Drug loaded nanoparticles (NPs) were developed as a model intra-articular injection (IAI) formulation to mitigate early stage osteoarthritis (OA). Different types of celecoxib-loaded nanoparticles were prepared by a hybrid method that combines homogenization and solvent evaporation. The hydrodynamic diameter of the nanoparticles prepared were approximately 200 nm (PLLA: 238 ± 19 nm; PCL: 249 ± 28 nm; PLA: 252 ± 18 nm; PMMA: 234 ± 21), and zeta potential were about -40 mV (PLLA: -45.3 ± 2.3 mV; PCL: -38.0 ± 0.9 mV; PLA: -44.4 ± 3.2 mV; PMMA: -45.5 ± 2.7 mV). Our friction data evidences that nanoparticles could improve considerably the lubrication between a stainless steel sphere and a silicone elastomer that were used as model substrates. Quartz Crystal Microbalance (QCM) and Atomic Force Microscope (AFM) measurements were carried out to unravel the lubrication mechanism. The magnitude and amount of NPs adsorbed on the surface determines the effect of lubrication. Drug release experiment suggests that nanoparticles could release up to more than one week, when being compared with free celecoxib. NPs formulation exhibited excellent biocompatibility in cytotoxicity of chondrocytes experiment.

Aims:Immune cells exert influence on skeletal homeostasis, and re-establishing metabolic equilibrium is central to the management of steroid-induced osteonecrosis of the femoral head (SIONFH). However, the osteoimmune mechanisms underpinning this pathology remain largely under-researched. This study aimed to delineate these mechanisms, thereby informing early therapeutic strategies to restore bone homeostasis. Methods:We identified the key immune cell subsets associated with SIONFH, and investigated their upstream regulatory factors and downstream effector molecules by integrating multiomics analyses (samples derived from human peripheral blood, femoral head tissues, and rat peripheral blood), mining of the GSE123568 dataset, and performing in vivo and in vitro experiments. Results:Clinical transcriptomics revealed enrichment of immune-related pathways, with ssGSEA consistently highlighting activated CD8+ T cells and Th1 cells. Correlation analyses demonstrated a stronger association between T cells and osteoblasts than osteoclasts (r = 0.8728 vs r = -0.065). Staphylococcal enterotoxin C2 (sec2) activated T cells both in vitro and in vivo, thereby augmenting osteogenic markers, enhancing bone marrow stromal cell (BMSC) differentiation, and elevating T cell-derived interferon gamma (IFNγ). Mechanistically, IFNγ facilitated signal transducer and activator of transcription 1 (STAT1)-runt-related transcription factor 2 (Runx2) dissociation and Runx2 nuclear translocation, thereby potentiating osteogenesis. Multiomics and functional studies identified neuropilin 1 (NRP1) as a critical IFNγ/T cell-associated protein, downregulated by staphylococcal enterotoxin C2 (sec2). Pharmacological activation of NRP1 with certepetide validated its role in modulating IFNγ secretion and downstream signalling. Glucocorticoids suppress IFNγ production in T cells and weaken NRP1/IFNγ-driven osteogenic differentiation. Ultimately, sec2 reshaped antigen-presenting cell-mediated regulation of the T cell-NRP1/IFNγ axis, promoting bone formation and mitigating SIONFH. Conclusion:Glucocorticoids suppress T cell-derived IFNγ via NRP1 upregulation, thereby impairing Runx2 nuclear translocation and BMSC osteogenesis. Sec2 counteracts this cascade through antigen-presenting cell modulation, restoring the NRP1/IFNγ axis to preserve femoral head integrity.

BACKGROUND:Oestrogen-deficient osteoporosis features an imbalanced bone formation-resorption coupling with excessive osteoclast activation and impaired osteoblast function. Compounds that bidirectionally regulate bone metabolism remain rare among natural small molecules. Cajaninstilbene acid (CSA) from Cajanus cajan leaves exerts regulatory effects on bone metabolism and anti-inflammatory activity, but its mechanism in restoring bone homeostasis via intercellular mitochondrial transfer remains unclear. PURPOSE:To investigate the therapeutic effect of CSA on oestrogen-deficient osteoporosis and reveal its molecular mechanism by targeting TNF-α-mediated mitochondrial transfer to rebalance osteogenesis and osteoclastogenesis. MATERIALS:Ovariectomised (OVX) mice were used as the estrogen-deficient osteoporosis model and treated with CSA for 6 weeks. Bone microstructure and metabolism were evaluated by micro-computed tomography (micro-CT), histological staining and immunohistochemistry (IHC). Primary bone marrow macrophages (BMMs) and bone marrow mesenchymal stem cells (BMSCs) were cultured for osteoclastic and osteogenic differentiation. Differentiation was assessed by tartrate-resistant acid phosphatase (TRAcP), alkaline phosphatase (ALP) and alizarin red staining (ARS). Key targets were screened by transcriptomic analysis and validated by molecular docking and surface plasmon resonance (SPR). Mitochondrial transfer and activity were observed by co-culture, fluorescence labelling and JC-1 staining. Protein and gene expression were determined by Western blot (WB) and quantitative real-time polymerase chain reaction (qPCR). RESULTS:CSA significantly increased bone mineral density and improved trabecular microarchitecture in OVX mice without obvious hepatorenal toxicity. In vitro, CSA dose-dependently suppressed RANKL-induced osteoclastogenesis by downregulating NFATc1 and CTSK, while enhancing osteoblast differentiation by upregulating RUNX2, OCN and OPG. Mechanistically, CSA directly bound and inhibited TNF-α, upregulated the mitochondrial transporter MIRO1, and restored mitochondrial transfer from osteoblasts to osteoclasts, reversing the disrupted bone coupling balance. CONCLUSION:CSA bidirectionally inhibits bone resorption and promotes bone formation by blocking TNF-α signalling and restoring MIRO1-mediated mitochondrial transfer, effectively ameliorating oestrogen-deficient osteoporosis. This study provides pharmacological support and novel mechanistic insights for CSA as a promising natural candidate for osteoporosis treatment.

BACKGROUND:Ferroptosis, an iron-dependent cell death mechanism, is a crucial factor in the progression of knee osteoarthritis (KOA), characterized by the excessive accumulation of lipid peroxides. Clinical and animal studies demonstrated increased iron deposition in KOA joints, primarily inside the subchondral bone marrow, synovium, and cartilage. Didymin, a flavonoid glycoside derived from Citrus species, demonstrates significant anti-inflammatory and antioxidant properties; however, its function in KOA remains unexplored. PURPOSE:Using metabolomics in conjunction with network pharmacology, molecular docking (MD), molecular dynamics simulation (MDS), surface plasmon resonance (SPR) assay, and in vivo experimental validation, this study sought to elucidate the therapeutic effects and potential mechanism by which the natural flavonoid Didymin mitigates KOA progression by targeting ferroptosis. MATERIALS AND METHODS:This study established an animal model of knee osteoarthritis (KOA). The rats received oral administration with Didymin at 0.7 mg/(kg·day) or 2.8 mg/(kg·day) weekly. The effects of Didymin on KOA cartilage and subchondral was evaluated using micro-CT, hematoxylin and eosin (H&E), safranin O/fast green (SO/FG), and toluidine blue (TB) staining, and immunohistochemistry (IHC). In vitro, CCK-8 assays and chondrocyte staining assessed cell proliferation and extracellular matrix metabolism to evaluate Didymin's effects on ferroptosis in primary chondrocytes induced by ferrous ammonium citrate and IL-1β. Subsequently, metabolomics was employed to identify differential metabolites, whilst integrating network pharmacology and disease gene target analysis to characterise protein targets in KOA and corresponding targets for Didymin. MD assessed interactions between Didymin and targets, with findings validated via MDS. In vitro SPR experiments directly validated these interactions. Downstream targets were further explored using protein-protein kinetic simulations and co-immunoprecipitation (Co-IP) techniques. Concurrently, immunofluorescence (IF), polymerase chain reaction (PCR), and Western blotting (WB) were employed to elucidate the mechanism by which Didymin ameliorates cartilage degeneration in knee osteoarthritis. RESULTS:In an iron-overload KOA rat model, Didymin treatment mitigated cartilage degradation and subchondral bone loss, improved ECM synthesis, and restored the expression of the antioxidant proteins nuclear factor E2-related factor 2 (Nrf2) and glutathione peroxidase 4 (GPX4). In vitro, Didymin suppressed ferroptosis in primary chondrocytes induced by ferric ammonium citrate and IL-1β. Metabolomics identified 11-hydroxyeicosatetraenoic acid (11-HETE) as a key differential metabolite in the KOA model. By combining metabolite-protein interaction networks, GSK3B is an upstream regulator of 11-HETE production. Further qPCR analysis of 5-LOX expression profiling identified it as a primary candidate. In vitro and in vivo experiments suggested that Didymin reduced the glycogen synthase kinase-3β (GSK3B) activation, resulting in the downregulation of 5-LOX expression and 11-HETE generation. The effect was validated using the GSK3B-specific inhibitor LY2090314, which mimicked Didymin's suppression of 5-LOX/11-HETE. Consequently, Didymin inhibited lipid peroxidation cascades by simultaneously suppressing 11-HETE generation and enhancing Nrf2/GPX4 activity. CONCLUSION:Our findings identify Didymin as a natural flavonoid compound that combats KOA through the GSK3B/5-LOX/11-HETE signaling pathway, offering a novel therapeutic strategy to alleviate ferroptosis-mediated cartilage destruction.

The death of osteoblasts induced by glucocorticoid (GC)-mediated oxidative stress plays a crucial role in the development of steroid-induced osteonecrosis of the femoral head (SIONFH). Improving bone formation driven by osteoblasts has shown promising outcomes in the prognosis of SIONFH. Isovitexin has demonstrated antioxidant properties, but its therapeutic effects on GC-induced oxidative stress and SIONFH remain unexplored. In this study, we analyzed clinical samples obtained from SIONFH patients using proteomic and bioinformatic approaches. We found an imbalance in mitochondrial homeostasis and ferroptosis-induced impairment of osteogenic capacity in SIONFH. Subsequently, we investigated the cause-and-effect relationship between mitochondria and ferroptosis, as well as the regulatory role of mitophagy in maintaining mitochondrial homeostasis and controlling ferroptosis. We then identified the critical involvement of SIRT3 in modulating mitochondrial homeostasis and ferroptosis. Furthermore, molecular docking and co-immunoprecipitation confirmed the strong interaction between SIRT3 and BNIP3. Strikingly, restoring SIRT3 expression significantly inhibited pathological mitophagy mediated by the BNIP3/NIX pathway. Additionally, we discovered that Isovitexin, by promoting SIRT3 expression, effectively regulated mitophagy, preserved mitochondrial homeostasis in osteoblasts, suppressed ferroptosis, and restored osteogenic capacity, leading to remarkable improvements in SIONFH. These findings reveal the effects and molecular mechanisms of Isovitexin on SIONFH and highlight the potential of targeting SIRT3 as a promising strategy to suppress mitophagy-mediated ferroptosis in osteoblasts and against SIONFH.

BACKGROUND:Compelling evidence has implicated osteoblast ferroptosis as a critical contributor to the pathogenesis of glucocorticoid-induced osteoporosis (GIOP). However, the underlying regulatory mechanisms remain poorly understood. METHODS:In the glucocorticoids (GCs)-induced GIOP rat model, both osteoblast dysfunction and ferroptosis markers were assessed. Ferroptosis was inhibited with deferoxamine (DFO). Transcriptomic profiling was performed to analyze the correlation between mitophagy and SIRT3 levels. In MC3T3-E1 cells exposed to GCs, we examined key mitophagy markers PINK1 and PARKIN, mitochondrial function, and SIRT3 expression. Treatments included DFO, mitophagy inhibitors (Mdivi-1), and SIRT3 agonists (Nicotinamide riboside chloride). RESULTS:In the GIOP rat model, significant osteoblast dysfunction and elevated ferroptosis markers were observed. Although DFO treatment inhibited ferroptosis, it failed to restore osteogenesis, suggesting the involvement of additional regulatory mechanisms in osteogenic function regulation. Transcriptomic profiling highlighted a robust correlation between mitophagy and SIRT3 levels in GIOP. In GC-exposed MC3T3-E1 cells, key mitophagy markers PINK1 and PARKIN were upregulated, mitochondrial function was impaired, and SIRT3 expression was significantly reduced. Notably, while DFO treatment did not restore mitochondrial homeostasis, the application of Mdivi-1 (mitophagy inhibitor) and Nicotinamide riboside chloride (SIRT3 agonists) effectively alleviated ferroptosis and restored mitochondrial function. CONCLUSIONS:SIRT3 regulates ferroptosis by inhibiting excessive mitophagy in osteoblasts, providing a novel mechanistic pathway for mitigating GIOP. These findings suggest that SIRT3 represents a critical regulator of mitophagy-dependent ferroptosis and a potential therapeutic target for GIOP.

ObjectiveTo develop the stepped exercise program for patients with pelvic tilt after the initial unilateral total hip arthroplasty(THA),and to provide evidence⁃based guidance for postoperative rehabilitation.MethodsDrawing upon clinical experience,comprehensive literature review, and expert consultation,a stepped exercise program for patients with pelvic tilt after the initial unilateral THA was systematically developed.ResultsA panel of 22 experts participated in two rounds of inquiry,achieving a 100% response rate in both rounds.The expert authority coefficient was 0.89,indicating high reliability.The coefficient of variation for indicators ranged from 0.00 to 0.16 in the first round and 0.00 to 0.08 in the second round.Kendall's coefficient of concordance was 0.105(P<0.05) in the first round and increased to 0.233(P<0.05) in the second round.The final program included five first⁃level indicators,20 second⁃level indicators, and 25 third⁃level indicators.ConclusionsThe developed stepped exercise program for patients with pelvic tilt after the initial unilateral total hip arthroplasty was scientifically sound,content⁃wise comprehensive,and clinically applicable.It provided a reliable reference and practical guidance for postoperative rehabilitation management of patients.

Bone marrow edema (BME), a notable manifestation during the progression of osteonecrosis of the femoral head (ONFH), exhibits significant associations with femoral head collapse, pain, and prognosis, howeverits’ pathogenesis remains underexplored. In this study, specimens from patients undergoing total hip arthroplasty (THA) were analyzed. The results revealed significantly higher Visual Analog Scale (VAS) scores and CT low-density area ratio in the BME group compared to the control group. Furthermore, Sirius Red staining exhibited fibrotic tissue in both necrotic and sclerotic areas, with more pronounced effects in the BME group. Meanwhile, data-independent Acquisition (DIA) proteomics technology was utilized to identify differentially expressed proteins (DEPs) within bone tissue. 141, 299 and 852 DEPs were identified in femoral neck, necrotic and sclerotic regions, respectively. Immune responses, inflammatory reactions and oxidative stress were markedly altered in ONFH cases with BME. In bone tissue, the levels of malondialdehyde (MDA) and proteins associated with osteoclast activity were found to be elevated in the BME group. In conclusion, BME in ONFH at pericollapse stage is associated with inflammation, fibrosis, heightened oxidative stress and increased osteoclast activity. These factors collectively elevated the risk of collapse or re-collapse. Targeted interventions aimed at neutralizing these risk factors show potential in slowing down the progression of the disease.

OBJECTIVES:Steroid-induced osteonecrosis of the femoral head (SIONFH) represents a global therapeutic challenge, and its pathogenesis requires in-depth investigation. While oxidative stress is recognized as a critical contributor to SIONFH, the underlying mechanism remains incompletely elucidated. METHODS:In this study, multi-omics analysis of clinical specimens was performed to screen for oxidative stress-related molecules in SIONFH and identify hub molecules among them. Subsequently, the functional significance of these hub molecules was validated via Gene Ontology (GO) analysis and both in vitro and in vivo experiments. Furthermore, in vitro and in vivo experiments were conducted to further confirm the correlations between hub molecules, oxidative stress, and osteoclast differentiation. RESULTS:RNA-seq analysis identified 1,107 differentially expressed genes, with PRXL2A designated as an oxidative stress-related hub gene. Subsequent protein DIA analysis detected 139 differentially expressed proteins, further confirming PRXL2A as an oxidative stress-associated hub protein. Functional exploration revealed that PRXL2A is involved in biological processes such as oxidative stress and osteoclast differentiation. When antioxidants were applied to osteoclasts, results from TRAP staining, RT-PCR, and other assays indicated that PRXL2A expression decreased with elevated oxidative stress and also declined as osteoclast differentiation increased. Finally, in vivo experiments further validated the negative correlations between PRXL2A, oxidative stress, and osteoclast differentiation. CONCLUSION:This study demonstrates that enhanced oxidative stress in SIONFH patients reduces PRXL2A expression, which may promote osteoclast differentiation, thereby accelerating local femoral head bone destruction and contributing to SIONFH progression.

Hyperactive osteoclasts and hypoactive osteoblasts usually result in osteolytic conditions such as estrogen-deficiency bone loss. Few natural compounds that both attenuating bone resorption and enhancing bone formation could exert effects on this imbalance. 5-Deoxycajanin (5-D), an isoflavonoid extracted from Cajan leaf with estrogen-like properties, were found to have beneficial pharmacological effects on rebalancing the activities of osteoclasts and osteoblasts. This study revealed that 5-D at the same concentration could inhibit osteoclastogenesis of BMMs and promoted osteoblast differentiation of BMSCs. 5-D not only attenuated the fluorescent formation of RANKL-induced F-actin belts and NFATc1, but also activated ALP and RUNX2 expressions. As to downstream factor expressions, 5-D could block osteoclast-specific genes and proteins including NFATc1 and CTSK, while increased osteogenic genes and proteins including OPG and OCN, as confirmed by Real-time PCR and Western Blotting. Additionally, the network pharmacology and molecular docking identified the involvement of 5-D in the MIF and MAPK signaling pathways and the stable binding between 5-D and MAPK2K1. Further Western blot studies showed that 5-D decreased the phosphorylation of p38 and ERK in osteoclasts, but promoted these phosphorylations in osteoblasts. In a female C57BL/6J mouse model of estrogen deficiency-induced bone loss, 5-D demonstrated efficacy in enhancing BMD through attenuating osteoclast activities and promoting osteogenesis. These results underscore the potential application of 5-D on treating osteolysis resulting from hyperactive osteoclasts and hypoactive osteoblasts, shedding light on modulating osteoclast-osteoblast homeostasis.

Background/objectiveAs the pivotal cellular mediators of bone resorption and pathological bone remodeling, osteoclasts have emerged as a prominent target for anti-resorptive interventions. Pinocembrin (PIN), a predominant flavonoid found in damiana, honey, fingerroot, and propolis, has been recognized for its potential therapeutic effects in osteolysis. The purpose of our project is to investigate the potential of PIN to prevent bone resorption in ovariectomized (OVX) mice by suppressing osteoclast production through its underlying mechanisms.MethodsThe study commenced by employing protein-ligand molecular docking to ascertain the specific interaction between PIN and nuclear factor-κB (NF-κB) ligand (RANKL). Subsequently, PIN was introduced to bone marrow macrophages (BMMs) under the stimulation of RANKL. The impact of PIN on osteoclastic activity was assessed through the utilization of a positive TRAcP staining kit and a hydroxyapatite resorption assay. Furthermore, the study investigated the generation of reactive oxygen species (ROS) in osteoclasts induced by RANKL using H2DCFDA. To delve deeper into the underlying mechanisms, molecular cascades triggered by RANKL, including NF-κB, ROS, calcium oscillations, and NFATc1-mediated signaling pathways, were explored using Luciferase gene report, western blot analysis, and quantitative real-time polymerase chain reaction. Moreover, an estrogen-deficient osteoporosis murine model was established to evaluate the therapeutic effects of PIN in vivo.ResultsIn this study, we elucidated the profound inhibitory effects of PIN on osteoclastogenesis and bone resorption, achieved through repression of NF-κB and NFATc1-mediated signaling pathways. Notably, PIN also exhibited potent anti-oxidative properties by mitigating RANKL-induced ROS generation and augmenting activities of ROS-scavenging enzymes, ultimately leading to a reduction in intracellular ROS levels. Moreover, PIN effectively abrogated the expression of osteoclast-specific marker genes (Acp5, Cathepsin K, Atp6v0d2, Nfatc1, c-fos, and Mmp9), further underscoring its inhibitory impact on osteoclast differentiation and function. Additionally, employing an in vivo mouse model, we demonstrated that PIN effectively prevented osteoclast-induced bone loss resultant from estrogen deficiency.ConclusionOur findings highlight the potent inhibitory effects of PIN on osteoclastogenesis, bone resorption, and RANKL-induced signaling pathways, thereby establishing PIN as a promising therapeutic candidate for the prevention and management of osteolytic bone diseases.The translational potential of this articlePIN serves as a promising therapeutic agent for the prevention and management of osteolytic bone diseases and holds promise for future clinical applications in addressing conditions characterized by excessive bone resorption. PIN is a natural compound found in various sources, including damiana, honey, fingerroot, and propolis. Its widespread availability and potential for therapeutic use make it an attractive candidate for further investigation and development as a clinical intervention.

Objectives The collapse of femoral head is a serious symptom of osteonecrosis of the femoral head (ONFH), resulting in hip pain and deformity. However, it is hardly possible to reestablish the femoral head nonoperatively once the collapse happens. Predicting femoral head collapse is of great value for the prognosis of ONFH. This study aimed to develop a new method to quantify the preserved thickness of femoral head and to assess its diagnostic contribution in predicting femoral head collapse on plain radiographs. Methods This was a single‐center retrospective study. A total of 101 hips (85 patients) with ARCO stage II from January 2008 to December 2016 were included in this study. The preserved thickness was measured on standard anteroposterior (AP) and frog‐leg (FL) radiographs. The anteroposterior view's preserved thickness ratio (APTR) and the frog‐leg view's preserved thickness ratio (FPTR) were calculated to show the preserved thickness ratio of the femoral head anteriorly and laterally. Univariate and multivariate logistic regression was performed to determine the risk factors for collapse. Sensitivity, specificity, and cut‐off values for APTR and FPTR were determined by the receiver operating characteristic (ROC) curve analysis. Kaplan–Meier (K‐M) analysis was applied to determine femoral head survival in ONFH patients. Results The mean age of the 27 females and 58 males was 38.93 years old. The mean follow‐up time was 74.62 (36–124) months in the non‐collapse group and 18.66 (3–82) months in the collapse group. Femoral head collapse was observed in 62 hips during the follow‐up period. Logistic regression analysis and ROC results showed that APTR <24.79% and FPTR <10.62% were significantly correlated with femoral head collapse. The Kaplan–Meier survival curve suggested that the overall survival rate of APTR ≥24.79% was 68.2% at 5 and 10 years and FPTR ≥10.62% was 71.63% at 5 and 10 years. At the last follow‐up, 26 hips had collapse on the anterior side of the femoral head, 12 hips occurred on the lateral side, and 24 hips happened to collapse on both anterior and lateral sides. Conclusion Femoral head collapse predominantly occurred anteriorly rather than laterally in ONFH patients. The measurements of APTR and FPTR have noticeable implications for the prediction of femoral head collapse, and contribute to the selection of treatment options for ONFH patients with types B and C1 according to the JIC classification.

BACKGROUND:Studies have shown that imbalance of bone metabolism during glucocorticoid-induced osteonecrosis of the femoral head necrosis is closely related to oxidative stress. OBJECTIVE:To investigate the pathological mechanism by which oxidative stress-induced ferroptosis promote apoptosis in osteoblasts involved in steroid-induced osteonecrosis of the femoral head. METHODS:General data and serum specimens were collected from 47 patients with steroid-induced osteonecrosis of the femoral head.In addition,six femoral head specimens were collected from these patients.According to the Association Research Circulation Osseous(ARCO)staging system,serum specimens were grouped into ARCO Ⅱ,Ⅲ,and IV,while femoral head specimens were classified into ARCO Ⅲ and IV.Serum levels of malondialdehyde and superoxide dismutase 1 were measured.The protein expression of superoxide dismutase 1,glutathione peroxidase 4,Bcl-2 in the femoral head was detected and verified by Data independent acquisition(DIA)for quantitative sequencing,western blot and alkaline phosphate detection. RESULTS AND CONCLUSION:The ARCO stage of patients with steroid-induced osteonecrosis of the femoral head was independent of age,sex and necrotic side.The serum levels of malondialdehyde and superoxide dismutase 1 were higher in patients with ARCO stage Ⅲ compared with those with ARCO stage Ⅱ and IV.The results of DIA protein quantification showed that the function of differential proteins was mainly related to redox.The levels of superoxide dismutase 1,glutathione peroxidase 4,and Bcl-2 in the necrotic region were lower than in the normal region,as well as lower in ARCO stage IV than in ARCO stage Ⅲ.Western blot verified the results of DIA protein quantification.The alkaline phosphatase activity was lower in the necrotic region than in the normal region,as well as lower in ARCO stage IV than in ARCO stage Ⅲ.In the necrotic and sclerotic regions,the function of differential proteins was also related to redox,and superoxide dismutase 1,glutathione peroxidase 4,Bcl-2 protein expression and alkaline phosphatase activity were lower in the necrotic area than in the sclerotic region,as well as lower in ARCO stage IV than in ARCO stage Ⅲ.To conclude,glucocorticoids can influence the progression of steroid-induced osteonecrosis of the femoral head by upregulating oxidative stress levels,inducing osteoblast ferroptosis,and inhibiting osteogenic function.

ObjectiveOsteonecrosis of the femoral head (ONFH) is a disabling and intractable orthopedic disease largely affecting young and middle-aged groups. Current standard of treatment relies on the collapse of femoral head as a predictor for prognosis. However, a wide range of variability in repair potentials is observed in patients with femoral head collapse. Therefore, the present study aimed to evaluate the accuracy of femoral head collapse as a predictor and to propose the necrotic lesion boundary as a novel yet reliable measure for ONFH prognosis.MethodsA retrospective cross-sectional study was conducted at the First Affiliated Hospital of Guangzhou University of Chinese Medicine, 203 hips with ONFH from 134 patients were included. The occurrences and progression of femoral head collapse were recorded. Necrosis lesion boundary was quantified and classified for each case based on anteroposterior view intact ratio (APIR) and the frog-leg view intact ratio (FLIR) as independent variables. Dependent variables were defined as progressive collapse or terminal collapse for Association Research Circulation Osseous (ARCO) stage II and III respectively. Logistic regression analysis, Receiver Operating Characteristic (ROC) curve and Kaplan-Meier (K-M) survival analysis was performed and results were interpreted.ResultsOut of the 106 hips in ARCO stage II, 31 hips collapsed with further progression, while 75 hips had no collapse or collapse with repair of the necrotic areas. Out of the 97 hips in ARCO stage IIIA, the collapse continued to progress in 58 hips while the necrotic areas were repaired in 39 hips. Logistic regression analysis demonstrated that both APIR and FLIR, were independent risk factors. Further ROC curve analysis indicated that the cutoff values of APIR and FLIR could be considered as indications for evaluating the prognosis of ONFH. Contrary to the traditional view of poor prognosis after femoral head collapse, K-M survival analysis demonstrated a high value of APIR and FLIR for ONFH prognosis.ConclusionThe present study found that the occurrence of collapse is an oversimplified predictor for ONFH prognosis. The collapse of the femoral head in ONFH does not predict a poor prognosis. The necrosis lesion boundary has a high value in predicting ONFH prognosis and informing clinical treatment strategies.

Purposes The aim of this study was to construct a lateral classification system for nontraumatic osteonecrosis of femoral head (NONFH) through three-dimensional reconstruction of the necrotic area to assist in evaluating the prognosis of patients with JIC type C1. Methods Retrospective analysis of patients with JIC type C1 NONFH from January 2018 to December 2020. All patients were followed up for more than 3.5 years. The patients were divided into collapse group and non-collapse group according to whether the femoral head collapsed during the follow-up.Lateral classification system for femoral head necrosis is constructed through three-dimensional reconstruction of the necrotic area.Comparison of lateral classification system,midsagittal necrosis angle(MNA)and general data between the two groups.Furthermore, ROC curve analysis and survival analysis were performed. Results 318 patients were included in this study.There was a significant difference between the two groups in the lateral classification system ( P < 0.05). In addition, the MNA in the collapsed group was significantly greater than that in the non-collapse group( P < 0.05). As revealed by the results of ROC analysis, the cutoff point of MNA was 104.5° ( P < 0.05).According to the survivorship analysis, the mean survival time of the hips of patients with MNA less than 104.5°was greater than that of patients with MNA over 104.5° ( P < 0.05). The survival rates of 3.5 years femoral head were 45.8%, 33.7%, 14.8%, 93.0%, and 100% for lateral classification system 1, 2, 3, 4, and 5, respectively. Conclusion Necrosis involving the anterior aspect of the femoral head is an important risk factor for collapse. The Lateral classification system can effectively predict the femoral head collapse in JIC C1 type NONFH patients, supplementing the deficiency of JIC classification in evaluating the front of the femoral head.

Postmenopausal osteoporosis, a chronic condition that predominantly affects postmenopausal women, presents a significant impediment to their overall well-being. The condition arises from estrogen deficiency, leading to enhanced osteoclast activity. Salvia miltiorrhiza, a well-established Chinese herbal medicine with a history of clinical use for osteoporosis treatment, contains diverse active constituents that have shown inhibitory effects on osteoclast formation and bone loss. Dihydrotanshinone I (DTI), a phenanthrenonequinone compound derived from the root of Salvia miltiorrhiza, has been identified as a potential therapeutic agent, although its mechanism of action on osteoclasts remains elusive. In this study, we aimed to elucidate the inhibitory potential of DTI on RANKL-induced osteoclastogenesis. We observed the ability of DTI to effectively impede the expression of key osteoclast-specific genes and proteins, as assessed by Real-time PCR and Western Blotting analyses. Mechanistically, DTI exerted its inhibitory effects on osteoclast formation by modulating critical signaling pathways including NF-κB, ERK, and calcium ion signaling. Notably, DTI intervention disrupted the nuclear translocation and subsequent transcriptional activity of the NFATc1, thus providing mechanistic insights into its inhibitory role in osteoclastogenesis. To further assess the therapeutic potential of DTI, we employed an ovariectomized osteoporosis animal model to examine its impact on bone loss. Encouragingly, DTI demonstrated efficacy in mitigating bone loss induced by estrogen deficiency. In conclusion, our investigation elucidates the ability of DTI to regulate multiple signaling pathways activated by RANKL, leading to the inhibition of osteoclast formation and prevention of estrogen-deficiency osteoporosis. Consequently, DTI emerges as a promising candidate for the treatment of osteoporosis.

Background For femoral neck fractures in young and middle-aged patients, both fibula allograft with cannulated screw fixation and ordinary cannulated screw fixation are clinically effective treatments. However, for unstable femoral neck fractures, ordinary cannulated screw fixation is characterized by a high risk of postoperative complications and a high rate of mechanical failure after internal fixation. For this study, we systematically compared the long-term efficacy and postoperative complications of these two procedures. Methods A total of 156 subjects diagnosed as femoral neck fractures participated in our study. Subjects in the combination group underwent fibula allograft with cannulated screw fixation ( n = 76), and those in the control group were treated with ordinary cannulated screw fixation ( n = 80). Baseline characteristics, perioperative outcomes, Harris hip score (HHS) and EuroQoL five-dimension questionnaire (EQ-5D); and the incidence of postoperative and bone healing complications in the two groups were recorded and compared. Results The average follow-up time was more than 10 years. Intra-operative blood loss significantly increased in the combination group compared with the control group ( P < 0.05). There were significantly improved performances in healing time, the time course of recovery of full-weight-bearing stepping, HHS and EQ-5D scores in the combination group compared with the control group ( P < 0.05). Besides, the incidence rates of femoral head necrosis, nonunion, femoral neck shortening and total hip replacement were significantly lower in the combination group than those in the control group ( P < 0.05). Conclusion Fibula allograft with cannulated screw fixation shows a better long-term therapeutic effect than ordinary cannulated screw fixation for femoral neck fractures in young and middle-aged patients. Patients receiving the combination strategy have faster and high-quality functional recovery after femoral neck fractures and a lower incidence rate of postoperative complications.

Osteonecrosis of the femoral head (ONFH) is a progressive disease with complex etiology, unclear pathogenesis and lack of optimal treatment.This diseases often causeship pain and functionalimpairment, and is mainlyseen in young and middle-aged patients. Current treatment for ONFH is mostly osteogenic and angiogenic. However, a single treatment can only have a positive effect on early ONFH and does not address the fundamental challenge, which is bone resorption and subchondral bone collapse in an ischemic environment. With the development of modern medicalt echnology, cell therapy for ONFH has become a hot topic of current research. This article reviewed the current therapeutic effects of stem cells in the field of ONFH. More and more studies have confirmed the efficacy and feasibility of stem cell therapy for ONFH. Therefore, the source, quantity and safety of the cells need to be further explored.

Supercritical anti-solvent fluidized bed (SAS-FB) technology can be applied to reduce particle size, prevent particle aggregation, and improve the dissolution and bioavailability of poorly soluble drugs. In this work, drug-loaded microparticles of three similar structures, the flavonoids luteolin (LUT), naringenin (NGR), and dihy-dromyricetin (DMY) were prepared using SAS-FB technology, to explore its effect on the coating of flavonoid particles. Operating temperature, pressure, carrier, solvent, and concentration of drug solution were investigated for their effects on the yield and dissolution of flavonoid particles. The results showed that temperature, pressure, carrier, and drug solution concentration have a large effect on yield. Within the study range, low supercritical CO2 density at higher temperature and lower pressure, a larger surface area carrier, and moderate drug solution concentration led to a higher yield. The effect of the solvent on the yield of flavonoids is a result of multiple factors. Scanning electron microscopy (SEM) images showed that the drug-loaded particles prepared from different carriers and solvents have different precipitations pattern on the carrier surface, and their particle sizes were smaller than unprocessed particles and those prepared by the SAS process. Fluorescence microscopy (FM) results showed that the flavonoids were uniformly coated on the carrier. X-ray powder diffraction (XRPD) results showed that the crystalline morphology of SAS-FB particles remained unchanged after the SAS-FB process, although the diffraction peak intensity decreased. The cumulative dissolution of SAS-FB particles was more than four times faster in the first 5 min than that of the unprocessed flavonoids. The antioxidant activity of SAS-FB processed LUT, NGR and DMY was 1.89-3.78 times, 4.92-10.68 times and 0.99-2.57 times higher than that of the untreated flavonoids, respectively. The approach provides a reference for the application of SAS-FB tech-nology in flavonoids.