Search Results (912)

Objectives: To prepare porous scaffolds combining hydrogel and hydroxycarbonateapatite, enriched with a promising therapeutic agent, gold nanoparticles, to improve bone regeneration. The fabrication procedure is conducted under mild conditions, without toxic or aggressive chemicals, at physiological pH, and low temperatures; Methods: Gold nanoparticles (15–20 nm), were obtained by the Turkevith method. The scaffolds were fabricated by the GELPOR3D method, which has demonstrated its ability to integrate thermal labile molecules, during the scaffold fabrication process. The role of these nanoparticles in promoting cell adhesion, proliferation, and mineralization processes in vitro has been studied using osteoprogenitor MC3T3-E1 cells; Results: The scaffold fabrication conditions, combined with the surface functionalization of the gold nanoparticles with poly(ethylene glycol), ensure their uniform distribution throughout the scaffold and facilitate their gradual release over 48 h in a physiological medium. A significant increase in the mean cell area and a significant decrease in the circularity index during the early stages of osteoblast differentiation are observed. These pieces of evidence suggest that adequate cell spreading could lead to enhanced proliferation and matrix deposition activity; Conclusions: Scaffolds containing these gold nanoparticles exhibited a marked improvement in adhesion, proliferation, and mineralization of preosteoblasts (MC3T3 cells) at the concentrations studied. The functionalization of the nanoparticles, along with the shaping procedure employed, is critical for their homogeneous dispersion throughout the scaffold and their progressive release. The findings confirm the crucial role of gold nanoparticles in the early stages of osteoblast differentiation, which is essential for the transition from premature osteoblasts to mature osteoblasts. Full article

Background/Objectives: Herein, we investigated the effect of platelet-rich fibrin (PRF) treatment combined with no-ozone cold plasma (NCP) on growth factor levels, rat bone-marrow stem cell (rBMSC) proliferation, and alkaline phosphatase (ALP) activity in the early stage of differentiation into osteoblasts. Methods: The PRF used in the experiment was prepared by collecting blood from the jugular vein of rats, followed by centrifugation. The obtained PRF was treated with NCP, and the cell culture media were conditioned with the PRF extracts alone or with NCP-treated PRF extracts. Three different experimental groups were defined: no treatment (NT); cell culture media extracted from PRF (PRF); and cell culture media extracted from PRF treated with NCP (PRF + NCP). Enzyme-linked immunosorbent assays were performed to determine the levels of transforming growth factor (TGF)-β and platelet-derived growth factor (PDGF) AB. Water-soluble Tetrazolium-1 assay was performed to measure cell proliferation in rBMSCs. To analyze cell differentiation into osteoblasts, ALP staining and real-time PCR were performed. Results: Growth factor levels increased in response to treatment (TGF-β: p < 0.001, PDGF AB: p < 0.05), and the cell proliferation rate increased with treatment (145.29% and 150.05% for PRF and the PRF + NCP groups, respectively, relative to the NT group, p < 0.001). Evaluation of the ALP staining intensity and mRNA expression levels showed that the ALP activity was highest in the PRF + NCP group (p < 0.001). Conclusions: Our results confirmed that NCP treatment enhanced the release of several different growth factors contained in PRF to the culture media and that treatment with PRF and NCP increased the proliferation of rBMSCs and their differentiation into osteoblasts. Full article

Background: A trilayered collagen/collagen–magnesium–hydroxyapatite (Col/Col-Mg-HA) scaffold is used in clinical practice to treat osteochondral lesions, but the regeneration of the subchondral bone is still not satisfactory. Objective: The aim of this study was to test, in vitro, the osteoinductivity induced by the addition of bone morphogenetic protein-2 (BMP-2) or amorphous calcium phosphate granules with strontium ions (Sr-ACP), in order to improve the clinical regeneration of subchondral bone, still incomplete. Methodology: Normal human osteoblasts (NHOsts) were seeded on the scaffolds and grown for 14 days in the presence of human osteoclasts and conditioned medium of human endothelial cells. NHOst adhesion and morphology were observed with transmission electron microscopy, and metabolic activity was tested by Alamar blue assay. The expression of osteoblast- and osteoclast-typical markers was evaluated by RT-PCR on scaffolds modified by enrichment with BPM-2 or Sr-ACP, as well as on unmodified material used as a control. Results: NHOsts adhered well to all types of scaffolds, maintained their typical morphology, and secreted abundant extracellular matrix. On the modified materials, COL1A1, SPARC, SPP1, and BGLAP were more expressed than on the unmodified ones, showing the highest expression in the presence of BMP-2. On Sr-ACP-enriched scaffolds, NHOsts had a lower proliferation rate and a lower expression of RUNX2, SP7, and ALPL compared to the other materials. The modified scaffolds, particularly the one containing Sr-ACP, increased the expression of the osteoclasts’ typical markers and decreased the OPG/RANKL ratio. Both types of scaffold modification were able to increase the osteoinductivity with respect to the original scaffold used in clinical practice. BMP-2 modification seemed to be more slightly oriented to sustain NHOst activity, and Sr-ACP seemed to be more slightly oriented to sustain the osteoclast activity. These could provide a concerted action toward better regeneration of the entire osteochondral unit. Full article

The aim of this work was to produce bone scaffolds containing whey protein isolate and pearl powder and to conduct a preliminary assessment of the biomedical potential in vitro and in vivo. This included analysis of structural, physicochemical, mechanical, and biological properties, which revealed that biomaterials containing pearl powder exhibited an enhanced porous structure, increasing absorptive properties, and decreasing proteolytic capacity with increasing inorganic component content. Pearl powder content in the biomaterials did not clearly influence their mechanical properties or their ability to release calcium ions, as well as proteins. Extracts obtained from all tested biomaterials showed no cytotoxicity in vitro. The surfaces of all biomaterials promoted normal human osteoblast growth, proliferation, and osteogenic differentiation. Furthermore, all biomaterials did not display toxicity in vivo, but no changes in Danio rerio were observed after evaluation of the biomaterial containing the highest amount of pearl powder–10% v/w (marked as WPI/P10). Taking all the obtained results into account, it appears that this biomaterial can be promising for bone scaffolds and similar applications, thanks to its porous structure, high cytocompatibility in vitro, and lack of toxicity in vivo. However, advanced studies will be conducted in the future. Full article

Proinflammatory cytokines such as IL-1β, IL-6, and TNF-α are key mediators of inflammatory bone loss and are commonly described as inhibitors of osteoblast function. However, their effects on osteogenesis remain controversial, likely due to the differences in the cell models and experimental settings in in vitro studies. We recently showed that these cytokines significantly enhanced the mineralization of primary human osteoblast-like cells (OBs). Here, we provide the first analysis of cytokine effects on the osteogenesis of the widely used human osteoblastic cell line hFOB 1.19 and compare them to primary OBs. Unexpectedly, all three cytokines significantly inhibited mineralization in hFOB 1.19 cells without affecting the proliferation. IL-1β and TNF-α also suppressed ALP activity, whereas IL-6 acted ALP-independent but increased the osteogenic marker expression despite the reduced mineralization, indicating a possible uncoupled differentiation and mineralization. Morphological and transcriptional analyses indicated that hFOB 1.19 cells represent an earlier osteogenic differentiation stage, while primary OBs show phenotypic heterogeneity and donor-dependent expression profiles. These data demonstrate that proinflammatory cytokines can have severely different effects on the osteogenesis of different cell models, supported by the highly contradictory findings reported in the literature. Nevertheless, elucidating the mechanisms underlying the inhibition of osteogenesis in hFOB 1.19 cells may provide important insights into the cell model and differentiation-stage-specific cytokine effects. Full article

Cadmium (Cd), a pervasive environmental and industrial toxicant, bioaccumulates and exerts severe detrimental effects on skeletal integrity across diverse animal species. Cd-induced bone injury manifests as osteoporosis, osteomalacia, and increased fracture risk, posing significant health and welfare concerns for wildlife and livestock inhabiting contaminated ecosystems. The pathogenesis hinges critically on the disruption of bone remodeling, a tightly regulated process orchestrated by osteoclasts (OCs) responsible for bone resorption and osteoblasts (OBs) responsible for bone formation. This comprehensive review synthesizes the latest mechanistic insights into how Cd disturbs OC and OB function and their intricate crosstalk, leading to net bone loss. Cd directly impairs OB proliferation, differentiation, and mineralization capacity through multiple pathways, including the inhibition of Wnt/β-catenin signaling, induction of oxidative stress and mitochondrial dysfunction, promotion of apoptosis and senescence, and disruption of extracellular matrix protein synthesis. Simultaneously, Cd potently stimulates excessive OC formation and activity. It achieves this by upregulating the RANKL/OPG axis, enhancing reactive oxygen species (ROS) production which activates key OC transcription factors, modulating key signaling pathways, and promoting pro-osteoclastogenic inflammatory cytokine release from bone marrow and immune cells. Critically, Cd disrupts the vital communication between OBs and OCs, perturbing the coupling signals essential for balanced remodeling. Emerging evidence highlights roles for Cd-induced epigenetic modifications and autophagy/mitophagy flux alterations. This narrative review integrates the findings from in vivo animal models and in vitro cellular studies, providing potential therapeutic interventions and mitigation strategies for Cd-induced bone toxicity. Understanding these complex and interacting mechanisms provides a foundation for identifying potential therapeutic targets to mitigate Cd bone toxicity in animals and informs ecological risk assessment and management strategies in contaminated environments. Full article

Bone tissue engineering has gained attention recently as a method for regenerating bone critical-size defects. This work aims to synthesize a hydrogel based on gelatin, di-amine polyethylene glycol, Polyethylene Glycol-Polypropylene Glycol-Polyethylene glycol, using genipin as a cross-linker and adding hydroxyapatite as a ceramic insert that can be used as a cellular scaffold in bone tissue engineering. Characterization was performed using Fourier transform infrared spectroscopy, identifying the leading absorption bands to verify that the hydrogels cross-linked correctly. The hydrogels with elastic modules and resistances that best adapted to the values reported for the mandibular trabecular bone were identified through mechanical tests. Using scanning electron microscopy, the presence of hydroxyapatite in the hydrogels was verified. The hydrogels with the best results were selected to carry out the biological assays. The cell viability assay verified that the osteoblastic cells proliferated better in the hydroxyapatite scaffolds, and the composite hydrogel induced osteoblast differentiation from undifferentiated mesenchymal stem cells. Hydrogels loaded with hydroxyapatite proved to be a promising biomaterial with potential application in bone regeneration. Full article

Electrospun nanofibrous membranes have gained considerable attention in bone tissue engineering due to their ability to mimic the extracellular matrix and provide a suitable environment for cell attachment and proliferation. This study investigates the fabrication, characterization, and biocompatibility of poly(L-lactic acid) (PLA)-based membranes enhanced with periclase (MgO) and gold nanoparticles (AuNPs). The membranes were fabricated using an optimized electrospinning process and subsequently characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FT-IR), and contact angle measurements. Additionally, in vitro biodegradation studies in simulated body fluid (SBF) and cytocompatibility tests with osteoblast-like cells were conducted. The results demonstrated that the incorporation of MgO and AuNPs significantly influenced the structural and chemical properties of the membranes, improving their wettability and bioactivity. SEM imaging confirmed uniform fiber morphology with well-distributed nanoparticles. FT-IR spectroscopy indicated successful integration of bioactive components into the PLA matrix. Cytocompatibility assays showed that modified membranes promoted higher osteoblast adhesion and proliferation compared to pristine PLA membranes. Furthermore, biodegradation studies revealed a controlled degradation rate suitable for guided bone regeneration applications. These findings suggest that electrospun PLA membranes enriched with MgO and AuNPs present a promising biomaterial for GBR applications, offering improved bioactivity, mechanical stability, and biocompatibility. Full article

A thermosensitive collagen-based gel (TSV gel), containing type I and III collagen, has been developed to improve the handling and stability of bone graft materials. However, its direct effect on osteoblasts is not well understood. This in vitro study evaluated the biological response of human oral osteoblasts to four bone substitutes: OsteoBiol^® GTO^® (larger granules with 20% TSV gel), Gen-OS^® (smaller granules), Gen-OS^® combined with 50% TSV gel (Gen-OS^®+TSV), and TSV gel alone. Cell proliferation, adhesion, morphology, collagen and calcium deposition, alkaline phosphatase (ALP) activity, gene expression of osteogenic markers and integrins, and changes in pH and extracellular calcium and phosphate levels were investigated. All materials supported osteoblast activity, but Gen-OS+TSV and GTO showed the most pronounced effects. These two groups promoted better cell adhesion and proliferation, higher ALP activity, and greater matrix mineralization. GTO improved cell adhesion, while the addition of TSV gel to Gen-OS enhanced biological responses compared with Gen-OS alone. Integrins α2, α5, β1, and β3, important for cell attachment to collagen, were notably upregulated in Gen-OS+TSV and GTO. Both groups also showed increased expression of osteogenic markers such as BMP-2, ALP, and osteocalcin (OCN). Higher extracellular ion concentrations and a more alkaline pH were observed, particularly in conditions without cells, suggesting active ion uptake by osteoblasts. In conclusion, combining TSV gel with collagen-based granules improves the cellular environment for osteoblast activity and may support bone regeneration more effectively than using either component alone. Full article

Bone integrity is maintained through continuous remodeling, orchestrated by the coordinated actions of osteocytes, osteoblasts, and osteoclasts. Once considered passive bystanders, osteocytes are now recognized as central regulators of this process, mediating biochemical signaling and mechanotransduction. Malfunctioning osteocytes contribute to serious skeletal disorders such as osteoporosis. Mesenchymal stromal cells (MSCs), multipotent stem cells capable of differentiating into osteoblasts, have emerged as promising agents for bone regeneration, primarily through the paracrine effects of their secreted exosomes. MSC-derived exosomes are nanoscale vesicles enriched with proteins, lipids, and nucleic acids that promote intercellular communication, osteoblast proliferation and differentiation, and angiogenesis. Notably, they deliver osteoinductive microRNAs (miRNAs) that influence osteogenic markers and support bone tissue repair. In vivo investigations validate their capacity to enhance bone regeneration, increase bone volume, and improve biomechanical strength. Additionally, MSC-derived exosomes regulate the immune response, creating pro-osteogenic and pro-angiogenic factors, boosting their therapeutic efficacy. Due to their cell-free characteristics, MSC-derived exosomes offer benefits such as diminished immunogenicity and minimal risk of off-target effects. These properties position them as promising and innovative approaches for bone regeneration, integrating immunomodulatory effects with tissue-specific regenerative capabilities. Full article

Proper joint function has a significant impact on people’s quality of life. Joints are the point of connection between two or more bones and consist of at least three elements: joint surfaces, the joint capsule, and the joint cavity. Joint diseases are a serious social problem. Risk factors for the development of these diseases include overweight and obesity, gender, and intestinal microbiome disorders. Another factor that is considered to influence joint diseases is trace elements. Under normal conditions, elements such as iron (Fe), copper (Cu), cobalt (Co), iodine (I), manganese (Mn), zinc (Zn), silver (Ag), cadmium (Cd), mercury (Hg), lead (Pb), nickel (Ni) selenium (Se), boron (B), and silicon (Si) are part of enzymes involved in reactions that determine the proper functioning of cells, regulate redox metabolism, and determine the maturation of cells that build joint components. However, when the normal concentration of the above-mentioned elements is disturbed and toxic elements are present, dangerous joint diseases can develop. In this article, we focus on the role of trace elements in joint function. We describe the molecular mechanisms that explain their interaction with chondrocytes, osteocytes, osteoblasts, osteoclasts, and synoviocytes, as well as their proliferation, apoptosis, and extracellular matrix synthesis. We also focus on the role of these trace elements in the pathogenesis of joint diseases: rheumatoid arthritis (RA), osteoarthritis (OA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), and systemic lupus erythematosus (SLE). We describe the roles of increased or decreased concentrations of individual elements in the pathogenesis and development of joint diseases and their impact on inflammation and disease progression, referring to molecular mechanisms. We also discuss their potential application in the treatment of joint diseases. Full article

Bioactive glass materials have been used for decades in orthopedic surgery, traumatology, and oral and maxillofacial surgery to repair bone defects. This study aimed to evaluate in vitro the survival and proliferation of MG63 human osteosarcoma-derived cells on S53P4 bioactive glass (BonAlive^® granules). Microscopic visualization was performed to directly observe the interactions between the cells and the material. Osteoblast-like cells were examined on non-adherent test plates, on tissue culture (TC)-treated plates and on the surface of the bioglass to assess the differences. Cell survival and proliferation were monitored using a CCK-8 optical density assay. Comparing the mean OD of MG63 cells in MEM on TC-treated plates with cells on BG, we detected a significant difference (p < 0.05), over each time of observation. The sustained cell proliferation confirmed the non-cytotoxic property of the bioglass, as the cell number increased continuously at 48, 72, 96, and 168 h and even did not plateau after 168 h. Since the properties of bioglasses can vary significantly depending on their composition and environment, a thorough characterization of their biocompatibility is crucial to ensure their effective and appropriate application—for example, during hip and knee prosthesis insertion. Full article

Three-dimensional cell culture systems are relevant in vitro models for studying cellular behavior. In this regard, this present study investigates the interaction between human osteoblast-like cells and 3D-printed scaffolds mimicking physiological and osteoporotic bone structures under simulated microgravity conditions. The objective is to assess the effects of scaffold architecture and dynamic culture conditions on cell adhesion, proliferation, and metabolic activity, with implications for osteoporosis research. Polylactic acid scaffolds with physiological (P) and osteoporotic-like (O) trabecular architectures were 3D-printed by means of fused deposition modeling technology. Morphometric characterization was performed using micro-computed tomography. Human osteoblast-like SAOS-2 and U2OS cells were cultured on the scaffolds under static and dynamic simulated microgravity conditions using a rotary cell culture system (RCCS). Scaffold biocompatibility, cell viability, adhesion, and metabolic activity were evaluated through Bromodeoxyuridine incorporation assays, a water-soluble tetrazolium salt assay, and an enzyme-linked immunosorbent assay of tumor necrosis factor-α secretion. Both scaffold models supported osteoblast-like cell adhesion and growth, with an approximately threefold increase in colonization observed on the high-porosity O scaffolds under dynamic conditions. The dynamic environment facilitated increased surface interaction, amplifying the effects of scaffold architecture on cell behavior. Overall, sustained cell growth and metabolic activity, together with the absence of detectable inflammatory responses, confirmed the biocompatibility of the system. Scaffold microstructure and dynamic culture conditions significantly influence osteoblast-like cell behavior. The combination of 3D-printed scaffolds and a RCCS bioreactor provides a promising platform for studying bone remodeling in osteoporosis and microgravity-induced bone loss. These findings may contribute to the development of advanced in vitro models for biomedical research and potential countermeasures for bone degeneration. Full article

Background: Potent androgen receptor pathway inhibitors induce small cell neuroendocrine prostate cancer (SCNC), a highly aggressive subtype of metastatic androgen deprivation-resistant prostate cancer (ARPC) with limited treatment options and poor survival rates. Patients with metastases in the liver have a poor prognosis relative to those with bone metastases alone. The mechanisms that underlie the different behavior of ARPC in bone vs. liver may involve factors intrinsic to the tumor cell, tumor microenvironment, and/or systemic factors, and identifying these factors is critical to improved diagnosis and treatment of SCNC. Metabolic reprogramming is a fundamental strategy of tumor cells to colonize and proliferate in microenvironments distinct from the primary site. Understanding the metabolic plasticity of cancer cells may reveal novel approaches to imaging and treating metastases more effectively. Methods: Using magnetic resonance (MR) imaging and spectroscopy, we interrogated the physiological and metabolic characteristics of SCNC patient-derived xenografts (PDXs) propagated in the bone and liver, and used correlative biochemical, immunohistochemical, and transcriptomic measures to understand the biological underpinnings of the observed imaging metrics. Results: We found that the influence of the microenvironment on physiologic measures using MRI was variable among PDXs. However, the MR measure of glycolytic capacity in the liver using hyperpolarized ¹³C pyruvic acid recapitulated the enzyme activity (lactate dehydrogenase), cofactor (nicotinamide adenine dinucleotide), and stable isotope measures of fractional enrichment of lactate. While in the bone, the congruence of the glycolytic components was lost and potentially weighted by the interaction of cancer cells with osteoclasts/osteoblasts. Conclusion: While there was little impact of microenvironmental factors on metabolism, the physiological measures (cellularity and perfusion) are highly variable and necessitate the use of combined hyperpolarized ¹³C MRI and multiparametric (anatomic, diffusion-, and perfusion- weighted) ¹H MRI to better characterize pre-treatment tumor characteristics, which will be crucial to evaluate treatment response. Full article

β-catenin is a key regulator of osteoblast differentiation, proliferation, and bone homeostasis. Through its interaction with transcription factors such as TCF/LEF, Runx2, and Osx, it coordinates gene expression essential for osteogenesis. The aim of this review is to demonstrate how β-catenin signaling is modulated by various physiological and pathological factors, including mechanical loading, oxidative stress, HIV-1 gp120, fluoride, implant topography, and microRNAs. These factors influence Wnt/β-catenin signaling through different mechanisms, often exerting opposing effects on osteoblast function. By integrating these modulators, we provide a comprehensive view of the dynamic regulation of β-catenin in bone biology. Understanding this complexity may provide insight into novel therapeutic strategies targeting β-catenin in bone regeneration, metabolic bone diseases, and pathologies such as HIV-associated bone loss or osteosarcoma. Full article