect of SIL on bone mass and bone metabolism in iron overload rats and also explore the role of SIL on osteogenic differentiation of MC3T3-E1.RT-qPCR was used to measure the transcribe of target genes. Furthermore, alizarin red staining, alkaline phosphatase staining, immunofluorescence and CCK-8 assay were conducted to detect cell viability and target protein expression, osteogenic function. The OVX rat model with iron overload was set up to investigate bone reconstruction.Our results demonstrated that SIL promotes the proliferation and differentiation of osteoblasts, increases the ALP secretion and mineralization ability of osteoblasts, and enhances the transcribe and expression of target genes including OC, Runx-2, SOD2 and SIRT1 in an iron overload environment. In addition, it was confirmed that systemic SIL administration inhibits bone loss in OVX rats with iron overload and changes bone metabolism and oxidative stress status. Further study has shown that iron overload exerts its harmful function by accelerating bone turnover-mediated changes in higher bone metabolism to worsen osteoporosis. SIL can inhibit the unfriendly effects of iron overload, and by modifying bone metabolism and oxidative stress levels, the results contribute to clinical prevention and treatment of the progression of postmenopausal osteoporosis.

Probucol promotes osteoblasts differentiation and prevents osteoporosis development through reducing oxidative stress.

Probucol (PBC) is a potent cholesterol-lowering drug and has been studied extensively for its powerful antioxidative stress. The purpose of this study is to investigate the role of PBC in ovariectomized rat model and to explore the mechanism of osteogenic differentiation of MC3TE-E1 Cells. RT-qPCR and Immunofluorescence were used to measure the expression level of SOD2, SIRT1, intracellular oxidative stress levels and osteogenic markers proteins. Moreover, CCK-8 assay was conducted to detect cell viability. Alizarin red staining and alkaline phosphatase staining were applied to examine osteogenic function and calcium deposits. The ovariectomized rat model was set up successfully and HE staining were employed to examine femoral trabeculae tissue. Our results showed that PBC suppressed MC3TE-E1 resist oxidative stress to promote osteogenic differentiation. Additionally, it was confirmed that PBC promoted osteogenic differentiation of MC3TE-E1 through inhibiting oxidative stress. Further study indicated that PBC exerted its beneficial function by suppressing oxidative stress-mediated alter bone metabolism to alleviate osteoporosis in vivo. Our research suggested that the PBC-modulated oxidative stress inhibition is responsible for activation of the process of osteogenic differentiation, providing a novel insight into the treatment of osteoporosis.

Hydrogel contained valproic acid accelerates bone-defect repair via activating Notch signaling pathway in ovariectomized rats.

The purpose was to observe whether valproic acid (VPA) has a positive effect on bone-defect repair via activating the Notch signaling pathway in an OVX rat model. The MC3T3-E1 cells were cocultured with VPA and induced to osteogenesis, and the osteogenic activity was observed by alkaline phosphatase (ALP) staining, Alizarin Red (RES) staining and Western blotting (WB). Then the hydrogel-containing VPA was implanted into the femoral epiphysis bone-defect model of ovariectomized (OVX) rats for 12 weeks. Micro-CT, biomechanical testing, histology, immunofluorescence, RT-qPCR, and WB analysis were used to observe the therapeutic effect and explore the possible mechanism. ALP and ARS staining and WB results show that the cell mineralization, osteogenic activity, and protein expression of ALP, OPN, RUNX-2, OC, Notch 1, HES1, HEY1, and JAG1 of VPA group is significantly higher than the control group. Micro-CT, biomechanical testing, histology, immunofluorescence, and RT-qPCR evaluation show that group VPA presented the stronger effect on bone strength, bone regeneration, bone mineralization, higher expression of VEGFA, BMP-2, ALP, OPN, RUNX-2, OC, Notch 1, HES1, HEY1, and JAG1 of VPA when compared with OVX group. Our current study demonstrated that local treatment with VPA could stimulate repair of femoral condyle defects, and these effects may be achieved by activating Notch signaling pathway and acceleration of blood vessel and bone formation.

Local administration with tauroursodeoxycholic acid could improve osseointegration of hydroxyapatite-coated titanium implants in ovariectomized rats.

Despite advances in the pathogenesis of Tauroursodeoxycholic acid (TUDCA) on bone, the understanding of the effects and mechanisms of bone osseointegration in TUDCA-associated Hydroxyapatite (HA)-coated titanium implants remains poor. Therefore, the present work was aimed to evaluate the effect of local administration with TUDCA on HA-coated titanium implants osseointegration in ovariectomized(OVX) rats and further investigation of the possible mechanism. Twelve weeks after bilateral ovariectomy, all animals were randomly divided into three groups: sham operation(Sham) group, OVX group and TUDCA group, and all the rats from Sham group and OVX group received HA implants and animals belonging to group TUDCA received TUDCA-HA implants until death at 12 weeks. The bilateral femurs of rats were harvested for evaluation. TUDCA increased new bone formation around the surface of titanium rods and push-out force other than group OVX. Histology, Micro-CT and biochemical analysis results showed systemic TUDCA showed positive effects than OVX group on bone formation in osteopenic rats, with beneficial effect on via activation OPG/RANKL pathway and BMP-2/Smad1 pathway and microarchitecture as well as by reducing protein expression of TNF-α and IFN-γ. The present study suggests that local use of TUDCA may bring benefits to the osseointegration of HA-coated titanium implants in patients with osteoporosis, and this effect may be related to the inhibition of inflammatory reaction and promotion of osteogenesis.

Selenium-modified calcium phosphate cement can accelerate bone regeneration of osteoporotic bone defect.

OBJECTIVE: The purpose is to observe whether local administration with selenium (Se) can enhance the efficacy of calcium phosphate cement (CPC) in the treatment of osteoporotic bone defects. METHODS: Thirty ovariectomized (OVX) rats with two defects were generated and randomly allocated into the following graft study groups: (1) OVX group (n = 10), (2) CPC group (n = 10); and (3) Se-CPC group (n = 10). Then, these selenium-modified calcium phosphate cement (Se-CPC) scaffolds were implanted into the femoral epiphysis bone defect model of OVX rats for 12 weeks. Micro-CT, history, western blot and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis were used to observe the therapeutic effect and to explore the possible mechanism. RESULT: Micro-CT and histological analysis evaluation showed that the Se-CPC group presented the strongest effect on bone regeneration and bone mineralization when compared with the CPC group and the OVX group. Protein expressions showed that the oxidative stress protein expressions, such as SOD2 and GPX1 of the Se-CPC group, are significantly higher than those of the OVX group and the CPC group, while Se-CPC remarkably reduced the expression of CAT. RT-qPCR analysis showed that the Se-CPC group displayed more OPG than the OVX and CPC groups (p < 0.05), while Se-CPC exhibited less RANKL than the OVX and CPC groups (p < 0.05). CONCLUSION: Our current study demonstrated that Se-CPC is a scheme for rapid repair of femoral condylar defects, and these effects may be achieved by inhibiting local oxidative stress and through OPG/RANKL signaling pathway.

Simvastatin reverses the harmful effects of high fat diet on titanium rod osseointegration in ovariectomized rats.

INTRODUCTION: The objectives of the present study were to determine whether simvastatin (SIM) could reverse the harmful effects on titanium rod osseointegration in ovariectomized rats fed high-fat diet (HFD). MATERIALS AND METHODS: Ovariectomized female Sprague-Dawley rats were randomly allocated to three groups and received SIM treatment plus HFD for 12 weeks. We then evaluated the microstructure parameters, histological parameters, biomechanical parameters, bone turnover, and blood lipid level. RESULTS: After 12 weeks of treatment, SIM can significantly improve bone formation around the titanium rod and osseointegration including higher values of maximum push-out force, bone area ratio (BAR), bone-to-implant contact (BIC), bone mineral density (BMD), bone volume (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), mean connective density (Conn.D) when compared with the HFD group. In addition, system administration of SIM showed positive effects on collagen type 1 cross-linked C-telopeptide (CTX-1), procollagen I N-terminal propeptide (PINP), total cholesterol (TC), triglycerides (TGL), low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol. Compared with the HFD group, lower values of CTX-1, P1NP, TC, TGL and LDL were observed in the SIM+HFD group (P < 0.05). CONCLUSION: Our findings revealed that HFD may have an adverse effect on osseointegration in osteoporotic conditions, and the harmful effect of HFD on osseointegration could be reversed by SIM.

Intermittent administration sodium valproate has a protective effect on bone health in ovariectomized rats.

The present work was aimed to evaluate the effect of different administration modes of sodium valproate (VPA) on bone strength, bone mass and bone mineral density in ovariectomized (OVX) rats and further investigation of the possible mechanism. 60 female SD rats were randomly divided into 4 groups: Sham group (Sham, n = 15), OVX group (OVX, n = 15), OVX rats received intermittent VPA treatment group (IVPA, n = 15) and OVX rats received daily VPA treatment group (EVPA, n = 15). After 12 weeks of treatment, the rats were sacrificed, and serum and femur samples were harvested. DEXA, Micro-CT, history, biomechanical testing, biochemical index and western blot analysis were used to observe the therapeutic effect and explore the possible mechanism. Micro-CT and DEXA analysis of bones revealed better BMD and higher BV/TV, Tb. Th, Tb. N, Conn. D and lower Tb. Sp at femoral metaphysis evaluated in IVPA when compared with OVX and EVPA group (P < 0.05). Histological, fluorescent analysis and biological strength revealed more trabecular bone and higher relative mineral apposition rate, maximal load, elastic modulus and energy at break with evaluated in IVPA when compared with OVX and EVPA group (P < 0.05). The levels of P1NP, estrogen, CTX, TRAP-5b and RANKL of the IVPA group showed a significant increase when compared with the OVX and EVPA group (P < 0.05). We confirm adverse effects on protein expressions including Notch1, Jagged1, HEY1, Wnt 1, ß-catenin and RUNX2 following daily VPA treatment in OVX female rats. Our current study demonstrated that intermittent administration of sodium valproate has a protective effect on bone health in OVX rats and these effects may be achieved by activating Notch/Wnt/ß-catenin/RUNX2 signal axis.

Co-modification of calcium phosphate cement to achieve rapid bone regeneration in osteoporotic femoral condyle defect with lithium and aspirin.

Local application of lithium or aspirin with biological scaffold has been identified as a potent means to improve bone formation. In this study, lithium and aspirin modified calcium phosphate cement (Asp-Li/CPC) was prepared, and the feasibility of this biological scaffold in the treatment of osteoporotic bone defect was observed in vivo and in vitro. In vitro experiments confirmed that Asp-Li/CPC had better ability to promote MC3T3-E1 cells differentiation into osteoblasts, osteoblast mineralization and viability, and promote cell expression of ALP, OP, RUNX-2, OC and COL-1 protein than simple CPC or lithium modified CPC by MTT, Alizarin red staining and Western blot evaluation. In vivo experiments confirmed that Asp-Li/CPC presented the strongest effect on bone regeneration and bone mineralization through the comparison with CPC group and Li/CPC group with X-ray images, Micro-CT and Histological evaluation. RT-qPCR analysis showed that Asp-Li/CPC, Li/CPC group and CPC group demonstrated increased BMP2, Smad1, OPG than the OVX group (P<0.05), while Asp-Li/CPC exhibited decreased TNF-α, IFN-γ and RANKL than the OVX group (P<0.05). Experiments in vivo and in vitro show that Asp-Li/CPC is a scheme for rapid repair of femoral condylar defects, and these effects may be achieved by inhibiting local inflammation and through BMP-2/Smad1 and OPG/RANKL signaling pathway.

[Measurement of the maximum corridor parameters of infra acetabular screw and evaluation of the feasibility of screw insertion by digital analysis].

OBJECTIVE: To measure the maximum corridor parameters of the infra acetabular screw and evaluate the feasibility of screw insertion through digital analysis of the acetabular structure. METHODS: The pelvic CT data of 100 patients who received plain pelvic CT scan from April 2013 to June 2015 were retrospectively analyzed. There were 50 males, aged 20 to 84 years, with an average age of (48.42±17.48) years, and 50 females, aged 18 to 87 years, with an average age of (55.02±19.54) years. Patients with acetabular fractures, hip dysplasia, and metal implants in the acetabulum were excluded. Import CT data into Mimics software in DICOM format to generate a three-dimensional model, and find the axialprojection of the infra-acetabular corridor in the middle of the pubis ramus in the inlet view. A virtual screw was placed in the infra-acetabular space and measure the parameters including the diameter and the length of the maximum corridor, the distance from the insertion point to the pubic symphysis, to the anterosuperior iliac spine and to the medial edge of the pelvis. Then import the pelvic model into 3- matic software, establish the pelvic model anterior pelvic plane and median sagittal plane, and measure the angle between the screw axis and the two planes. A minimum corridor diameter of at least 5 mm was defined as a cutoff for placing a 3.5 mm screw, and calculate the screw insertion rate. RESULTS: In 100 cases, 49% of patients had a infra acetabular corridor with a diameter ≥5 mm, and the rate of screw placement in men was significantly higher than that in women. The average diameter of the maximum corridor of infra-acetabular screw was (4.86±1.72) mm, the average length was (94.04±8.29) mm, the average distance from the insertion point to the pubic symphysis was (60.92±4.84) mm, to the anterosuperior iliac spine was (85.15± 6.85) mm, and to the medial edge of the pelvis was (6.12±3.32) mm. The mean angle between the axis of the screw and the median sagittal plane was (-1.38±4.74)°, and the mean angle between the axis of the screw and the anterior pelvic plane was (56.77±7.93)°. There are significant differences between male and female measured parameters, except for the angle between the screw axis and the anterior pelvic plane. There was no statistically significant difference in the maximum corridor parameters of infra-acetabular screw on both sides of the pelvis. CONCLUSION: This study shows that the insertion rate of infra-acetabular screws is low in local patients, and the feasibility of screw insertion should be fully evaluated before surgery.

Effect of alendronate on the femoral metaphyseal defect under carbamazepine in ovariectomized rats.

BACKGROUND: The use of antiepileptic drugs and estrogen deficiency put forward higher requirements for bone defect regeneration. The present study investigated the effects of alendronate (ALN) on femoral bone defect in ovariectomized (OVX) rats under the influence of carbamazepine (CBZ). METHODS: One hundred female SD rats at 3 months of age were either sham-operated or OVX and divided into four groups: sham control (CON); OVX control (OVX); ovariectomized rats treated with CBZ via gavage (75 mg/kg/day; CBZ); ovariectomized rats treated with CBZ plus ALN (2 mg/kg/day; CBZ-ALN). A critical-sized femoral metaphyseal bone defect was established in all female SD rats. Animals from the CBZ and CBZ-ALN groups received drugs by gavage the day after bone defect surgery was performed. After the rats were sacrificed, the defected area located in the distal femur was harvested for evaluation by microcomputed tomography (micro-CT), hematoxylin and eosin (HE) staining, and Masson's trichrome staining. The samples were also analyzed by biomechanics and immunohistochemical evaluation (IHC). Besides, biochemical analysis evaluates all serum samples. RESULTS: The present study showed that ovariectomy changed the microstructural parameters of bone. The use of CBZ further decreased femur bone mass while treatment with ALN prevented bone loss. Compared to OVX and CBZ groups, CBZ-ALN group promoted bone neoformation and enhanced the ultimate load of the femur bone. However, the group of CBZ-ALN did not return to normal levels compared with the CON group. Besides, we noticed that CBZ-ALN group reduced tartrate-resistant acid phosphatase-5b (Tracp-5b) expression and had no significant effect on the expression of osteocalcin (OCN) and type I collagen (Col-I) in IHC compared with CBZ group. Biochemical analysis results presented that systemic delivery of CBZ showed pernicious effects on bone formation and resorption in ovariectomized rats, with the worse effects on C-terminal crosslinked telopeptide of type I collagen (CTX-1). Besides, a significant decrease in CTX-1 levels was observed in CBZ-ALN group as compared to the group of CBZ. CONCLUSION: These results demonstrated that ALN can effectively reverse the effects of CBZ on the microarchitectural properties of bone, and thus can have a positive effect on local bone neoformation in rats with osteoporosis. CLINICAL RELEVANCE: The dose of 2 mg/kg ALN improves the negative effect of prescription of CBZ at 75 mg/kg and promotes bone neoformation of femoral bony deficits.

Parathyroid hormone (1-34) can reverse the negative effect of valproic acid on the osseointegration of titanium rods in ovariectomized rats.

OBJECTIVE: The present work was aimed to evaluate the effect of valproic acid (VPA)，Parathyroid hormone (1-34) (PTH)+VPA on Ti rods osseointegration in ovariectomized rats and further investigation of the possible mechanism. METHODS: The MC3T3-E1 cells were co-cultured with VPA，PTH â€‹+ â€‹VPA and induced to osteogenesis, and the cell viability，mineralization ability were observed by MTT and ALP staining，Alizarin Red staining and Western blotting. Twelve weeks after bilateral ovariectomy, all animals were randomly divided into four groups: group OVX and VPA，PTH â€‹+ â€‹VPA, and all the rats received Ti implants and animals belong to group VPA，PTH â€‹+ â€‹VPA received valproic acid (300 â€‹mg/day), valproic acid (300 â€‹mg/day) plus Parathyroid hormone (1-34) every 3 days (60 â€‹µg/kg), respectively, treatment until death at 12 weeks. Micro-CT, histology, biomechanical testing, bone metabolism index and Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis were used to observe the therapeutic effect and explore the possible mechanism. RESULTS: Results shown that VPA decreased new bone formation around the surface of titanium rods and push-out force other than group OVX. Histology, Micro-CT and biochemical analysis results showed combined application of systemic VPA showed harmful effects than OVX group on bone formation in osteopenia rats, with the worse effects on CTX-1, P1NP and microarchitecture as well as biomechanical parameters by down-regulated gene expression of Runx2, OCN, Smad1, BMP-2 and OPG, while up-regulated RANKL. However, after PTH treatment, the above indicators were significantly improved. CONCLUSIONS: The present study suggests that systemic use of VPA may bring harm to the stability of titanium implants in osteoporosis, PTH can reverse the negative effect of VPA on the osseointegration of titanium rods in ovariectomized rats. TRANSLATIONAL POTENTIAL OF THIS ARTICLE: According to our research, when patients with epilepsy have osteoporotic fractures, after joint replacement or internal fixation, continue to use sodium valproate for anti-epileptic therapy, the possibility of postoperative loosening increases, again on the basis of It can be reversed with the anti-osteoporosis drug parathyroid hormone (1-34).

Aspirin modified strontium-doped ß-tricalcium phosphate can accelerate the healing of femoral metaphyseal defects in ovariectomized rats.

The purpose was to observe whether local administration Strontium (Sr) and Aspirin (Asp) can enhance the efficacy of ß-Tricalcium phosphate(ß-TCP) in the treatment of osteoporotic bone defect. The MC3T3-E1 cells were co-cultured with ß-TCP, Sr/ß-TCP, Asp-Sr/ß-TCP scaffold and induced to osteogenesis, and the cell viability, mineralization ability were observed by MTT, Alizarin Red staining(ARS) and Western blotting(WB). Then this scaffolds were implanted into the femoral epiphysis bone defect model of ovariectomized(OVX) rats for 8 weeks. X-ray, Micro-CT, histology and Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis were used to observe the therapeutic effect and explore the possible mechanism. MTT, ARS results show that the cell mineralization and viability of Asp-Sr/ß-TCP group is significantly higher than Control group, ß-TCP group and Sr/ß-TCP group. Protein expression show that the osteogenic protein expression such as ALP、OP、RUNX-2、OC and COL-1 of Asp-Sr/ß-TCP group is significantly higher than Control group, ß-TCP group and Sr/ß-TCP group. X-ray images, Micro-CT and Histological analysis evaluation show that, group Asp-Sr/ß-TCP presented the strongest effect on bone regeneration and bone mineralization, when compared with ß-TCP group and Sr/ß-TCP group. RT-qPCR analysis show that Asp-Sr/ß-TCP, ß-TCP group and Sr/ß-TCP group showed increased BMP2, Smad1, OPG than the OVX group(p < 0.05), while Asp-Sr/ß-TCP exhibited decreased TNF-α、IFN-γ and RANKL than the OVX group(p < 0.05). Our current study demonstrated that Asp-Sr/ ß-TCP is a scheme for rapid repair of femoral condylar defects, and these effects may be achieved by inhibiting local inflammation and through BMP-2/Smad1 and OPG/RANKL signaling pathway.

Simvastatin can enhance the osseointegration of titanium rods in ovariectomized rats maintenance treatment with valproic acid.

The present work was aimed to evaluate the effect of valproic acid(VPA), simvastatin (SIM)+VPA on Ti(titanium) rods osseointegration in ovariectomized(OVX) rats and further investigation of the possible mechanism. The MC3T3-E1 cells were co-cultured with VPA, SIM + VPA and induced to osteogenesis, and the cell viability, mineralization ability were observed by MTT and ALP staining, Alizarin Red staining and Western blotting. Twelve weeks after bilateral ovariectomy, all animals were randomly divided into three groups: group OVX and VPA, SIM + VPA, and all the rats received Ti implants and animals belong to group VPA, SIM + VPA received valproic acid(300 mg/kg/day), valproic acid(300 mg/kg/day) plus SIM (25 mg/kg/day), respectively, treatment until death at 12 weeks. Micro-CT, histology, biomechanical testing, bone metabolism index and Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis were used to observe the therapeutic effect and explore the possible mechanism. Results shown that VPA decreased new bone formation around the surface of titanium rods and push-out force other than group OVX. Histology, Micro-CT and biochemical analysis results showed combined application of systemic VPA showed harmful effects than OVX group on bone formation in osteopenic rats, with the worse effects on CTX-1, P1NP and microarchitecture as well as biomechanical parameters by down-regulated gene expression of Runx2, OCN, Smad1, BMP-2 and OPG, while up-regulated RANKL. However, after SIM treatment, the above indicators were significantly improved. The present study suggests that systemic use of VPA may bring harm to the stability of titanium implants in osteoporosis, SIM can reverse the negative effect of VPA on the osseointegration of titanium rods in ovariectomized rats.

[Analysis of hidden blood loss and its risk factors in the treatment of osteoporotic vertebral compression fractures with PVP].

OBJECTIVE: To investigate the influencing factors of hidden blood loss (HBL) during the treatment of percutaneous vertebroplasty (PVP). METHODS: The clinical data of 125 patients with osteoporotic vertebral compression fractures (OVCFs) treated with percutaneous vertebroplasty from March 2016 to December 2017 were retrospectively analyzed. All patients underwent X rays of the AP and lateral lumbar spine, double oblique, and dynamic positions. Lumbar spine CT, MRI, and dual energy X ray bone densitometer (DXA) were used to confirm the diagnosis. There were 55 males and 70 females, 10 cases of thoracic vertebrae, 89 cases of thoracolumbar vertebrae, 26 cases of lumbar vertebrae, 87 cases with single segment, 29 cases with double segment,and 9 cases with 3 segments. The vertebral compression height ratios of 67 patients were less than 1 / 3, and the ratios for 41 patients were from 1 / 3 to 2 / 3,for 17 patients were more than 2 / 3. Blood routine examination were performed before and 3 days after surgery to analyze hidden blood loss and to explore its risk factors. RESULTS: The average hidden blood loss was (317±156) ml in 125 patients. Multiple linear regression analysis revealed a history of diabetes(P=0.011),surgical segments(P=0.036),number of segments (P<0.001),vertebral height loss rate (P=0.002),vertebral height recovery rate (P<0.001) and bone cement leakage rate (P=0.003) were positively correlated with hidden blood loss. Moreover,it was found that the blood loss was higher in those with higher vertebral height loss rate than in those with lower vertebral height loss rate, and the blood loss was higher in those with good vertebral height recovery than those with poor vertebral height recovery. Additionally,the cement leakage was also an important factor in increasing hidden blood loss. However,there was no significant correlation between bone mineral density(P=0.814) or history of hypertension(P=0.055) and hidden blood loss. CONCLUSION: Patients with OVCFs have a large amount of hidden blood loss after PVP treatment, which needs attention. At the same time, the history of diabetes, surgical segments, number of segments, bone cement leakage rate, vertebral height loss rate and vertebral height recovery rate are the risk factors for hidden blood loss.