Search Results (1,777)

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

Background: Mesenchymal stem cells (MSCs) are a promising tool in regenerative medicine due to their ability to secrete paracrine factors that modulate tissue repair. Extracellular vesicles (EVs) released by MSCs contain bioactive molecules (e.g., mRNAs, miRNAs, proteins) and play a key role in intercellular communication. Methods: This study compared the transcriptomic profiles (mRNA and miRNA) of equine MSCs derived from adipose tissue (AT-MSCs), bone marrow (BM-MSCs), and ovarian fibroblasts (as a differentiated control). Additionally, miRNAs present in EVs secreted by these cells were characterized using next-generation sequencing. Results: All cell types met ISCT criteria for MSCs, including CD90 expression, lack of MHC II, trilineage differentiation, and adherence. EVs were isolated using ultracentrifugation and validated with nanoparticle tracking analysis and flow cytometry (CD63, CD81). Differential expression analysis revealed distinct mRNA and miRNA profiles across cell types and their secreted EVs, correlating with tissue origin. BM-MSCs showed unique regulation of genes linked to early development and osteogenesis. EVs contained diverse RNA species, including miRNA, mRNA, lncRNA, rRNA, and others. In total, 227 and 256 mature miRNAs were detected in BM-MSCs and AT-MSCs, respectively, including two novel miRNAs per MSC type. Fibroblasts expressed 209 mature miRNAs, including one novel miRNA also found in MSCs. Compared to fibroblasts, 60 and 92 differentially expressed miRNAs were identified in AT-MSCs and BM-MSCs, respectively. Conclusions: The results indicate that MSC tissue origin influences both transcriptomic profiles and EV miRNA content, which may help to interpret their therapeutic potential. Identifying key mRNAs and miRNAs could aid in future optimizing of MSC-based therapies in horses. Full article

Background: Mesenchymal stem cells (MSCs), multipotent and immune-regulatory cells derived from tissues such as bone marrow, dental pulp, and periodontal ligament, emerged as promising agents in regenerative dentistry. Their clinical applications include endodontic tissue regeneration, periodontal healing, and alveolar bone repair, addressing critical challenges in dental tissue restoration. Methods: A systematic review was conducted following PRISMA guidelines and registered in PROSPERO. We searched PubMed, Scopus, and Web of Science databases for open-access, English-language clinical trials and observational studies published from 2015 to 2025. Studies focusing on the application of MSCs in dental tissue regeneration were included based on predefined eligibility criteria. Results: Out of 2400 initial records, 13 studies met the inclusion criteria after screening and eligibility assessment. Most studies investigated MSCs derived from dental pulp and periodontal ligament for regenerating periodontal tissues and alveolar bone defects. The majority reported improved clinical outcomes; however, variations in MSC sources, delivery methods, sample sizes, and follow-up periods introduced methodological heterogeneity. Conclusions: MSCs show significant potential in enhancing bone and periodontal regeneration in dental practice. Nonetheless, the current evidence is limited by small sample sizes, short follow-up, and inconsistent methodologies. Future large-scale, standardized clinical trials are required to validate MSC-based regenerative therapies and optimize treatment protocols. Full article

Myocardial infarction (MI) remains one of the most common cardiovascular diseases and a leading cause of morbidity and mortality worldwide. In recent years, natural polymeric patches have attracted increasing attention as a promising therapeutic platform for myocardial tissue repair. This study explored the fabrication and evaluation of screen-printed electrodes (SPEs) on chitosan film as a novel platform for cardiac patch applications. Chitosan is a biodegradable and biocompatible natural polymer that provides an ideal substrate for SPEs, providing mechanical stability and promoting cell adhesion. Silver ink was employed to enhance electrochemical performance, and the electrodes exhibited strong adhesion and structural integrity under wet conditions. Mechanical testing and swelling ratio analysis were conducted to assess the patch’s physical robustness and aqueous stability. Silver ink was employed to enhance electrochemical performance, which was evaluated using cyclic voltammetry. In vitro, electrical stimulation through the chitosan–SPE patch significantly increased the expression of cardiac-specific genes (GATA-4, β-MHC, troponin I) in bone marrow mesenchymal stem cells (BMSCs), indicating early cardiogenic differentiation potential. In vivo, the implantation of the chitosan–SPE patch in a rat MI model demonstrated good tissue integration, preserved myocardial structure, and enhanced ventricular wall thickness, indicating that the patch has the potential to serve as a functional cardiac scaffold. These findings support the feasibility of screen-printed electrodes fabricated on chitosan film substrates as a cost-effective and scalable platform for cardiac repair, offering a foundation for future applications in cardiac tissue engineering. Full article

Xylosyltransferase-I (XT-I) plays a crucial role in skeletal development and cartilage integrity. An XT-I deficiency is linked to severe bone disorders, such as Desbuquois dysplasia type 2. While animal models have provided insights into XT-I’s role during skeletal development, its specific effects on adult bone homeostasis, particularly in human mesenchymal stem cell (hMSC) differentiation, remain unclear. This study investigates how XT-I deficiency impacts the differentiation of hMSCs into chondrocytes, osteoblasts, and adipocytes—key processes in bone formation and repair. The aim of this study was to elucidate for the first time the molecular mechanisms by which XT-I deficiency leads to impaired bone homeostasis. Using CRISPR-Cas9-mediated gene editing, we generated XYLT1 knockdown (KD) hMSCs to assess their differentiation potential. Our findings revealed significant disruption in the chondrogenic differentiation in KD hMSCs, characterized by the altered expression of regulatory factors and extracellular matrix components, suggesting premature chondrocyte hypertrophy. Despite the presence of perilipin-coated lipid droplets in the adipogenic pathway, the overall leptin mRNA and protein expression was reduced in KD hMSCs, indicating a compromised lipid metabolism. Conversely, osteogenic differentiation was largely unaffected, with KD and wild-type hMSCs exhibiting comparable mineralization processes, indicating that critical aspects of osteogenesis were preserved despite the XYLT1 deficiency. In summary, these results underscore XT-I’s pivotal role in regulating differentiation pathways within the bone marrow niche, influencing cellular functions critical for skeletal health. A deeper insight into bone biology may pave the way for the development of innovative therapeutic approaches to improve bone health and treat skeletal disorders. Full article

Osteoporosis is a multifactorial, polygenic disease characterized by reduced bone mineral density (BMD) and increased fracture risk. Genome-wide association studies (GWASs) have identified numerous loci associated with BMD and/or bone fractures, but functional characterization of these target genes is essential to understand the biological mechanisms underlying osteoporosis. This review focuses on current methodologies and key examples of successful functional studies aimed at evaluating gene function in osteoporosis research. Functional evaluation typically follows a multi-step approach. In silico analyses using omics datasets expression quantitative trait loci (eQTLs), protein quantitative trait loci (pQTLs), and DNA methylation quantitative trait loci (mQTLs) help prioritize candidate genes and predict relevant biological pathways. In vitro models, including immortalized bone-derived cell lines and primary mesenchymal stem cells (MSCs), are used to explore gene function in osteogenesis. Advanced three-dimensional culture systems provide additional physiological relevance for studying bone-related cellular processes. In situ analyses of patient-derived bone and muscle tissues offer validation in a disease-relevant context, while in vivo studies using mouse and zebrafish models enable comprehensive assessment of gene function in skeletal development and maintenance. Integration of these complementary methodologies helps translate GWAS findings into biological insights and supports the identification of novel therapeutic targets for osteoporosis. Full article

Mesenchymal stem cells have been widely investigated in the field of regenerative medicine and also used as a model to study the differentiation-induction properties of a variety of biomaterials. This study evaluates the osteoinductive potential of novel hydroxyapatite scaffolds functionalized with a phage-displayed peptide (SC1) selected via biopanning for its similarity to bone matrix proteins. The peptide, identified through sequence alignment as a mimotope of osteonectin (SPARC), was used to functionalize scaffolds. Results from SC1 were gathered at different time points (14, 28 and 46 days) and compared with those from nonfunctionalized hydroxyapatite (HA) scaffolds. In vitro experiments, by seeding human adipose-derived stem cells (hASCs), indicated satisfactory biocompatibility for both types of scaffolds. Histochemical observations showed that SC1, better than HA scaffolds, was able to improve hASC osteogenic differentiation, as evaluated through Alizarin Red staining (showing on average a darker staining of 100%). An increase was also observed, especially at early stages (14 days), for osterix (up to 60% increase) and osteonectin immunoexpression (up to 50% increase). In in vivo experiments, cell-free scaffolds of both types were subcutaneously implanted into the backs of mice and analyzed after 2, 4, 8 and 16 weeks. Also, in this case, SC1 more effectively promoted the osteogenic differentiation of infiltrated resident cells. In particular, increased immunoexpression of osterix and osteonectin (+30% and 35%, respectively) was found already at 2 weeks. It can be concluded that SC1 scaffolds may represent a valuable tool to address critical-sized bone defects. Full article

Bone tissue regeneration is a complex process that takes place at the level of osteoblasts derived from mesenchymal cells and occurs under the action of multiple signaling pathways and through the expression of osteoregenerative markers. The leaf extract of Juglans regia L. (JR) is rich in polyphenols with demonstrated osteoregeneration effects. In the present study, we investigated the extract’s effects on three types of cells with various stages of differentiation: adult mesenchymal stem cells (MSCs), osteoblasts at low passage (O6) and osteoblasts at advanced passage (O10). To assess the efficacy of the walnut leaf extract, in vitro treatments were performed in comparison with ellagic acid (EA) and catechin (CAT). The osteoregenerative properties of the leaf extract were evaluated in terms of cell viability, bone mineralization (by staining with alizarin red) and the expression of osteogenesis markers such as osteocalcin (OC), osteopontin (OPN), dentin matrix acidic phosphoprotein 1 (DMP1) and collagen type 1A. Another compound implicated in oxidative stress response, but also a bone homeostasis regulator, nuclear factor erythroid 2-related factor 2 (NRF2), was studied by immunocytochemistry. Together with collagen amount, alkaline phosphatase (ALP) activity and NF-kB levels were measured in cell lysates and supernatants. The obtained results demonstrate that JR treatment induced osteogenic differentiation and bone mineralization, and it showed protective effects against oxidative stress. Full article

Hydroxyapatite (HA) has become a widely used material for bone grafting and surface modification of titanium-based orthopedic implants due to its excellent biocompatibility. Among various coating techniques, microplasma spraying (MPS) has gained significant industrial relevance. However, the clinical success of HA coatings also depends on their adhesion to the implant substrate. Achieving durable fixation and reliable biological integration of orthopedic implants remains a major challenge due to insufficient coating adhesion and limited osseointegration. This study addresses challenges in dental and orthopedic implantology by evaluating the microstructure, mechanical properties, and biological behavior of bilayer coatings composed of a zirconium (Zr) sublayer and an HA top layer, applied via MPS onto titanium alloy. Surface roughness, porosity, and adhesion were characterized, and pull-off and shear tests were used to assess mechanical performance. In vitro biocompatibility was tested using rat mesenchymal stem cells (MSCs) to model osteointegration. The results showed that the MPS-fabricated Zr–HA bilayer coatings achieved a pull-off strength of 28.0 ± 4.2 MPa and a shear strength of 32.3 ± 3.2 MPa, exceeding standard requirements. Biologically, the HA top layer promoted a 45% increase in MSC proliferation over three days compared to the uncoated titanium substrate. Antibacterial testing also revealed suppression of E. coli growth after 14 h. These findings support the potential of MPS-applied Zr-HA coatings to enhance both the mechanical integrity and biological performance of titanium-based orthopedic implants. Full article

To improve implant osseointegration while preventing infection, we developed a strontium (Sr)-doped Ti₃C₂T_x MXene coating on titanium, aiming to synergistically enhance bone integration and antibacterial performance. MXene is a family of two-dimensional transition-metal carbides/nitrides whose abundant surface terminations endow high hydrophilicity and bioactivity. The coating was fabricated via anodic electrophoretic deposition (40 V, 2 min) of Ti₃C₂T_x nanosheets, followed by SrCl₂ immersion to incorporate Sr²⁺. The coating morphology, phase composition, chemistry, hydrophilicity, mechanical stability, and Sr²⁺ release were characterized. In vitro bioactivity was assessed with rat bone marrow mesenchymal stem cells (BMSCs)—with respect to viability, proliferation, migration, alkaline phosphatase (ALP) staining, and Alizarin Red S mineralization—while the antibacterial efficacy was evaluated against Staphylococcus aureus (S. aureus) via live/dead staining, colony-forming-unit enumeration, and AlamarBlue assays. The Sr-doped MXene coating formed a uniform lamellar structure, lowered the water-contact angle to ~69°, and sustained Sr²⁺ release (0.36–1.37 ppm). Compared to undoped MXene, MXene/Sr enhanced BMSC proliferation on day 5, migration by 51%, ALP activity and mineralization by 47%, and reduced S. aureus viability by 49% within 24 h. Greater BMSCs activity accelerates early bone integration, whereas rapid bacterial suppression mitigates peri-implant infection—two critical requirements for implant success. Sr-doped Ti₃C₂T_x MXene thus offers a simple, dual-function surface-engineering strategy for dental and orthopedic implants. Full article

Background: Bone marrow mesenchymal stem cells (BM-MSCs) are significant in chemo- and radiotherapy resistance. Previous research has focused on BM-MSCs, demonstrating their functional involvement in cancer progression as mediators in the tumor microenvironment. They play multiple roles in tumorigenesis, angiogenesis, and metastasis. BM-MSC-derived exosomes (BM-MSCs-exo) are small vesicles, typically 50–300 nm in diameter, isolated from BM-MSCs. Some studies have demonstrated the tumor-suppressive effects of BM-MSCs-exo. Objective: This study aimed to investigate their role in modulating the impact of chemoradiotherapy (CRT) in different types of cervical cancer spheroid cells. Methods: The spheroids after treatment were subject to size measurement, cell viability, and caspase activity. Then, the molecular mechanism was elucidated by Western blot analysis. Results: We observed a reduction in spheroid size and an increase in cell death in HeLa spheroids, while no significant changes in size or cell viability were found in SiHa spheroids. At the molecular level, CRT treatment combined with BM-MSCs-exo in HeLa spheroids induced apoptosis through the activation of the NF-κB pathway, specifically via the NF-κB1 (P50) transcription factor, leading to the upregulation of apoptosis-related molecules. In contrast, CRT combined with BM-MSCs-exo in SiHa spheroids exhibited an opposing effect: although cellular viability decreased, caspase activity also decreased, which correlated with increased HSP27 expression and the subsequent downregulation of apoptotic molecules. Conclusion: Our study provides deeper insight into the potential of BM-MSCs-exo in cervical cancer treatment, supporting the development of more effective and safer therapeutic strategies for clinical application. Full article

The rabbit is a widely used experimental model for human translational research and stem cell therapy. Many studies have focused on rabbit mesenchymal stem cells from different biological sources for their possible application in regenerative medicine. However, a minimal number of studies have been published aimed at rabbit hematopoietic stem/progenitor cells, mainly due to the lack of specific anti-rabbit CD34 antibodies. In general, CD34 antigen is commonly used to identify and isolate hematopoietic stem/progenitor cells in humans and other animal species. The aim of this study was to develop novel monoclonal antibodies highly specific to rabbit CD34 antigen. We used hybridoma technology, two synthetic peptides derived from predicted rabbit CD34 protein, and a recombinant rabbit CD34 protein as immunogens to produce monoclonal antibodies (mAbs) specific to rabbit CD34. The produced antibodies were screened for their binding activity and specificity using ELISA, flow cytometry, and Western blot analysis. Finally, four mAbs (58/47/26, 58/47/34, 182/7/80, and 575/36/8) were selected for the final purification process. The purified mAbs recognized up to 2–3% of total rabbit bone marrow cells, while about 2% of those cells exhibited CD45 expression, which are likely rabbit primitive hematopoietic stem cells and their hematopoietic progenitors, respectively. The newly generated and purified mAbs specifically recognize CD34 antigen in rabbit bone marrow or peripheral blood and can be therefore used for further immunological applications, to study rabbit hematopoiesis or to establish a new animal model for hematopoietic stem cell transplantation studies. Full article

Purpose: Collagen membranes with biomimetic mineralization are emerging as promising materials for bone regeneration, owing to their high biocompatibility. In this study, we developed a biogenic collagen membrane by combining citrate (C) pretreatment and carboxymethyl chitosan (CMC)-mediated mineralization and further evaluated its bone healing potential. Methods: C-CMC collagen membranes were prepared by lyophilization. The mineral composition and content were tested through X-ray diffraction (XRD), Fourier transform infrared (FTIR), and thermogravimetric analysis (TGA). The micromorphology was observed using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and scanning probe microscopy (SPM). Physical and mechanical properties, including the swelling rate, porosity, hydrophilicity, tensile strength, Young’s modulus, degradation, and barrier function, were also evaluated. Bone mesenchymal stem cells (BMSCs) were cultured in vitro to observe their behavior. An in vivo critical-size rat calvarial defect model was used to validate the effects of the membrane on bone regeneration. Results: The C-CMC collagen membrane was successfully synthesized as a collagen–hydroxyapatite complex with intrafibrillar mineralization, exhibiting improved mechanical properties and an optimal swelling rate, porosity, hydrophilicity, and degradation rate. Additionally, the C-CMC collagen membrane promoted BMSC proliferation, adhesion, and osteogenesis while preventing epithelial cell infiltration. In vivo experiments indicated that C-CMC collagen membranes significantly stimulated bone regeneration without causing systemic toxicity. Conclusions: Our findings suggest that the C-CMC collagen membrane possesses satisfactory physical and mechanical properties, along with good biocompatibility and efficacy in bone defect regeneration, making it a potential candidate for a bioactive guided bone regeneration membrane in clinical applications. Full article

Alveolar bone loss due to trauma, extraction, or periodontal disease often requires bone grafting prior to implant placement. Although human allograft bone is widely used as an alternative to autograft, it has limited osteoinductive potential and a prolonged healing time. Mesenchymal stem cell–conditioned media (MSC-CM), rich in paracrine factors, has emerged as a promising adjunct to enhance bone regeneration. This study evaluated the regenerative effect of MSC-CM combined with human allograft bone in a rabbit calvarial defect model. Bilateral 8 mm defects were created in eight rabbits. Each animal received a human allograft alone (HB group) on one side and an allograft mixed with MSC-CM (HB+GF group) on the other. Histological and histomorphometric analyses were performed at 2 and 8 weeks postoperatively. Both groups showed new bone formation, but the HB+GF group demonstrated significantly greater bone regeneration at both time points (p < 0.05). New bone extended into the defect center in the HB+GF group. Additionally, greater graft resorption and marrow formation were observed in this group at 8 weeks. These findings suggest that MSC-CM enhances the osteogenic performance of human allograft bone and may serve as a biologically active adjunct for bone regeneration. Full article

Lysosomal storage disorders (LSDs) constitute a group of monogenic systemic diseases resulting from deficiencies in specific lysosomal enzymes that cause the intralysosomal accumulation of non- or partially degraded substrates, leading to lysosomal dysfunction. In some cases of LSDs, the bone is more severely affected, thus producing skeletal manifestations in patients. Current therapies, such as enzyme replacement therapy (ERT) and gene therapy (GT), show limited efficacy in correcting skeletal abnormalities. Increasing evidence suggests that microenvironmental disturbances also contribute significantly to disease pathogenesis. Therefore, therapeutic strategies targeting lysosomal dysfunction and microenvironmental dysregulation are needed. Mesenchymal stem-cell-derived extracellular vesicles (MSC-EVs) are emerging as promising candidates in regenerative medicine due to their immunomodulatory, pro-regenerative, and paracrine properties. MSC-EVs have shown potential to modulate the microenvironment and favor tissue repair in bone-related disorders such as osteoarthritis and osteoporosis. Interestingly, MSC-EVs can be engineered to reach the bone and carry therapeutics, including ERT- and GT-related molecules, enabling targeted delivery to hard-to-reach bone regions. This review describes the main features of MSC-EVs and discusses the therapeutic potential of MSC-EVs as a potential cell-free strategy for bone-affected LSDs. Full article