Search Results (984)

The most common complication of active brucellosis in humans is osteoarticular injury. In the bone marrow microenvironment, mesenchymal stem cells (MSCs) can differentiate into either adipocytes or osteoblasts, and this balance is tightly regulated because an increase in adipogenesis may negatively affect bone formation and favor bone loss. The differentiation of MSCs into adipocytes or osteoblasts is tightly regulated by mechanisms that promote cell fate toward one lineage while repressing the other. Our study demonstrated that Brucella abortus infects MSCs but does not affect the deposition of organic and mineral matrix during osteoblast differentiation. However, the infection upregulates Receptor Activator of Nuclear Factor Kappa-B Ligand (RANKL) expression in osteoblasts, which may contribute to osteoclast activation and bone resorption. Conversely, B. abortus infection significantly influences adipocyte differentiation by modulating lipolysis, lipogenesis, and interactions between lipid droplets and mitochondria. This leads to increased cellular cholesterol levels and reduced intracellular triglycerides, accompanied by glycerol release. These changes result in more differentiated adipocytes and larger lipid droplets. Consequently, we observed increased IL-6 secretion and a higher leptin/adiponectin ratio. Importantly, these effects were independent of a functional type IV secretion system (T4SS), as purified Brucella DNA fully reproduced the adipogenic phenotype. Moreover, inhibition of TLR9—the primary sensor of bacterial DNA—significantly reduced the DNA-induced adipogenic response, demonstrating that adipocyte modulation is at least in part mediated through TLR9 signaling. In summary, B. abortus promotes MSC differentiation toward an inflammatory adipocyte phenotype. It involves a TLR-9-mediated DNA detection. It may contribute to osteoarticular injury and infection-associated bone resorption. Full article

Titanium and its alloys are used in dental and orthopedic implants. However, long-term stability remains a clinical challenge. To overcome this limitation, surface modification has been investigated to improve surface properties. Our previous study demonstrated that the immobilization of secretory leukocyte protease inhibitor (SLPI) on the titanium surface promotes osteoblast adhesion, proliferation, and differentiation in vitro. The current study demonstrated the first in vivo evaluation of SLPI as a bioactive coating for medical implants. Grade 5 titanium screws were coated with 10 µg/mL of recombinant human SLPI (rhSLPI) for 24 h via simple physical adsorption, and the results were preliminarily validated via FE-SEM and ELISA. These SLPI-coated titanium screws (TiSs) were then placed in the tibia of Sprague–Dawley rats for 4 and 8 weeks. The hematological and biochemical parameters (BUN, Creatinine, AST, and Troponin I) demonstrated no acute systemic alterations within the 8-week period across all groups. Moreover, micro-computed tomography (micro-CT) and histological analysis revealed significantly higher bone volume fraction (%BV/TV) at 4 weeks compared to uncoated controls (20.64% ± 2.452% vs. 11.73% ± 0.524%). Finally, the biomechanical stability of implants, assessed using the removal torque test, showed that TiSs showed higher strength compared to Ti at both 4 and 8 weeks. In conclusion, this study represents a novel approach to transitioning rhSLPI-coated titanium evaluation from in vitro models to an in vivo rat model. rhSLPI surface functionalization enhances early-stage osseointegration and improves implant mechanical stability without acute hematological and biochemical alterations. These proof-of-concept findings suggest the potential of SLPI as a bioactive coating strategy. Full article

Bone regeneration requires tight coordination between mesenchymal stem cells (MSCs), immune signaling, and extracellular matrix remodeling. Yet, how atypical immune receptors contribute to this process remains unclear. Here, we identify Toll-like receptor 10 (TLR10) as a key regulator of osteogenic differentiation in human adipose-derived MSCs. Herein, ASC/TERT1 MSCs were engineered to overexpress or silence TLR10 using lentiviral vectors, and osteogenic differentiation (0–14 days) was assessed by metabolic assays—RT-qPCR of COL1A2, ALPL and BGLAP—Alizarin Red S staining, and quantitative mass spectrometry. Enhancing TLR10 expression promoted osteogenic gene programs, extracellular matrix organization, metabolic adaptation, and robust matrix mineralization, whereas TLR10 suppression maintained proliferative states and impaired osteoblast maturation. Proteomic analyses revealed that TLR10 selectively activates osteogenic, ECM-remodeling, and vitamin D-responsive pathways, while restraining programs antagonistic to differentiation. Notably, active vitamin D induced TLR10 expression and partially restored osteogenesis in TLR10-deficient cells, indicating that TLR10 is associated with vitamin D-driven bone formation. Together, beyond its established role in innate immunity, TLR10 emerges as a vitamin D-responsive regulator of mesenchymal stem cell osteogenesis, highlighting a potential therapeutic axis to enhance bone regeneration and osteogenic outcomes. Full article

This study investigates the mechanical and biological properties of diamond lattice structure produced through lithography-based ceramic manufacturing, an additive manufacturing technique. HA480 specimens, cubes of 5 × 5 × 5 mm, were manufactured with appropriate pore sizes and porosity. Printed HA480 specimens were tested and analysed for compression strength, cell proliferation, and cell attachment. The printed cubes displayed interconnected pore geometry. A set of ten HA480 diamond lattice structure specimens were compressed until failure to obtain a compressive strength of 10.7 MPa. HA480 solid scaffolds were seeded with the human osteoblast cell line hFOB 1.19 cells. The fluorescence level results were higher on day 3 and decreased on days 5 and 7. Cell attachment was observed from day 1 to day 7. In this study, biodegradation was also evaluated with diamond lattice structure immersed in the simulated body fluid for days 1 and 7 and 28 days. The Scanning Electron Microscopy showed precipitation after 7 days immersion and evidence of apatite after 28 days on the HA480 surface. The findings provide evidence that HA480 reacts with biological fluids and can be used as a material for bone regeneration scaffold. Full article

This study compared the wound-healing response and osteogenic gene expression profile of osteoblasts exposed to pediatric-equivalent concentrations of dexmedetomidine (DXMT) and propofol (POF). Human osteoblast-like SAOS-2 cells were assigned to control, low- and high-dose DXMT and POF groups based on pharmacokinetically derived free-drug levels. Scratch-wound closure was quantified over 24 h, and expression of osteogenesis- and cytoskeleton-related genes (RANKL, RUNX2, SP7, BMP2, VIM, VCL, OCN, ALP) was measured by SYBR Green quantitative Polymerase Chain Reaction (qPCR). Normality was assessed using the Shapiro–Wilk test, and group differences were analyzed with two-way ANOVA followed by Tukey’s multiple comparisons test (p < 0.05). All groups demonstrated complete scratch closure by 24 h, with no differences at 6 h. At 18 h, POF did not differ from the control, whereas DXMT significantly accelerated closure at both doses in a dose-dependent fashion. High-dose DXMT significantly increased VIM (3.95 ± 3.12, p = 0.0144) and BMP2 (2.28 ± 0.70, p = 0.0002) expression, while RUNX2, SP7, and RANKL remained comparable to controls. ALP (1.68 ± 0.40, p = 0.0005) and OCN (3.31 ± 0.35, p = 0.0108) were significantly elevated only in the high-dose DXMT group, whereas POF showed no significant effects. At clinically relevant concentrations, DXMT was associated with enhanced scratch closure and increased expression of selected osteogenesis- and cytoskeleton-related genes in SAOS-2 cells, whereas POF showed limited effects under the tested conditions. These findings suggest that DXMT may influence early in vitro cellular responses relevant to bone healing and should be further validated in functional differentiation models and in vivo studies. Full article

In a previous study, we demonstrated that a novel surface treatment applied to laser-melted Ti6Al4V substrates supports osteoblast-like cell adhesion, proliferation, and the activation of early osteogenic pathways. Building on these preliminary findings, the present work aimed to further investigate the ability of the same surface to promote extracellular matrix (ECM) deposition, organization, and osteogenic maturation, which are critical events for the establishment of a stable bone–implant interface in subperiosteal dental implants. Human osteoblast-like MG-63 cells were cultured on Ti6Al4V discs subjected to different surface treatments, including a proprietary surface modification (ATcs) specifically designed for subperiosteal applications. ECM formation and maturation were evaluated through scanning electron microscopy coupled with energy-dispersive spectroscopy, immunofluorescence, and semiquantitative analyses of osteogenic markers type I collagen (COL1A1), secreted protein acidic and rich in cysteine (SPARC), and dentin matrix protein 1 (DMP1) through Western blotting. The results showed that, while all tested surfaces supported cell adhesion, the ATcs surface promoted a distinct osteogenic profile characterized by enhanced DMP1 expression, organized collagen deposition, and the formation of calcium–phosphate–rich mineralized structures. Compared to surfaces that primarily stimulated cell proliferation or early matrix production, ATcs appeared to favour progression toward late-stage osteogenic maturation and matrix mineralization. Taken together, these findings extend our previous observations and indicate that this novel surface treatment not only supports osteoblast viability and early differentiation but also promotes extracellular matrix maturation, a key prerequisite for effective osseointegration. Although further in vivo studies are required, the present data provide additional biological rationale for the use of ATcs-treated Ti6Al4V surfaces in next-generation custom-made subperiosteal implant designs. Full article

Repairing maxillofacial bone defects remains a major clinical challenge due to inadequate vascularisation and poor integration with host tissue. While bioactive scaffolds have shown promise in supporting osteogenesis and angiogenesis, achieving robust and synchronised dual regenerative outcomes is still elusive. This study presents a multifunctional, cell-free magnetic hydrogel platform designed to biomimetically coordinate osteogenic and angiogenic processes for effective maxillofacial bone regeneration. The composite poly(vinyl alcohol)-vaterite (PVA-Vat) hydrogel scaffold incorporates tuneable magnetic nanoparticles (MNPs) composed of single-domain superparamagnetic iron oxide (Fe₃O₄). By harnessing magneto-mechanical cues to orchestrate bilateral communication between human bone mesenchymal stem cells and endothelial cells, this platform provides a deeper mechanistic understanding of coupled tissue regeneration and delivers superior dual-regenerative performance for maxillofacial bone repair. Under magnetic stimulation, a coculture system demonstrated strong osteogenesis-angiogenesis coupling mediated by reciprocal VEGFA-BMP2 signalling. This reciprocal crosstalk was evidenced by a synergistic amplification of VEGFA and BMP2 expression in coculture compared to monocultures, where MNP-stimulated osteoprogenitors secreted VEGFA to drive endothelial capillary-like network formation, while endothelial cells reciprocally enhanced endogenous BMP2 levels to accelerate osteoblastic mineralisation. These findings establish MNP-integrated hydrogels as a cell-free, multifunctional platform capable of synchronising dual regenerative pathways, offering a biomimetic strategy to overcome vascularisation and integration barriers in maxillofacial bone repair. Full article

Bone formation requires a substantial energy supply to sustain extracellular matrix production and mineralization, yet the temporal contribution of lipid metabolism during osteoblast maturation remains incompletely characterized. This study investigated the molecular and transcriptional remodeling of lipid metabolism. Intracellular lipid distribution was analyzed by confocal microscopy using Nile Red staining. Transcriptional modulation of lipid synthesis, storage, lipolysis, genes associated with mitochondrial fatty acid oxidation, and osteogenic markers were assessed by quantitative real-time PCR, and the biochemical composition was evaluated by Raman spectroscopy. Early stages of spheroid development showed higher expression of genes involved in lipid synthesis and storage (FASN, DGAT2, and PLIN2) together with intracellular lipid accumulation, whereas later stages displayed increased expression of lipolytic and β-oxidation markers (PNPLA2/ATGL, CPT1A, and HADHA), accompanied by the redistribution of lipid droplets. The Raman analysis revealed a time-dependent variation of lipid-associated CH₂/CH₃ bands and modulation of protein-related Amide I–III signals, consistent with biochemical remodeling during maturation. Overall, the data indicate a coordinated transcriptional shift from lipid accumulation-associated pathways toward lipid mobilization during osteogenic progression in a 3D culture. This model provides a controlled experimental platform for investigating metabolic regulation during bone formation and for studying metabolic alterations associated with skeletal disorders. Full article

Boron carbide (B₄C)-reinforced metal matrix composites (MMCs) are promising candidates for biomedical implants due to their mechanical properties and potential biological compatibility. In this study, in vitro biocompatibility and cytotoxicity of B₄C-reinforced CoCrMo, Ti, and 17-4 PH alloys were systematically evaluated using human osteoblast (HOB) cells. Composites were fabricated via powder metallurgy with varying B₄C reinforcement ratios (CoCrMo and Ti: 5–10 wt%; 17-4 PH: 3–12 wt%). Extracts prepared according to ISO 10993-12 standards were applied at different concentrations (100%, 50%, 25%, 12.5%) to assess cell viability using the MTT assay over 24, 48, and 72 h. Results demonstrated a clear dose-dependent cytotoxic effect across all composite systems. Ti composites exhibited the highest biocompatibility, with cell viability largely preserved even at higher B₄C ratios. CoCrMo composites showed moderate cytotoxicity, which decreased upon extract dilution, indicating low-concentration compatibility. In contrast, 17-4 PH composites revealed significant cytotoxicity at higher extract concentrations, exacerbated by increasing B₄C content. Literature-supported findings confirm that B₄C incorporation enhances hardness, wear resistance, and elastic modulus, yet excessive reinforcement can induce local stress and particle detachment, affecting cellular tolerance. Diluted extracts of Ti and CoCrMo composites maintained cell viability at a biocompatible level consistent with ISO 10993-5 criteria. These results highlight the promising biocompatibility of B₄C-reinforced Ti and CoCrMo alloys for biomedical applications and provide a biological basis for the design of next-generation composite implants. Full article

Objectives: In dental implantology, the priorities in scientific research are to identify solutions that guarantee a beneficial biomaterial–tissue interaction, both in terms of implant biointegration and protection against infections. The experimental approach consisted of chemical deposition of silver (Ag), silver and hydroxyapatite (HAP) on a TiZr metallic support. The aim of the research is to study the influence of hydroxyapatite on the possible adverse effects produced by silver in antibacterial coatings. Methods: The characterization of the coating was performed by scanning electron microscopy (SEM) and EDS spectroscopy, XRD diffraction and FT-IR infrared analysis. In vitro cell viability and adhesion testing was performed by quantitative (MTT) and qualitative fluorescence-based assays on samples (without deposition and with chemical deposition), in the presence of human fetal osteoblasts (hFOB cell line) after 8 days of incubation. Results: The findings of the study indicate an increase in cell viability by combining silver with hydroxyapatite. Preliminary data indicated a cell viability of 20% when the metal support is coated exclusively with silver and 60% in the presence of hydroxyapatite in the silver coating. Conclusions: The experimental study offers insights into the potential cytotoxic effects of silver in antibacterial coatings. Co-deposition with hydroxyapatite improved osteoblast viability compared to surfaces coated with silver alone, indicating that it may have a beneficial effect in Ag-based surface functionalization. The underlying mechanism (e.g., modulation of silver species/ion release) was not directly quantified in this work and should be addressed in future studies. Full article

Postmenopausal osteoporosis is an age-related condition in which estrogen deficiency drives low-grade inflammation and oxidative stress, disrupting the homeostatic balance between bone formation and resorption. Since osteopenia represents a critical intermediate stage, preventive strategies are essential to mitigate its progression. Preclinical studies suggest that hydrogen sulfide (H₂S), a gaseous mediator with antioxidant properties, protects bone metabolism by supporting osteoblast function and suppressing osteoclast activity. Building on this evidence, we conducted the first exploratory clinical trial assessing the effects of inhalation therapy with sulfurous mineral waters on systemic biomarkers in postmenopausal women with osteopenia. Thirty-eight eligible participants underwent a daily inhalation of sulfurous waters (14.6 mg/L sulfide) for 12 consecutive days. Biomarkers of oxidative stress, inflammation, and bone turnover were assessed at baseline, immediately post-treatment, and five days after cessation in the serum of patients. The treatment was well tolerated and did not cause any early adverse effect. Serum H₂S levels, measured in a subset of participants, significantly increased, confirming systemic bioavailability. Sulfurous water inhalation induced a marked change in oxidative stress, with malondialdehyde levels declining by up to 37% from baseline. Pro-inflammatory cytokines, particularly IL-8 and MIP-1α, were significantly decreased (up to 50–70%) at the end of the treatment. Reference bone turnover markers P1NP and CTX-1 did not show significant changes; however, BALP exhibited a significant increase, suggesting the activation of pathways linked to biomineralization. These findings provide preliminary human evidence that inhaled sulfurous waters enhance systemic H₂S bioavailability and modulate redox and inflammatory pathways associated with bone remodeling in osteopenic women, supporting the rationale for further controlled pharmacodynamic investigations evaluating the potential of H₂S in bone health. Full article

FAM3A, FAM3B, FAM3C and FAM3D are members of the “family with sequence similarity 3” (FAM3) gene family, an emerging class of cytokine-like proteins with a unique structural globular β-β-α fold and distinct biological functions. With widespread expression in tissue, organs and in many cell types, their specific roles in human diseases have been the focus of much research. FAM3A acts as a positive regulator of metabolic health, typically activating canonical pro-survival and metabolic pathways. FAM3B, also called PANDER (PANcreatic DERived Factor), exerts critical physiological functions in the regulation of glycemic levels via promotion of hepatic glucose production and pancreatic β-cell insulin secretion. FAM3C, also named ILEI (Interleukin-like EMT inducer), is involved as an inducer of epithelial–mesenchymal transition (EMT) and cancer metastasis, as well as osteoblast differentiation and bone mineralization. FAM3D is a gut-secreted protein and potential regulator of gastrointestinal homeostasis and microbiota-induced inflammation. Here we provide an overview of previous studies supporting that FAM3 proteins act through putative membrane receptors and co-partners, including fibroblast growth factor receptor (FGFR), leukemia inhibitory factor receptor (LIFR), formyl peptide receptor (FPR1/2), to activate diverse downstream signaling pathways on different cellular contexts. Basic and clinical studies suggest that the FAM3 family influences both obesity, diabetes, and other metabolic disorders; thus, its expression may have diagnostic potential. The differential and often cancer-specific expression patterns make members of the FAM3 family promising candidates for biomarkers and therapeutic targets of some types of neoplasia. Full article

The vitamin D receptor (VDR) acts as both a nuclear transcription factor and a non-genomic mediator that regulates a broad spectrum of physiological processes beyond calcium and phosphate homeostasis. VDR plays an important role in the modulation of ion channels across multiple tissues, including osteoblasts, renal and intestinal epithelial cells, neurons, and vascular smooth muscle. These regulatory mechanisms encompass genomic actions through vitamin D response elements in target genes—such as TRPV5, TRPV6, KCNK3, and KCNH1—as well as rapid, non-genomic actions at the plasma membrane involving protein disulfide isomerase A3 and associated signaling cascades. VDR-mediated transcriptional control of calcium, potassium, and chloride channels contributes to the fine-tuning of cellular excitability, calcium transport, and mitochondrial function. Evidence also implicates VDR–ion channel crosstalk in various pathological contexts, including renal cell carcinoma, breast and cervical cancers, pulmonary arterial hypertension, and osteoporosis. Understanding the molecular interplay between VDR and ion channels provides new perspectives on the pleiotropic effects of vitamin D and offers promising therapeutic opportunities in oncology, cardiovascular disease, and skeletal disorders. This review synthesizes previous and current evidence on the genomic and non-genomic mechanisms underlying VDR–ion channel regulation and highlights novel frontiers in vitamin D signaling relevant to human health and disease. Full article

Quercetin (QE) is a widely distributed dietary flavonol with antioxidant and anti-inflammatory properties that has attracted interest as a modulator of bone remodeling and osteoporosis-related bone loss. In vitro data on osteoblasts, osteoclasts, and mesenchymal stem cells indicate that QE attenuates oxidative stress, suppresses pro-inflammatory signaling, and promotes osteogenic differentiation through modulation of pathways such as Nrf2/ARE, NF-κB, Wnt/β-catenin, and ER stress-related cascades. In vivo findings from animal models of estrogen deficiency, diabetes, and glucocorticoid-induced osteoporosis demonstrate that QE improves bone mineral density, trabecular microarchitecture, and biomechanical strength while reducing osteoclast number and activity, thereby attenuating osteoporotic bone deterioration. Collectively, preclinical evidence positions QE as a pleiotropic agent promoting osteoblastogenesis, inhibiting osteoclastogenesis, and balancing redox/inflammatory homeostasis in bone, despite bioavailability challenges. Future research should prioritize clinical trials with optimized formulations (e.g., nanoparticles) to validate efficacy, safety, and fracture outcomes in humans. The present review critically evaluates the chemical characteristics, pharmacokinetics, safety profile, and bone-targeted biological activity of QE, emphasizing effects on bone cells and skeletal metabolism. Full article

Glycogen synthase kinase-3 (GSK3) inhibition is a commonly used approach to promote osteogenic differentiation through activation of Wnt signaling. However, 6-bromoindirubin-3′-oxime (BIO), which is commonly used for GSK3 inhibition, also targets JAK/STAT, raising the possibility of dual pathway interference during osteoblast differentiation, as both GSK3 and JAK/STAT pathways are critical regulators of osteoblastogenesis. In this study, we investigated the effect of BIO on the osteoblast differentiation of hMSCs-TERT4. While BIO had no significant effect on cell viability or apoptosis, it markedly inhibited osteoblast differentiation, as evidenced by reduced ALP activity, decreased matrix mineralization, and downregulation of osteoblast-associated markers. Microarray analysis followed by qRT-PCR validation revealed downregulation of Wnt and TGF-β pathway genes. These findings show that BIO suppresses osteoblast commitment and osteogenic differentiation, accompanied by altered Wnt- and TGF-β-related gene expression. This study provides mechanistic insight into the off-target consequences of widely used small molecules and highlights the importance of dissecting pathway-specific roles in stem cell differentiation. Understanding the interplay between GSK3 and JAK signaling is essential for optimizing pharmacological strategies in skeletal regenerative medicine. This study highlights the importance of pathway selectivity when using small molecules in stem cell-based therapies for bone regeneration. Full article