Search Results (852)

Sinus augmentation provides a well-established model for investigating the three-dimensional morphometry and macromolecular dynamics of bone regeneration, particularly when using biphasic calcium phosphate (BCP) graft substitutes. This case series included six biopsies from patients who underwent maxillary sinus augmentation using BCP granules composed of 30% hydroxyapatite (HA) and 70% β-tricalcium phosphate (β-TCP). Bone core biopsies were obtained at healing times of 6 months, 9 months, and 12 months. Histological evaluation yielded qualitative and quantitative insights into new bone distribution, while micro-computed tomography (micro-CT) and Raman microspectroscopy (RMS) were employed to assess the three-dimensional architecture and macromolecular composition of the regenerated bone. Micro-CT analysis revealed progressive maturation of the regenerated bone microstructure over time. At 6 months, the apical regenerated area exhibited a significantly higher mineralized volume fraction (58 ± 5%) compared to the basal native bone (44 ± 11%; p = 0.0170), as well as significantly reduced trabecular spacing (Tb.Sp: 187 ± 70 µm vs. 325 ± 96 µm; p = 0.0155) and degree of anisotropy (DA: 0.37 ± 0.05 vs. 0.73 ± 0.03; p < 0.0001). By 12 months, the mineralized volume fraction in the regenerated area (53 ± 5%) was statistically comparable to basal bone (44 ± 3%; p > 0.05), while Tb.Sp (211 ± 20 µm) and DA (0.23 ± 0.09) remained significantly lower (Tb.Sp: 395 ± 41 µm, p = 0.0041; DA: 0.46 ± 0.04, p = 0.0001), indicating continued structural remodelling and organization. Raman microspectroscopy further revealed dynamic macromolecular changes during healing. Characteristic β-TCP peaks (e.g., 1315, 1380, 1483 cm⁻¹) progressively diminished over time and were completely absent in the regenerated tissue at 12 months, contrasting with their partial presence at 6 months. Simultaneously, increased intensity of collagen-specific bands (e.g., Amide I at 1661 cm⁻¹, Amide III at 1250 cm⁻¹) and carbonate peaks (1065 cm⁻¹) reflected active matrix formation and mineralization. Overall, this case series provides qualitative and quantitative evidence that bone regeneration and integration of BCP granules in sinus augmentation continues beyond 6 months, with ongoing maturation observed up to 12 months post-grafting. 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: Central precocious puberty (CPP), defined as the onset of secondary sexual characteristics before age 8 in girls, is increasingly prevalent worldwide. CPP is often caused by early activation of the HPG axis, leading to accelerated growth and bone maturation. However, the diagnostic accuracy of standard bone age (BA) methods remains uncertain in this context. Objective: To compare the diagnostic accuracy of the Greulich–Pyle atlas (GPA) and Tanner–Whitehouse 3 (TW3) methods in estimating skeletal age in girls with CPP and to assess the predictive value of serum hormone levels for estimating chronological age (CA). Methods: An observational, cross-sectional diagnostic study was conducted, involving n = 109 girls aged 6–12 years with confirmed CPP (Ethics Committee approval: CHUC_2023_86; 13 July 2023). Left posteroanterior hand–wrist (PA–HW) radiographs were assessed using the GPA and TW3 methods. Anthropometric measurements were recorded, and serum concentrations of estradiol, LH, FSH, DHEA-S, cortisol, TSH, and free T4 were obtained. Comparisons between CA and BA estimates were conducted using repeated-measures ANOVA, and ANCOVA was applied to examine the hormonal predictors of CA. Results: Both GPA and TW3 overestimated CA between 7 and 12 years, with the GPA showing larger deviations (up to 4.8 months). The TW3 method provided more accurate estimations, particularly at advanced pubertal stages. Estradiol (η²_p = 0.188–0.197), LH (η²_p = 0.061–0.068), and FSH (η²_p = 0.008–0.023) emerged as the strongest endocrine predictors of CA, significantly enhancing the explanatory power of both radiological methods. Conclusions: The TW3 method demonstrated superior diagnostic accuracy over GPA in girls with CPP, especially between 7 and 12 years. Integrating estradiol, LH, and FSH into BA assessment significantly improved the accuracy, supporting a more individualized and physiologically grounded diagnostic approach. 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

Background/Objectives: Tamoxifen, a selective estrogen receptor modulator widely used as an adjunct in the treatment of breast cancer, has known effects on bone metabolism, although its impact on osseointegration and cellular responses during early bone healing remains unclear. Understanding these effects is essential given the increasing use of dental implants in cancer survivors. The study aimed to observe the influence of tamoxifen on human osteosarcoma (SAOS-2) cells lines, as well on the osseointegration of titanium implants in ovariectomized female rats. Methods: SAOS-2 cells were incubated with Dulbecco’s modified growth medium. Six titanium (Ti) disks were used at each time point. The samples were divided into groups with the presence (TAM, n = 36) or not (CTR, n = 36) of tamoxifen in a concentration of 2 μM. In vivo, 72 animals were divided in groups with bilateral ovariectomy or SHAM and tamoxifen administration or not (15 mg/kg). Cell viability, mineralization rate, and collagen synthesis were assessed, as well as bone/implant contact (BIC) and bone ingrowth (BIN). Results: Tamoxifen caused a decrease in SAOS-2 viability, although an increase in the mineralization rate was observed. In vivo, the TAM groups presented higher BIC and BIN when compared to their control, but a lower percentage of mature collagen cells. Conclusions: Based on our findings, in vitro, the therapy with TAM slightly reduced the viability of SAOS-2 cells while significantly increasing the mineralization rate. In vivo, the therapy positively influenced BIC and BIN during the osseointegration phase. Full article

Red blood cell (RBC) production from bone marrow hematopoietic stem cells (BMHSCs) in vitro overlooks the mechanical signals of the bone marrow niche and overly relies on growth factors. Considering that the fate of hematopoietic stem cells (HSCs) is determined by the natural bone marrow microenvironment, differences in mechanical microenvironments provide a reference for the regulation of HSC differentiation. This study seek to reveal the role of mechanobiology cues in erythropoiesis and provide a new perspective for the design of in vitro erythropoiesis platforms. The hydrogel platforms we designed simulate the stiffness gradient of the bone marrow niche to culture HSCs and induce their differentiation into the erythroid system. Cells on the low-stiffness scaffold have higher potential for erythrocyte differentiation and faster differentiation efficiency and promote erythrocyte differentiation after erythropoietin (EPO) restriction. In vivo transplantation experiments demonstrated that these cells have the ability for continuous proliferation and differentiation into mature erythrocytes. By combining mechanical cues with in vitro erythrocyte production, this method is expected to provide insights for in vitro hematopoietic design and offer a scalable cell manufacturing platform for transfusion medicine. Full article

Mesenchymal stromal cells (MSCs) have demonstrated therapeutic efficacy across numerous clinical applications, with evidence suggesting their paracrine effects, particularly through extracellular vesicles (EVs), possibly driving functional outcomes. In this study we perform the comprehensive characterization of microRNA expression profiles in human MSC-derived EVs (MSC-EV) compared to their parental cells, cultured under clinically relevant xeno-free conditions. MSCs were isolated from the bone marrows of healthy donors and characterised according to the International Society for Cellular Therapy criteria, while MSC-EVs were isolated using differential ultracentrifugation and validated according to the International Society for Extracellular Vesicle guidelines. NanoString profiling identified 590 mature microRNAs expressed across both populations, with 42 being significantly differentially expressed between MSC-EVs and parental MSCs. Five microRNAs were distinctly highly expressed in MSCs and five in MSC-EVs, while fifteen of the top twenty most abundant microRNAs showed high expression in both populations. MicroRNA expression patterns were validated in an independent cohort. Functional pathway analysis of differentially expressed microRNAs showed enrichment of key biological processes including cell proliferation, differentiation, and immune regulation. This standardised profiling approach develops our understanding of MSC/MSC-EV microRNA cargo, using a transparent methodological approach that allows for the improved comparability of datasets for the development and advancement of MSC-EV therapeutics. Full article

This study investigated the effects of Bothrops moojeni (B. moojeni) venom and its high- (HMM) and low-molecular mass (LMM) fractions on human osteoclast (OC) differentiation and function in vitro, aiming to identify novel therapeutics for bone disorders. Venom preparations were applied at 5 µg/mL (crude venom and HMM) or 1 µg/mL (LMM) from day 4 of peripheral blood mononuclear cell (PBMC) differentiation through terminal OC formation, enabling evaluation across early differentiation, fusion, and maturation stages. RNA sequencing revealed 7793 genes common to all experimental groups, with unique gene expression signatures of 149 (control), 221 (HMM), 248 (crude venom), and 60 (LMM) genes, reflecting distinct molecular responses. The negative control PBMC group exhibited 1013 unique genes enriched in immune-related pathways, consistent with their undifferentiated state. Crude venom induced the broadest transcriptional modulation, upregulating key fusion (CD47) and resorption (CTSK) genes, and altering markers of OC differentiation. The HMM fraction predominantly influenced inflammatory and osteoclastogenic pathways, notably TNF and NF-κB signaling, while the LMM fraction selectively regulated fusion-related genes (e.g., CD44) and immune pathways, indicating targeted modulation of OC activity. Cytokine profiling showed that crude venom and HMM suppressed osteoclastogenic cytokines such as IL-1β and IL-6, supporting their potential use in inflammatory bone diseases. Pathway enrichment analyses confirmed these differential effects on immune response and bone resorption mechanisms. Together, these results demonstrate that B. moojeni venom and its fractions differentially impact OC biology, with crude venom exerting broad effects and HMM and LMM fractions offering more specific modulation. Future studies will isolate bioactive components and assess therapeutic efficacy in animal models of osteoporosis and rheumatoid arthritis. Full article

Introduction: Celiac disease (CD) impairs bone development in children through inflammation and nutrient malabsorption. Osteoprotegerin (OPG), a decoy receptor for RANKL, plays a role in bone remodeling and is increasingly recognized as a potential biomarker of bone metabolism and inflammation. However, its clinical significance in pediatric CD remains unclear. Aim: To evaluate the relationship between OPG levels, growth parameters, and delayed bone age in children with CD, and to assess OPG’s potential as a biomarker of bone health and disease activity. Methods: This three-year case–control study included 146 children: 25 with newly diagnosed CD (Group A), 54 with established CD on a gluten-free diet (Group B), and 67 healthy controls (Group C). Participants underwent clinical, anthropometric, and laboratory assessments at baseline and after 6 months (Groups A and B). OPG and osteocalcin were measured, and bone age was assessed radiologically. Statistical analyses included ANOVA, Spearman’s correlations, and binomial logistic regression. Results: OPG levels were highest in newly diagnosed children (Group A), showing a non-significant decrease after gluten-free diet initiation. OPG correlated negatively with age and height in CD patients and controls, and positively with hemoglobin and iron in Group B. Logistic regression revealed no significant predictive value of OPG for delayed bone age, although a trend was observed in Group B (p = 0.091). Children in long-term remission exhibited bone maturation patterns similar to healthy peers. Conclusions: OPG levels reflect disease activity and growth delay in pediatric CD but lack predictive power for delayed bone age. While OPG may serve as a secondary marker of bone turnover and inflammatory status, it is not suitable as a standalone biomarker for skeletal maturation. These findings highlight the need for integrative biomarker panels to guide bone health monitoring in children with CD. Full article

Background/Objectives: Hypertension is a major contributor to cardiovascular diseases and is often intensified by psychological stress, which can also affect bone metabolism. Although both conditions independently compromise bone health, their combined impact—particularly under acute and chronic stress—remains unclear. This pilot study aimed to assess the effects of such stressors on bone structure in spontaneously hypertensive rats (SHRs). Methods: Forty male rats, both normotensive and SHRs, were randomly assigned to control, acute stress, or chronic stress groups. Acute stress involves a single 2 h physical restraint. Chronic stress was induced over 10 days using alternating stressors: agitation, forced swimming, physical restraint, cold exposure, and water deprivation. Tibial bones were analyzed by microcomputed tomography (micro-CT), and histology was performed using Hematoxylin and Eosin and Masson’s Trichrome stains. Results: Micro-CT showed increased trabecular bone volume in normotensive rats under chronic stress, whereas SHRs displayed impaired remodeling under both stress types. Histological analysis revealed preserved connective tissue overall but evident changes in growth plate structure among stressed rats. SHRs exhibited exacerbated trabecular formation and cartilage abnormalities, including necrotic zones. Conclusions: Both acute and chronic stress, especially in the context of hypertension, negatively affect bone remodeling and maturation. Despite the absence of overt inflammation, structural bone changes were evident, indicating potential long-term risks. These findings highlight the importance of further studies on stress–hypertension interactions in bone health as well as the exploration of therapeutic approaches to mitigate skeletal damage under such conditions. Full article

Background: Radiographic evaluation of bone regeneration following maxillary sinus floor elevation commonly emphasizes volumetric gains. However, the qualitative microarchitecture of the regenerated bone, particularly when assessed via two-dimensional imaging modalities, such as panoramic radiographs, remains insufficiently explored. This study aimed to evaluate early trabecular changes in grafted maxillary sinus regions using fractal dimension, first-order statistics, and gray-level co-occurrence matrix analysis. Methods: This retrospective study included 150 patients who underwent maxillary sinus floor augmentation with bovine-derived xenohybrid grafts. Postoperative panoramic radiographs were analyzed at 6 months to assess early healing. Four standardized regions of interest representing grafted sinus floors and adjacent tuberosity regions were analyzed. Image processing and quantitative analyses were performed to extract fractal dimension (FD), first-order statistics (FOS), and gray-level co-occurrence matrix (GLCM) features (contrast, homogeneity, energy, correlation). Results: A total of 150 grafted sites and 150 control tuberosity sites were analyzed. Fractal dimension (FD) and contrast values were significantly lower in grafted areas than in native tuberosity bone (p < 0.001 for both), suggesting reduced trabecular complexity and less distinct transitions. In contrast, higher homogeneity (p < 0.001) and mean gray-level intensity values (p < 0.001) were observed in the grafted regions, reflecting a more uniform but immature trabecular pattern during the early healing phase. Energy and correlation values also differed significantly between groups (p < 0.001). No postoperative complications were reported, and resorbable collagen membranes appeared to support graft stability. Conclusions: Although the grafted sites demonstrated radiographic volume stability, their trabecular architecture remained immature at 6 months, implying that volumetric measurements alone may be insufficient to assess biological bone maturation. These results support the utility of advanced textural and fractal analysis in routine imaging to optimize clinical decision-making regarding implant placement timing in grafted sinuses. Full article

Although publications have documented the osteo-inductive effects of various bioactive materials on tissue sections, the associated morphologic patterns of tissue remodeling pathways at the cellular level have not been detailed. Therefore, we present a comparative histopathological follow-up evaluation of bone defect repair mediated by silica aerogels and methacrylate hydrogels over a 6-month period, which is the widely accepted time course for complete resolution. Time-dependent microscopic analysis was conducted using the “critical size model”. In untreated rat calvaria bone defects (control), re-ossification exclusively started at the lateral regions from the edges of the remaining bone. At the 6th month, only a few new bones were formed, which were independent of the lateral ossification. The overall ossification resulted in a 57% osseous encroachment of the defect. In contrast, aerogels (AE), hydrogels (H), and their β-tricalcium-phosphate (βTCP)-containing counterparts, which were used to fill the bone defects, characteristically induced rapid early ossification starting from the 1st month. This was accompanied by fibrous granulomatous inflammation with multinucleated giant macrophages, which persisted in decreasing intensity throughout the observational time. In addition to lateral ossification, multiple and intense intralesional osseous foci developed as early as the 1st month, and grew progressively thereafter, reflecting the osteo-inductive effects of all compounds. However, both βTCP-containing bone substituents generated larger amounts and more mature new bones inside the defects. Nevertheless, only 72.8–76.9% of the bone defects treated with AE and H and 80.5–82.9% of those treated with βTCP-containing counterparts were re-ossified by the 6th month. Remarkably, by this time, some intra-osseous hydrogels were found, and traces of silica from AE were still detectable, indicating these as the causative agents for the persistent osseous–fibrous granulomatous inflammation. When silica or methacrylate-based bone substituents are used, chronic ossifying fibrous granulomatous inflammation develops. Although 100% re-ossification takes more than 6 months, by this time, the degree of osteo-fibrous solidification provides functionally well-suited bone repair. Full article

The reconstruction of a severely resorbed alveolar bone is a significant challenge in dental implantology and maxillofacial surgery. Traditional bone grafting materials, including autogenous, allogeneic, xenogeneic, and alloplastic materials, have limitations such as donor site morbidity, limited availability, and prolonged maturation periods. To address these challenges, recombinant human bone morphogenetic protein-2 (rhBMP-2) has emerged as a potent osteoinductive factor that facilitates bone regeneration without the need for additional donor site surgery. This study introduces a box technique which combines rhBMP-2 (CowellBMP^®, Cowellmedi, Busan, Republic of Korea) with a 3D-preformed titanium mesh (3D-PFTM), utilizing a mixture of allografts and xenografts for horizontal and vertical alveolar ridge augmentation. The technique leverages the structural stability provided by the OssBuilder^® (Osstem, Seoul, Republic of Korea), a preformed titanium mesh, that allows for simultaneous implant placement and vertical ridge augmentation. This technique not only reduces the treatment time compared to traditional methods but also minimizes post-operative discomfort by eliminating the need for autogenous bone harvesting. Clinical outcomes from this technique demonstrate successful bone regeneration within a shorter period than previously reported techniques, with excellent bone quality and implant stability being observed just four months after vertical augmentation. In conclusion, the so called BOXAM (BMP-2, Oss-builder, Xenograft, Allograft, Maintenance) technique presents a promising therapeutic strategy for alveolar bone reconstruction, particularly in cases of severe bone resorption. Further studies are needed to evaluate the long-term outcomes and potential limitations of this approach, especially in scenarios where the inferior alveolar nerve proximity poses challenges for fixture placement. Full article

Background: The bone morphogenetic protein (BMP) signaling pathway is essential for lung development. BMP4, a key regulator, binds to type I (BMPR1) and type II (BMPR2) receptors to initiate downstream signaling. While the inactivation of Bmpr1a and Bmpr1b leads to tracheoesophageal fistulae, the role of BMPR2 mutations in lung epithelial development remains unclear. Methods: We generated induced pluripotent stem cells (iPSCs) from a patient carrying a BMPR2 mutation (c.631C>T), and gene-corrected isogenic controls were created using CRISPR/Cas9. These iPSCs were differentiated into lung progenitor cells and subsequently cultured to generate alveolar and airway organoids. The differentiation efficiency and epithelial lineage specification were assessed using immunofluorescence, flow cytometry, and qRT-PCR. Results: BMPR2-mutant iPSCs showed no impairment in forming a definitive or anterior foregut endoderm. However, a significant reduction in lung progenitor cell differentiation was observed. Further, while alveolar epithelial differentiation remained largely unaffected, airway organoids derived from BMPR2-mutant cells exhibited impaired goblet and ciliated cell development, with an increase in basal and club cell markers, indicating skewing toward undifferentiated airway cell populations. Conclusions: BMPR2 dysfunction selectively impairs late-stage lung progenitor specification and disrupts airway epithelial maturation, providing new insights into the developmental impacts of BMPR2 mutations. Full article

Background/Objectives: Hypohidrotic ectodermal dysplasia (HED) is a rare hereditary disorder affecting ectoderm-derived tissues including teeth, hair, and sweat glands. The dental abnormalities associated with HED, such as oligodontia and conical teeth, often result in significant functional, esthetic, and psychosocial challenges, particularly during childhood. Methods: A 10-year-old child presented with psychosocial concerns related to missing and malformed teeth. Clinical examination revealed oligodontia, conical anterior teeth, and a resorbed mandibular ridge. Based on clinical findings and a positive family history, a diagnosis of HED with significant dental involvement was confirmed. Results: A conservative prosthodontic approach was selected. A maxillary overdenture was fabricated over the retained primary teeth to enhance retention and preserve the alveolar bone, and a resin-bonded bridge was placed in the mandible due to poor ridge anatomy. The treatment restored oral function and esthetics and improved the child’s self-esteem. A recall visit after three months confirmed good prosthesis adaptation and a positive response from the patient and parents. Conclusions: This case highlights the importance of early, conservative, and developmentally appropriate prosthetic rehabilitation in pediatric patients with HED. Interim prostheses can significantly improve oral function, appearance, and psychosocial well-being while preserving future treatment options as the child matures. Full article