The prognosis of osteosarcoma has improved little over the past few decades, with radioresistance being a contributing factor. Effective radiosensitizing targets and novel mechanisms for treating osteosarcoma are urgently needed. Research on the impact of regulating differentiation levels on the radiosensitivity of malignant tumors is limited. This study aimed to explore the efficacy of ITGB3 as a novel radiosensitizing target in osteosarcoma and to explore whether the modulation of osteogenic differentiation plays a role in mediating the radiosensitizing effect.

RNA sequencing was utilized to screen for potential targets that affect the radiosensitivity of osteosarcoma. In vitro assays examining cell viability, apoptosis, proliferation, migration, and invasion were conducted to verify the radiosensitizing effect of ITGB3-knockdown (KD). Furthermore, in vivo validation was performed by constructing mouse models with subcutaneous and orthotopic tibial tumors. Rescue experiments involving siRNAs and molecular inhibitors were performed to explore and validate the mechanisms through which ITGB3-KD exerts a radiosensitizing effect in vitro and in vivo. Additionally, osteogenic differentiation cultures of osteosarcoma cells were conducted as auxiliary validation for the radiosensitizing mechanism.

ITGB3-KD had a radiosensitizing effect on osteosarcoma in vitro by inhibiting cell viability, proliferation, migration, and invasion and promoting apoptosis. ITGB3-KD radiosensitized osteosarcoma in vivo in subcutaneous and orthotopic tibial tumor models. ITGB3-KD upregulated the JNK/c-JUN pathway, and rescue experiments with a JNK inhibitor revealed that the activation of this pathway was crucial for the upregulation of osteogenic markers such as RUNX2, OCN, and OPN, as well as for promoting apoptotic pathways. siRNA-based rescue experiments indicated that the upregulation of RUNX2 mediated the proapoptotic radiosensitizing effects of ITGB3-KD. Culture in osteogenic differentiation medium promoted osteosarcoma radiosensitization by enhancing the osteogenic differentiation status, working synergistically with ITGB3-KD.

Our findings indicate that ITGB3-KD enhances radiosensitivity in osteosarcoma by promoting osteogenic differentiation and apoptosis through activation of the JNK/c-JUN/RUNX2 pathway, identifying ITGB3 as a candidate therapeutic target and implicating JNK/c-JUN/RUNX2 signaling as a modulatory axis for improving the response to radiation of osteosarcoma.

Background/Objectives: Dental pulp stem cells (DPSCs) are of significant interest due to their mesenchymal lineage and relative availability from extracted teeth. This study aims to examine the relationship between fibronectin-adherent, non-fibronectin-adherent, and explant-derived DPSC populations in terms of the population doubling rate in culture and the expression of mesenchymal cell surface markers and their capacity for osteodifferentiation. Methods: Human pulp tissue was removed from healthy extracted human teeth, enzymatically digested prior to seeding onto fibronectin-coated plates, and left to adhere for 20 min, yielding a fibronectin-adherent population. The remaining non-adherent cells were transferred and designated 'non-fibronectin-adherent.' Intact pulp was placed on uncoated plastic for 5 days, with the migrated cells designated 'explant-derived'. DPSCs from these populations were examined in terms of population doubling rates, the expression of CD90, CD44, CD105, and CD73, and the expression of RUNX2, SPP1, and BGLAP after 7 days in osteoinductive media. Results: The fibronectin-adherent cells had the greatest population doubling over time. All populations demonstrated comparable percentages of cells positive for mesenchymal markers, though individual marker expression varied slightly. The explant-derived cells showed increased expression of RUNX2 after 7 days in osteoinductive media, while the treated single-cell-suspension-derived populations showed increased expression of SPP1 mRNA. Conclusions: Fibronectin enrichment resulted in a population with the greatest rate of population doubling over extended culture compared to the other two populations. The proportion of cells positive for all four mesenchymal surface markers was the same between populations. The fibronectin-adherent and non-adherent cultures may have responded more rapidly to osteoinductive media than the explant-derived cells.

Traumatic defects or non-union fractures presents a substantial challenge in the fields of tissue engineering and regenerative medicine. Although synthetic calcium phosphate-based biomaterials (CaPs) such as dibasic calcium phosphate anhydrate (DCPA) are commonly employed for bone repair, their inadequate cellular immune responses significantly impede sustained degradation and optimal osteogenesis. In this study, drawing inspiration from the key structure of an acidic non-collagenous protein-CaP complex (ANCPs-CaP) essential for natural bone formation, we prepared biomimetic mineralized dibasic calcium phosphate (MDCPA). This preparation utilized plant-derived non-collagenous protein Zein as the organic template and acidic artificial saliva as the mineralization medium. Physicochemical property analysis revealed that MDCPA is a complex of Zein and DCPA, which mimics the composite of the natural ANCP-CaP. Moreover, MDCPA exhibited enhanced biodegradability and osteogenic potential. Mechanistic insight revealed that MDCPA can be phagocytized and degraded by macrophages via the FCγRIII receptor, leading to the release of interleukin 27 (IL-27), which promotes osteogenic differentiation by osteoimmunomodulation. The critical role of IL-27 in osteogenesis is further confirmed using IL-27 gene knockout mice. Additionally, MDCPA demonstrates effective healing of critical-sized defects in rat cranial bones within only 4 w, providing a promising basis and valuable insights for critical-sized bone defects regeneration.

Phytochemicals, which are bioactive compounds contained in fruits, vegetables, and teas, have a positive effect on human health by having anti-inflammatory, antioxidant, and anticarcinogenic effects. Several studies have highlighted the ability of bioactive compounds to activate key cellular enzymes associated with important signaling pathways related to cell division and proliferation, as well as their role in inflammatory and immunological responses. Some phytochemicals are associated with increased proliferation, differentiation, and expression of markers related to osteogenesis, bone formation, and mineralization by activating various signaling pathways. The objective of this study was to clarify which bioactive compounds present in fruits have osteogenic effects on mesenchymal stem cells and the possible associated mechanisms. A literature search was conducted in the LILACS, MEDLINE, and PubMed databases for pertinent articles published between 2014 and 2024. This review included 34 articles that report the osteogenic effects of various bioactive compounds found in different fruits. All the articles reported that phytochemicals play a role in enhancing the regenerative properties of mesenchymal cells, such as proliferation, osteogenic differentiation, secretion of angiogenic factors, and extracellular matrix formation. This review highlights the potential of these phytochemicals in the prevention and treatment of bone diseases. However, more studies are recommended to identify and quantify the therapeutic dose of phytochemicals, investigate their mechanisms in humans, and ensure their safety and effectiveness for health, particularly for bone health.

Malocclusion can be corrected with orthodontic treatment to improve function and aesthetics. Orthodontic treatment patients have the potential to produce greater Reactive Oxygen Species (ROS), as evidenced by an increase in the Oxidative Status Index (OSI) a week after treatment. As a result, oxidative stress may induce an imbalance of bone remodeling through intensifying osteoclastogenesis by expressing pro-inflammatory cytokine, namely Interleukin-6 (IL-6). The worst pathological condition that can occur is Orthodontic-Induced Root Resorption (OIRR), a resorptive area on the root that is unwanted from orthodontic treatment. OIRR incidence is reported to be more than 90 % asymptomatic. Using Forastero cacao bean (Theobroma cacao L.) extract gel as a natural antioxidant and anti-inflammatory compound is expected to be able to prevent excess ROS, which triggers an increase in various pro-inflammatory cytokines, especially IL-6, which plays a role in the bone resorption pathway, thus reducing the incidence of OIRR and making orthodontic treatment successful through balanced bone remodeling.

This study aimed to investigate the effect of Forastero cacao bean (Theobroma cacao L.) extract gel on the decrease of IL-6 cytokine expressed by osteoblasts, osteoclasts, and osteocytes in the OIRR model of male Wistar rats.

IL-6 positive osteoblasts, osteoclasts, and osteocytes decreased significantly after 8 % Forastero cacao bean extract gel-treated, as seen in T7 and T14 groups compared to C-7 and C-14 groups (p < 0.05).

8 % Forastero cacao bean extract gel decreased IL-6-positive osteoblasts, osteoclasts, and osteocytes in the tension side of the alveolar bone.

Osteoporosis, characterized by reduced bone mineral density and increased fracture risk, poses a significant health challenge, particularly for aging populations. Systemic treatments often lead to adverse side effects, emphasizing the need for localized solutions. This study introduces a 3D-printed polycaprolactone (PCL) scaffold embedded with strontium-substituted mesoporous bioactive glass nanoparticles (Sr-MBGNPs) and icariin (ICN) for the targeted regeneration of osteoporotic bone. The scaffold was characterized using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), ion release studies, and cellular assays, which confirmed its dual functionality in both enhancing osteoblast proliferation and differentiation and inhibiting osteoclastogenesis. The optimized Sr-MBGNP concentration ensured sustained ion release, superior hydrophilicity, and bioactivity without compromising scaffold integrity. Additionally, e-jet printing provided high precision and uniform pore sizes conducive to cellular activity. This novel scaffold platform demonstrates a promising localized treatment strategy, reducing systemic side effects while improving fixation stability. The innovative integration of Sr-MBGNPs and ICN highlights its potential to revolutionize osteoporosis therapy by promoting bone regeneration and mitigating bone resorption.

Human Maxillary Sinus Membrane Stem Cells (hMSMSCs) contribute significantly to bone formation following maxillary sinus floor augmentation (MSFA). The biological behavior of mesenchymal stem cells is notably influenced by varying concentrations of magnesium (Mg2+), strontium (Sr2+), and zinc (Zn2+) ions; however, their specific effects on hMSMSCs have not been comprehensively studied. We isolated hMSMSCs and identified their mesenchymal stem cell characteristics by flow cytometry and multilineage differentiation experiments. Subsequently, the hMSMSCs were cultured in media containing different concentrations of these metal ions. The proliferation and viability of hMSMSCs were assessed using CCK-8 and Calcein AM/PI staining. After osteogenic induction, cells were evaluated for alkaline phosphatase (ALP) activity, ALP staining, and Alizarin Red staining. Additionally, qRT-PCR was used to detect differences in osteogenic gene expression, and immunofluorescence staining was used to observe variations in OCN protein levels. The results indicated that 1 mM Mg2+, 0.01 mM Sr2+, and 0.001 mM Zn2+ significantly improved the proliferation and activity of hMSMSCs. These concentrations also notably enhanced ALP secretion, increased bone-related gene expression, and augmented osteocalcin expression and formation of extracellular calcium nodules, thereby improving osteogenic differentiation. However, higher concentrations of Mg2+, Sr2+, and Zn2+ decreased cell viability and osteogenic differentiation. Mg2+, Sr2+, and Zn2+ promote osteogenic differentiation and proliferation of hMSMSCs in a concentration-dependent manner, indicating that the type and concentration of ions in the extracellular environment can significantly alter hMSMSCs behavior, which is a crucial consideration for material design in maxillary sinus elevation applications.

Osteoporosis, characterized by an increased risk of fractures, represents a significant global public health issue. Natural compounds have emerged as promising candidates for addressing this condition. Shikonin, derived from Lithospermum erythrorhizon as a purple-red naphthoquinone pigment, exhibits a diverse array of biological activities, including antibacterial, anti-inflammatory, and anticancer properties. Despite the well-documented bone-protective properties of shikonin, the precise molecular mechanisms underlying its role in the differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) into osteoblasts, along with its implications on angiogenesis, are not fully elucidated. Our study showcases shikonin's ability to stimulate the differentiation of BMSCs into osteoblasts, leading to an upregulation of osteoblast-specific marker genes such as OC, Runx2, BMP2, and ALP. Furthermore, shikonin intervention triggers the upregulation of phosphorylation of p38, ERK, and JNK in the MAPK signaling pathway. Furthermore, shikonin has been shown to enhance the migration and angiogenic capabilities of human umbilical vein endothelial cells (HUVECs). Notably, the augmentation of HUVEC migration by shikonin can be counteracted by the addition of a JNK inhibitor. Furthermore, our findings indicate that shikonin effectively improves osteoporosis in aged mice by promoting osteoblast differentiation. In summary, our study elucidates the molecular mechanisms through which shikonin exerts its beneficial effects in the treatment of osteoporosis, highlighting its potential as a novel therapeutic option for both the prevention and management of this condition.

Electrical stimulation has been used with tissue engineering-based models to develop three-dimensional (3D), dynamic, research models that are more physiologically relevant than static two-dimensional (2D) cultures. For bone tissue, the effect of electrical stimulation has focused on promoting healing and regeneration of tissue to prevent bone loss. However, electrical stimulation can also potentially affect mature bone parenchymal cells such as osteoblasts to guide bone formation and the secretion of paracrine or endocrine factors. Due to a lack of physiologically relevant models, these phenomena have not been studied in detail. In vitro electrical stimulation models can be useful for gaining an understanding of bone physiology and its effects on paracrine tissues under different physiological and pathological conditions. Here, we use a 3D, dynamic, in vitro model of bone to study the effects of electrical stimulation conditions on protein and gene expression of SaOS-2 human osteosarcoma osteoblast-like cells. We show that different stimulation regimens, including different frequencies, exposure times, and stimulation patterns, can have different effects on the expression and secretion of the osteoblastic markers alkaline phosphatase and osteocalcin. These results reveal that electrical stimulation can potentially be used to guide osteoblast gene and protein expression.

Titanium (Ti) implant osseointegration is regulated by the crosstalk among bone cells that are affected by epigenetic machinery, including the regulation of long non-coding RNAs (lncRNAs). Nanotopography Ti (Ti Nano) induces the differentiation of osteoblasts that are inhibited by osteoclasts through epigenetic mechanisms. Thus, we hypothesize that osteoclasts affect lncRNA expression in Ti Nano-cultivated osteoblasts. Osteoblasts were grown on Ti Nano and Ti Control that were then co-cultured with osteoclasts for 48 h. Using RNAseq, we identified 252 modulated lncRNAs in osteoblasts regulated by both surfaces of Ti, but mainly in Ti Nano-cultivated osteoblasts. A negative correlation was observed between Kcnq1ot1 and the mRNAs of Alpl, Bglap, Bmp8a, Col1a1, and Vim in Ti Nano-cultivated osteoblasts with osteoclasts. The pull-down indicated that Bglap mRNA is a direct target of Kcnq1ot1, with enhanced physical interaction in Ti Nano-cultivated osteoblasts, and greater osteoclast inhibition than the Ti Control. The bone marker expression at the levels of mRNA and protein were downregulated by the Kcnq1ot1 silencing, indicating its pivotal role in osteoblast differentiation. These results showed that nanostructured Ti surface modulates the osteoblast-osteoclast crosstalk, at least in part, through the regulation of lncRNA expression in osteoblasts. We demonstrate that the lncRNA Kcnq1ot1 directly interacts with Bglap mRNA, and this interaction is enhanced by nanotopography and reduced by osteoclasts with greater intensity in Ti Nano-cultivated osteoblasts. These findings confirm the molecular mechanisms associated with the high osteogenic potential of nanotopography and can potentially support osteointegration of dental and skeletal prostheses.

Titanium nanotubular surfaces have been extensively studied for their potential use in biomedical implants due to their ability to promote relevant phenomena associated with osseointegration, among other functions. However, despite the large body of literature on the subject, potential synergistic/antagonistic effects resulting from the combined influence of environmental variables and nanotopographical cues remain poorly investigated. Specifically, it is still unclear whether the nanotube-induced variations in cellular activity are preserved across different biochemical contexts. To bridge this gap, this study systematically evaluates the combined influence of nanotopographical cues and environmental factors on human MG63 osteoblastic cells. To this end, we capitalized on a triphasic anodization protocol to create nanostructured surfaces characterized by an average nanotube inner diameter of 25 nm (NT1) and 82 nm (NT2), as well as a two-tiered honeycomb (HC) architecture. A variable glucose content was chosen as the environmental modifier due to its well-known ability to affect specific functions of MG63 cells. Alkaline phosphatase (ALP), viability/metabolic activity and proliferation were quantified to identify the suitable preconditioning window required for dictating a change in behaviour without significantly damaging cells. Successively, a combination of immunofluorescence, colorimetric assays, live cell imaging and western blots quantified viability/metabolic activity and cell proliferation, migration and differentiation as a function of the combined effects exerted by the nanostructured substrates and the glucose content. To achieve a thorough understanding of MG63 cell adaptation and response, a comparative analysis table that includes and systematically cross-analyzes all variables from this study was used for interpretation and discussion of the results. Taken together, we have demonstrated that all surfaces mitigate the negative effects of high glucose. However, nanotubular topographies, particularly NT2, elicit a more beneficial outcome in high glucose in respect to untreated titanium. In addition, while NT1 surfaces are associated with the most stable cellular response across varying glucose levels, the NT2 and HC substrates exhibit the strongest enhancement of cell migration, viability/metabolism and differentiation. Moreover, shorter-term processes such as adhesion and proliferation are favored on untreated titanium, while anodized samples support later-term events. Lastly, the role of anodized surfaces is dominant over the effects of environmental glucose, underscoring the importance of carefully considering nanoscale surface features in the design and development of cell-instructive titanium surfaces.

Bone tissue engineering is a promising approach to overcome the limitations of traditional autograft bone transplantation. Graphene quantum dots (GQDs) have been suggested as an enhancement for osteogenic differentiation. This study aimed to investigate the ability of the fibrin hydrogel scaffold in the presence of graphene quantum dots to promote osteogenic differentiation of human Wharton's jelly-derived mesenchymal stem cells (hWJ-MSCs). The hWJ-MSCs were isolated from the Wharton's jelly of the human umbilical cord using a mechanical method. Fibrin hydrogel scaffolds were prepared by mixing 15 µl of thrombin solution with fibrinogen solution. GQDs were incorporated into the scaffolds at concentrations of 0, 5, and 10 µg/ml. Cell viability was determined through DAPI staining and the MTT assay. Osteogenic differentiation was assessed by measuring alkaline phosphatase (ALP) activity, quantifying calcium deposition using Alizarin Red S staining, and analyzing the gene expression of BGLAP, COL1A1, Runx-2 and ALP via qPCR. Scanning electron microscopy (SEM) was employed to analyze the scaffold architecture. SEM analysis revealed that the fibrin hydrogel exhibited a suitable architecture for tissue engineering, and DAPI staining confirmed cell viability. The MTT results indicated that the GQDs and fibrin hydrogel scaffold exhibited no cytotoxic effects. Furthermore, the incorporation of GQDs at a concentration of 10 µg/ml significantly enhanced ALP activity, calcium deposition, and the expression of osteogenesis-related genes compared to the control. The findings suggest that the combination of fibrin hydrogel and GQDs can effectively promote the osteogenic differentiation of hWJ-MSCs, contributing to the advancement of bone tissue engineering.

Estrogen deficiency contributes to osteoporosis and can therefore compromise the peri-implant bone. Hence, this study evaluated peri-implant bone healing when Rubus coreanus (RC) was administered orally in ovariectomized and healthy rats. Forty 4-month-old female rats were divided into four groups: SHAM (healthy rats), SHAM/RC (healthy rats treated with RC), OVX (ovariectomized rats), and OVX/RC (ovariectomized rats treated with RC). The oral administration of RC started thirty days after ovariectomy, and implant placement into the rat tibia occurred ninety days after the ovariectomy. Euthanasia occurred sixty days after implantation. The analyses performed included removal torque, RT-PCR, confocal microscopy, and immunolabeling. A significance level of p < 0.05 was considered for all tests. The highest reverse torque values were observed in the SHAM/RC group, followed by the OVX/RC group. Confocal microscopy showed the greatest bone biomineralization in the SHAM/RC group, followed by the OVX/RC group. RT-PCR data indicated that RC decreased the RANKL/OPG ratio in both conditions. Immunohistochemistry demonstrated a balance between bone formation and resorption in all groups, especially stimulating osteoblastogenesis in both treated groups. In conclusion, RC enhanced peri-implant bone healing and biomineralization in both healthy and ovariectomized rats, with stronger effects in healthy rats, suggesting that estrogen may enhance its efficacy. These findings support RC's potential as a prophylactic and therapeutic agent.

Bone defects restoration has always been an arduous challenge in the orthopedic field due to the limitations of conventional grafts. Bone tissue engineering offers an alternative approach by using biomimetic materials, stem cells, and growth factors that are able to improve the regeneration of bone tissue. Different biomaterials have attracted great interest in BTE applications, including the poly(3-hexylthiofene) (P3HT) conductive polymer, whose primary advantage is its capability to provide a native extracellular matrix-like environment. Based on this evidence, in this study, we evaluated the biological response of human adipose-derived mesenchymal stem cells cultured on P3HT thin polymer film for 14 days. Our results suggest that P3HT represents a good substrate to induce osteogenic differentiation of osteoprogenitor cells, even in the absence of specific inductive growth factors, thus representing a promising strategy for bone regenerative medicine. Therefore, the system provided may offer an innovative platform for next-generation biocompatible materials for regenerative medicine.

Osteoarthritis (OA) is a significant condition that profoundly impacts synovial joints, including cartilage and subchondral bone plate. Biomaterials that can impede OA progression are a promising alternative or supplement to anti-inflammatory and surgical interventions. Magnesium (Mg) alloys known for bone regeneration potential were assessed in the form of Mg microparticles regarding their impact on tissue regeneration and prevention of OA progression. In vitro assays based on mesenchymal stem cells (SCP-1) were applied to evaluate the Mg microparticle's compatibility and function. Biocompatibility documented through live-dead staining and lactate dehydrogenase assay revealed a 90% cell viability at a concentration below 10 mM after 3 days of exposure. An in vitro OA model based on the supplementation of the cytokines IL-1β, and TNF-α was established and disclosed the effect of Mg degradation products in differentiating SCP-1 cells. Sustained differentiation was confirmed through extracellular matrix staining and increased gene marker expression. The Mg supplementation reduced the release of inflammatory cytokines (IL-6 and IL-8) while promoting the expression of proteins such as collagen X, collagen I, and osteopontin in a time-dependent manner. The in vitro study suggests that Mg microparticles hold a therapeutic potential for OA treatment with their ability to support bone and cartilage repair mechanisms even under inflammatory conditions.

The present research aims to develop a Ca-Zn ion-incorporated surface functionalized 3D Ti cancellous bone scaffold for bone defect repair. The scaffold is designed to mimic human cancellous bone architecture through selective laser melting-based additive manufacturing. The chemical-based surface modification approach employed here created a Ca and Zn ions incorporated nano-porous surface layer with enhanced surface roughness and hydrophilicity. The modified biomimetic scaffold improved the corrosion resistance behaviour with ICORR and ECORR values of 0.174 mA and 0.0097 V respectively. It is learned that incorporating Zn as ZnO over the scaffold has antibacterial activity against Staphylococcus aureus and Escherichia coli. The cellular response of MG-63 to the modified scaffold was evaluated through in-vitro studies which focus on the cytocompatible properties. The intra-osseous biomimetic Ti-Na-Ca:Zn 3D scaffold revealed significant improvement in the osseointegration capabilities in terms of bone mineral density (BMD) and bone volume/total volume (BV/TV) in the rabbit model. The osseointegration potential at the Ti-Na-Ca:Zn interface was evidenced by histological analysis and micro-CT imaging. In addition to this, the remarkable upregulation of osteogenic genes such as OCN, COL1A1, OPN, ALP, RUNX2, and OSX evidences the dynamics of the osseointegration process at each surgical period. This Ca and Zn surface functionalised porous architecture of the 3D Ti cancellous bone scaffold with enhanced biological response and bone integration can potentially give insights into implant customisation along with improved clinical outcomes.

Background and Objectives: Vascular endothelial growth factor (VEGF) is a protein which stimulates the formation of new blood vessels, playing a crucial role in processes such as wound healing and tumor growth. Methods: This study investigated the effects of VEGF on cell viability and osteogenic differentiation in mesenchymal stem cell (MSC) spheroids. Stem cell spheroids were fabricated using concave microwells and cultured with VEGF at concentrations of 0, 0.01, 0.1, 1, and 10 ng/mL. Morphological assessments were conducted on days 1, 3, 5, and 7, while cell viability was evaluated using the LIVE/DEAD assay and Cell Counting Kit-8. Alkaline phosphatase activity (ALP) and calcium deposition were measured to assess osteogenic differentiation, and qPCR was used to analyze osteogenic marker expression. Results: The spheroids maintained their shape across all VEGF concentrations, with the largest diameter being at 0.01 ng/mL on day 1, which decreased over time. Cell viability was highest at 0.01 ng/mL VEGF, while calcium deposition peaked at 0.1 ng/mL. Osteogenic markers, including RUNX2, osteocalcin, and COL1A1, showed significant upregulation at 1 ng/mL VEGF. Conclusions: These results suggest that VEGF enhances early osteogenic differentiation in MSC spheroids, indicating its potential for bone repair and tissue regeneration. VEGF could be applied in clinical settings for bone healing, fracture repair, and regenerative dentistry treatments.

The present study investigates the influence of nitrosamines and etoposide on mesenchymal stromal cells (MSCs) in a differentiation state- and biological age-dependent manner. The genotoxic effects of the agents on both neonatal and adult stem cell populations after treatment, before, or during the course of differentiation, and the sensitivity of the different MSC types to different concentrations of MNU or etoposide were assessed. Hereby, the multipotent differentiation capacity of MSCs into osteoblasts, adipocytes, and chondrocytes was analyzed. Our findings reveal that while all cell types exhibit DNA damage upon exposure, neonatal CB-USSCs demonstrate enhanced resistance to genotoxic damage compared with their adult counterparts. Moreover, the osteogenic differentiation of MSCs was more susceptible to genotoxic damage, whereas the adipogenic and chondrogenic differentiation potentials did not show any significant changes upon treatment with genotoxin. Furthermore, we emphasize the cell-specific variability in responses to genotoxic damage and the differences in sensitivity and reaction across different cell types, thus advocating the consideration of these variabilities during drug testing and developmental biological research.

Osteoporosis, a common metabolic bone disorder, leads to increased fracture risk and significant morbidity, particularly in postmenopausal women and the elderly. Traditional treatments often fail to fully restore bone health and may cause side effects, prompting the exploration of regenerative therapies. Adipose-derived stem cells (ADSCs) offer potential for osteoporosis treatment, but their natural inclination toward adipogenic rather than osteogenic differentiation poses a challenge. This study investigates a novel approach combining differentiation inducers (DIs), three-dimensional (3D) hydrogel scaffolds, and photobiomodulation (PBM) to promote osteogenic differentiation of immortalised ADSCs. A dextran-based 3D hydrogel matrix, supplemented with a DI cocktail of dexamethasone, β-glycerophosphate disodium, and ascorbic acid, was used to foster osteogenesis. PBM was applied using near-infrared (825 nm), green (525 nm), and combined wavelengths at fluences of 3 J/cm2, 5 J/cm2, and 7 J/cm2 to enhance osteogenic potential. Flow cytometry identified osteoblast-specific markers, while inverted light microscopy evaluated cellular morphology. Reactive oxygen species assays measured oxidative stress, and quantitative polymerase chain reaction (qPCR) revealed upregulated gene expression linked to osteogenesis. The findings demonstrate that integrating DIs, 3D hydrogels, and PBM effectively drives osteogenic differentiation in immortalised ADSCs. The PBM enhanced osteogenic marker expression, induced morphological changes, and upregulated gene activity, presenting a promising framework for bone regeneration. Future research should assess the stability and functionality of these differentiated cells and explore their applicability in preclinical models of bone injury or degeneration. This integrative approach demonstrated specific efficacy in promoting the osteogenic differentiation of ADSCs, highlighting its potential application in developing targeted treatments for osteoporosis.

Ensuring adequate bone health is crucial for preventing conditions such as osteoporosis and fractures. Zingerone, a phytonutrient isolated from cooked ginger, has gained attention for its potential benefits in bone health. This study evaluated the osteoprotective potential of zingerone and its effects on differentiation and signalling pathways in vitro using SAOS-2 osteosarcoma and RAW264.7 macrophage cell lines, aiming to elucidate its mechanism of action in bone remodelling.

SAOS-2 osteosarcoma and RAW264.7 macrophage cells were treated with zingerone at concentrations of 200 µM. Osteoblast differentiation was assessed by alkaline phosphatase (ALP) activity, bone mineralisation via Alizarin Red S stain, and gene expression markers (ALP, runt-related transcription factor 2 (Runx2), and osteocalcin) via quantitative polymerase chain reaction (q-PCR). Osteoclast differentiation was evaluated by tartrate-resistant acid phosphatase (TRAP) staining, TRAP activity, and mitogen-activated protein kinase (MAPK) pathways.

Treatment with zingerone was non-toxic at 200 µM. Zingerone (200 µM) significantly stimulated the gene expression of ALP and Runx2 in SAOS-2 cells (p < 0.05) without statistically significantly enhancing SAOS-2 mineralisation via calcium deposits. Moreover, zingerone significantly inhibited osteoclast differentiation in RAW264.7 cells as evidenced by reduced TRAP staining and activity (p < 0.05).

Zingerone shows promise in reducing osteoclast activity and supporting early osteoblast differentiation, suggesting its potential as a dietary supplement for bone health. Further in vivo and clinical studies are needed to confirm its role in managing osteoporosis.

Bone regeneration is a complex biological process that relies on the orchestrated interplay of various cellular and molecular events. Bone tissue engineering is currently the most promising method for treating bone regeneration. However, the immunogenicity, stable and cell quantity of seed cells limited their application. Recently, exosomes, which are small extracellular vesicles released by cells, have been found to effectively address these problems and better induce bone regeneration. Meanwhile, a growing line of research has shown the cargos of exosomes may provide effective therapeutic and biomarker tools for bone repair, including miRNA, lncRNA, and proteins. Moreover, engineered scaffolds loaded with exosomes can offer a cell-free bone repair strategy, addressing immunogenicity concerns and providing a more stable functional performance. Herein, we provide a comprehensive summary of the role played by scaffolds loaded with exosomes in bone regeneration, drawing on a systematic analysis of relevant literature available on PubMed, Scopus, and Google Scholar database.

Human osteocalcin (OC) undergoes reversible, vitamin K-dependent γ-carboxylation at three glutamic acid residues, modulating its release from bones and its hormonal roles. A complete understanding of OC roles and structure-activity relationships is still lacking, as only uncarboxylated and few differently carboxylated variants have been considered so far. To fill this lack of knowledge, a comprehensive experimental and computational investigation of the structural properties and calcium-binding activity of all the OC variants is reported here. Such a comparative study indicates that the carboxylation sites are not equivalent and differently affect the OC structure and interaction with calcium, properties that are relevant for the modulation of OC functions. This study also discloses cooperative effects and provides structural and mechanistic interpretation. The disclosed peculiar features of each carboxylated proteoform strongly suggest that considering all eight possible OC variants in future studies may help rationalize some of the conflicting hypotheses observed in the literature.

Human dental follicle cells (DFCs) as multipotent stem cells are currently investigated within the field of regenerative medicine considering their potential for the regeneration of dental tissues, bone defects caused by periodontal or degenerative diseases and the treatment of craniofacial disorders. However, molecular mechanisms of the differentiation into mineralizing cells are still inadequately understood. Previous studies have shown that GÖ6976, an inhibitor of classical isoforms of protein kinase C (PKC), enhanced ostogenic differentiation of DFCs. A possible mechanism for increased osteogenic differentiation could be the regulation of ossification inhibitors. This study therefore investigated whether the osteogenic differentiation inhibitor sclerostin (SOST) is regulated by GÖ6976 and whether the addition of sclerostin attenuates the stimulating effect of the PKC inhibitor. We demonstrated that the expression of the sclerostin gene decreased after PKC inhibition by GÖ6976 and that its gene expression is likely maintained by PKC via the BMP signaling pathway. Furthermore, supplementation of osteogenic differentiation medium with sclerostin impairs GÖ6976-induced differentiation of DFCs. Our data suggest that regulation of sclerostin mediates PKC inhibition-induced mineralization of DFCs.

This review investigates the therapeutic effects of Ulmus species extracts, traditionally used as tea ingredients in East Asia, on bone health and inflammatory conditions. Through the analysis of 9757 studies, narrowing down to 56 pertinent ones, we evaluated the safety and efficacy of Ulmus extracts. The focus was on catechin glycosides (CG) and flavonoid glycosides (FG), key compounds identified for their potential benefits. The research highlights the extracts' role in enhancing bone mineral density (BMD) by stimulating osteoblast activity and suppressing osteoclast differentiation, suggesting a protective effect against osteoporosis. Furthermore, the extracts demonstrated significant anti-inflammatory properties by modulating inflammatory markers and pathways. The findings confirm the historical use of Ulmus extracts in East Asia for health benefits and recommend further exploration into functional foods and nutraceuticals. The review calls for more rigorous research, including clinical trials, to establish optimal use and integration into modern health solutions. It underscores the potential of Ulmus extracts in promoting bone health and managing inflammation, advocating for a bridge between traditional practices and contemporary scientific validation. In conclusion, Ulmus extracts, a material long consumed as tea ingredients in East Asia, exhibit significant potential for improving bone health and reducing inflammation. This review calls for additional research to explore their full therapeutic capabilities, emphasizing the need for optimized extraction methods and clinical trials. It reinforces the importance of bridging traditional knowledge with contemporary scientific approaches to health and dietary solutions, promoting overall wellness.

Processing of bone allografts with strong acids and γ-sterilization results in decreased biomechanical properties and reduction in osteogenecity and osteoconductivity. High hydrostatic pressure (HHP) treatment could be a gentle alternative to processing techniques usually applied. HHP is known to induce devitalization of cancellous bone while preserving biomechanical stability and molecules that induce cell differentiation. Here, a specific HHP protocol for devitalization of cancellous bone was applied to rabbit femoral bone. Allogeneic bone cylinders were subsequently implanted into a defect in the lateral condyles of rabbit femora and were compared to autologous bone grafts. Analysis of bone integration 4 and 12 weeks postoperatively revealed no differences between autografts and HHP-treated allografts regarding the expression of genes characteristic for bone remodeling, showing expression niveous comparable to original bone cylinder. Furthermore, biomechanical properties were evaluated 12 weeks postoperatively. Autografts and HHP-treated allografts both showed a yield strength ranging between 2 and 2.5 MPa and an average bone mass density of 250 mg/cm2. Furthermore, histological analysis of the region of interest revealed a rate of 5 to 10% BPM-2 and approximately 40% osteocalcin-positive staining, with no marked differences between allografts and autografts demonstrating comparable matrix deposition in the graft region. A suitable graft integrity was pointed out by μCT imaging in both groups, supporting the biomechanical data. In summary, the integrity of HHP-treated cancellous bone allografts showed similar results to untreated autografts. Hence, HHP treatment may represent a gentle and effective alternative to existing processing techniques for bone allografts.

Human mesenchymal stromal cells (hMSCs), whether used alone or together with three-dimensional scaffolds, are the best-studied postnatal stem cells in regenerative medicine. In this study, innovative composite scaffolds consisting of a core-shell architecture were seeded with bone-marrow-derived hMSCs (BM-hMSCs) and tested for their biocompatibility and remarkable capacity to promote and support bone regeneration and mineralization. The scaffolds were prepared by grafting three different amounts of gelatin-chitosan (CH) hydrogel into a 3D-printed polylactic acid (PLA) core (PLA-CH), and the mechanical and degradation properties were analyzed. The BM-hMSCs were cultured in the scaffolds with the presence of growth medium (GM) or osteogenic medium (OM) with differentiation stimuli in combination with fetal bovine serum (FBS) or human platelet lysate (hPL). The primary objective was to determine the viability, proliferation, morphology, and spreading capacity of BM-hMSCs within the scaffolds, thereby confirming their biocompatibility. Secondly, the BM-hMSCs were shown to differentiate into osteoblasts and to facilitate scaffold mineralization. This was evinced by a positive Von Kossa result, the modulation of differentiation markers (osteocalcin and osteopontin), an expression of a marker of extracellular matrix remodeling (bone morphogenetic protein-2), and collagen I. The results of the energy-dispersive X-ray analysis (EDS) clearly demonstrate the presence of calcium and phosphorus in the samples that were incubated in OM, in the presence of FBS and hPL, but not in GM. The chemical distribution maps of calcium and phosphorus indicate that these elements are co-localized in the same areas of the sections, demonstrating the formation of hydroxyapatite. In conclusion, our findings show that the combination of BM-hMSCs and PLA-CH, regardless of the amount of hydrogel content, in the presence of differentiation stimuli, can provide a construct with enhanced osteogenicity for clinically relevant bone regeneration.

Bone is remodeled through a dynamic process facilitated by biophysical cues that support cellular signaling. In healthy bone, signaling pathways are regulated by cells and the extracellular matrix and transmitted via electrical synapses. To this end, combining electrical stimulation (ES) with conductive scaffolding is a promising approach for repairing damaged bone tissue. Therefore, "smart" biomaterials that can provide multifunctionality and facilitate the transfer of electrical cues directly to cells have become increasingly more studied in bone tissue engineering. Herein, 3D-printed electrically conductive composite scaffolds consisting of demineralized bone matrix (DBM) and polycaprolactone (PCL), in combination with ES, for bone regeneration were evaluated for the first time. The conductive composite scaffolds were fabricated and characterized by evaluating mechanical, surface, and electrical properties. The DBM/PCL composites exhibited a higher compressive modulus (107.2 MPa) than that of pristine PCL (62.02 MPa), as well as improved surface properties (i.e., roughness). Scaffold electrical properties were also tuned, with sheet resistance values as low as 4.77 × 105 Ω/sq for our experimental coating of the highest dilution (i.e., 20%). Furthermore, the biocompatibility and osteogenic potential of the conductive composite scaffolds were tested using human mesenchymal stromal cells (hMSCs) both with and without exogenous ES (100 mV/mm for 5 min/day four times/week). In conjunction with ES, the osteogenic differentiation of hMSCs grown on conductive DBM/PCL composite scaffolds was significantly enhanced when compared to those cultured on PCL-only and nonconductive DBM/PCL control scaffolds, as determined through xylenol orange mineral staining and osteogenic protein analysis. Overall, these promising results suggest the potential of this approach for the development of biomimetic hybrid scaffolds for bone tissue engineering applications.

The natural healing process of extraction socket and traditional socket plug material could not prevent buccal bone wall resorption and down growth of epithelium from the socket orifice. A multiphase bioactive socket plug (BP) is designed to overcome the natural healing process by maintaining the three-dimensional (3D) volume of extraction sockets, particularly in sockets with wall defects, and later provide sufficient alveolar bone volume for implant placement. The study aimed to fabricate and evaluate the physical, chemical, and biological performance of BPin vitro. The BP was fabricated through freeze-drying and layer-by-layer assembly, comprised of a base serving as a scaffold, a central portion for promoting bone regeneration, an upper buccal portion for maintaining alveolar socket dimension with a covering collagen membrane (Memb) on the top and upper buccal surface to prevent soft tissue infiltration. The BP as the experimental group and a pure collagen plug (CP) as the control group were investigated and compared. Radiograph, scanning electron microscopy, and energy-dispersive spectroscopy mapping confirmed that the four-part BP was successfully assembled and fabricated. Swelling rate analysis indicated that BP, CP, and Memb reached swelling equilibrium within 1 hour. BP exhibited a high remaining weight percentage in collagenase solution (68.81 ± 2.21% on day 90) and sustained calcium ion release, reaching the maximum 0.13 ± 0.04 mmol l-1on day 14. In biological assays, BP exhibited excellent cell proliferation (The OD value increased from 0.02 on day 1 to 0.23 on day 21.). The BP group exhibited higher alkaline phosphatase activity and osteocalcin content than the CP group within 21 days. Memb and BP exhibited outstanding barrier function, as evidenced by Hematoxylin and eosin staining. In summary, the multiphase bioactive socket plug represents a promising scaffold for alveolar ridge preservation application.

Bone has traditionally been viewed in the context of its structural contribution to the human body. Foremost providing necessary support for mobility, its roles in supporting calcium homeostasis and blood cell production are often afterthoughts. Recent research has further shed light on the ever-multifaceted role of bone and its importance not only for structure, but also as a complex endocrine organ producing hormones responsible for the autoregulation of bone metabolism. Osteocalcin is one of the most important substances produced in bone tissue. Osteocalcin in circulation increases insulin secretion and sensitivity, lowers blood glucose, and decreases visceral adipose tissue. In males, it has also been shown to enhance testosterone production by the testes. Neuropeptide Y is produced by various cell types including osteocytes and osteoblasts, and there is evidence suggesting that peripheral NPY is important for regulation of bone formation. Hormonal disorders are often associated with abnormal levels of bone turnover markers. These include commonly used bone formation markers (bone alkaline phosphatase, osteocalcin, and procollagen I N-propeptide) and commonly used resorption markers (serum C-telopeptides of type I collagen, urinary N-telopeptides of type I collagen, and tartrate-resistant acid phosphatase type 5b). Bone, however, is not exclusively comprised of osseous tissue. Bone marrow adipose tissue, an endocrine organ often compared to visceral adipose tissue, is found between trabecula in the bone cortex. It secretes a diverse range of hormones, lipid species, cytokines, and other factors to exert diverse local and systemic effects.

Bone formation is a complex process regulated by a variety of pathways that are not yet fully understood. One of the proteins involved in multiple osteogenic pathways is TID (DNAJA3). The aim of this work was to study the association of TID with osteogenesis. Therefore, the expression profiles of the TID splice variants (TID-L, TID-I) and their protein products were analyzed during the proliferation and differentiation of bone marrow mesenchymal stromal cells (B-MSCs) into osteoblasts. As the reference, the hFOB1.19 cell line was used. The phenotype of B-MSCs was confirmed by the presence of CD73, CD90, and CD105 surface antigens on ~97% of cells. The osteoblast phenotype was confirmed by increased alkaline phosphatase activity, calcium deposition, and expression of ALPL and SPP1. The effect of silencing the TID gene on the expression of ALPL and SPP1 was also investigated. The TID proteins and the expression of TID splice variants were detected. After differentiation, the expression of TID-L and TID-I increased 5-fold and 3.7-fold, respectively, while their silencing resulted in increased expression of SPP1. Three days after transfection, the expression of SPP1 increased 7.6-fold and 5.6-fold in B-MSCs and differentiating cells, respectively. Our preliminary study demonstrated that the expression of TID-L and TID-I changes under differentiation of B-MSCs into osteoblasts and may influence the expression of SPP1. However, for better understanding the functional association of these results with the relevant osteogenic pathways, further studies are needed.

Natural polymer-based hydrogels have been widely applied in bone tissue engineering due to their excellent biocompatibility and outstanding ability of drug encapsulation. However, they have relatively weak mechanical properties and lack bioactivity. Hence, we developed a bioactive nanoparticle composite hydrogel by incorporating LAPONITE®, which is an osteo-inductive inorganic nanoparticle. The incorporation of the nanoparticle significantly enhanced its mechanical properties. In vitro evaluation indicated that the nanocomposite hydrogel could exhibit good biocompatibility. Besides, the nanocomposite hydrogel was proved to have excellent osteogenic ability with up-regulated expression of osteogenic markers such as type I collagen (COL-I), runt-related transcription factor-2 (Runx-2) and osteocalcin (OCN). Furthermore, the in vivo study confirmed that the composite nanocomposite hydrogel could significantly promote new bone formation, providing a prospective strategy for bone tissue regeneration.

Runx2 and osteocalcin have pivotal roles in bone homeostasis. Polymorphism of these two genes could alter the function of osteoblasts and consequently bone mineral density (BMD). Attempts to understand the relationship between these polymorphisms and BMD in postmenopausal women across a variety of populations have yielded inconsistent results. This meta-analysis seeks to define the relationship between these polymorphisms with BMD in postmenopausal women.

Eligible studies were identified from three electronic databases. Data were extracted from the eligible studies (4 studies on Runx2 and 6 studies on osteocalcin), and associations of Runx2 T > C and osteocalcin HindIII polymorphisms with BMD in postmenopausal women were assessed using standard difference in means (SDM) and 95% confidence intervals (CI) as statistical measures.

A significant difference in the lumbar spine (LS) BMD in postmenopausal women was observed between the TT and CC homozygotes for the Runx2 T > C (SDM = -0.445, p-value = 0.034). The mutant genotypes (CC) showed significantly lower LS BMD in comparison to wild type genotypes under recessive model of genetic analysis (TC + TT vs. CC: SDM = -0.451, p-value = 0.032). For osteocalcin, HindIII polymorphism, the mutant genotypes (HH) was associated with significantly higher BMD for both LS and femoral neck (FN) than the wild type (hh) homozygotes (SDM = 0.152, p-value = 0.008 and SDM = 0.139, p-value = 0.016 for LS and FN, respectively). There was no association between total hip (TH) BMD and the osteocalcin HindIII polymorphism.

Runx2 T > C and osteocalcin HindIII polymorphisms influence the level of BMD in postmenopausal women and may be used as predictive markers of osteoporosis.

Tissue-engineered implants for bone regeneration require consideration regarding their mineralization and vascularization capacity. Different geometries, such as biomimetic designs and lattices, can influence the mechanical properties and the vascularization capacity of bone-mimicking implants. Negative Embodied Sacrificial Template 3D (NEST3D) printing is a versatile technique across a wide range of materials that enables the production of bone-mimicking scaffolds. In this study, different scaffold motifs (logpile, Voronoi, and trabecular bone) were fabricated via NEST3D printing in polycaprolactone to determine the effect of geometrical design on stiffness (10.44 ± 6.71, 12.61 ± 5.71, and 25.93 ± 4.16 MPa, respectively) and vascularization. The same designs, in a polycaprolactone scaffold only, or when combined with gelatin methacryloyl, were then assessed for their ability to allow the infiltration of blood vessels in a chick chorioallantoic membrane (CAM) assay, a cost-effective and time-efficient in ovo assay to assess vascularization. Our findings showed that gelatin methacrylolyl alone did not allow new chorioallantoic membrane tissue or blood vessels to infiltrate within its structure. However, polycaprolactone on its own or when combined with gelatin methacrylolyl allowed tissue and vessel infiltration in all scaffold designs. The trabecular bone design showed the greatest mineralized matrix production over the three designs tested. This reinforces our hypothesis that both biomaterial choice and scaffold motifs are crucial components for a bone-mimicking scaffold.

Cobalt-doped monetite powders were synthesized by coprecipitation method under a cobalt nominal content between 2 and 20 mol % of total cation. Structural characterization of samples was performed by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. XRD results indicated that the Co-doped samples exhibited a monetite single-phase with the cell parameters and crystallite size dependent on the amount of substitutional element incorporated into the triclinic crystalline structure. Cell viability and adhesion assays using pre-osteoblastic cells showed there is no toxicity and the RTqPCR analysis showed significant differences in the expression for osteoblastic phenotype genes, showing a potential material for the bone regeneration.

This study investigated whether osteocalcin (OCN) is present in osteoblast precursors and its relationship with initial phases of alveolar process formation. Samples of maxillae of 16-, 18-, and 20-day-old rat embryos (E16, E18, and E20, respectively), and 05-, 10-, and 15-day-old postnatal rats (P05, P10, and P15, respectively) were fixed and embedded in paraffin or araldite. Immunohistochemistry for osterix (Osx), alkaline phosphatase (ALP), and OCN detection was performed and the number of immunolabelled cells was computed. Non-decalcified sections were subjected to the von Kossa method combined with immunohistochemistry for Osx or OCN detection. For OCN immunolocalization, samples were fixed in 0.5% glutaraldehyde/2% formaldehyde and embedded in LR White resin. The highest number of ALP- and OCN-immunolabelled cells was observed in dental follicle of E16 specimens, mainly in basal portions of dental alveolus. In corresponding regions, osteoblasts in differentiation adjacent to von Kossa-positive bone matrix exhibited Osx and OCN immunoreactivity. Ultrastructural analysis revealed OCN immunoreactive particles inside osteoblast in differentiation, and in bone matrix associated with collagen fibrils and within matrix vesicles, at early stages of alveolar process formation. Our results indicate that OCN plays a role in osteoblast differentiation and may regulate calcium/phosphate precipitation during early mineralization of the alveolar process.

Periodontal disease is common in both developed and developing countries and affects around 20-50% of the global population, especially in adolescents, adults and the elderly is a public health problem. ADMSCs have the advantage of regenerating damaged tissue with high quality. DDM in the form of slices can improve healing in the mandibular sockets of molar teeth. The combination of ADMSC-DDM is expected to accelerate bone regeneration.

To analyze the combination of ADMSCs-DDM at increasing bone marker expression in periodontitis rats.

This research is experimental with a randomized control group post-test-only design. A total of 50 male Wistar rats were divided into four groups: 1) normal group (K); 2) CP model (K + ); 3) CP model and treated with DDM scaffold therapy (K(s)); 4) CP model and treated with ADMSCs-DDM combination therapy (K(sc)). Making a CP model with injected LPS P. gingivalis into interproximal gingiva of the right first and second lower molars. The in vivo research stage was the implantation of the DDM scaffold and the ADMSCs-DDM combination in the rat periodontal pocket. Rats were euthanized on days 7, 14, and 28, and immunohistochemistry of STRO-1, RUNX-2, OSX, COL-I, and OCN was performed. DDM scaffolds are made in 10%, 50% and 100% concentrations for MTT testing. Statistical results were analyzed with Kruskal-Wallis and Mann-Whitney tests.

The results of the MTT scaffold DDM were significant in the 10%, 50%, and 100% dilution groups (p < 0.05). The results showed there was a substantial difference in the expression of STRO-1 between the study groups (p < 0.05). The (K(sc)) was significantly higher than the (K) in RUNX-2 expression (p < 0.05). OSX expression showed significant results between study groups (p < 0.05). The expression of OCN and COL-I showed a significant difference in all study groups on day 28, where the (K(sc)) was higher than the (K) (p < 0.05).

Administration of the ADMSCs-DDM combination can accelerate alveolar bone regeneration on day 28. There is a mechanism of alveolar bone regeneration through the STRO-1, RUNX-2, OSX, and the COL-I pathway in periodontitis models.

Hydrogels are three-dimensional (3D) water-swellable polymeric matrices that are used extensively in tissue engineering and drug delivery. Hydrogels can be conformed into any desirable shape using 3D bio-printing, making them suitable for personalized treatment. Among the different 3D bio-printing techniques, digital light processing (DLP)-based printing offers the advantage of quickly fabricating high resolution structures, reducing the chances of cell damage during the printing process. Here, we have used DLP to 3D bio-print biocompatible gelatin methacrylate (GelMA) scaffolds intended for bone repair. GelMA is biocompatible, biodegradable, has integrin binding motifs that promote cell adhesion, and can be crosslinked easily to form hydrogels. However, GelMA on its own is incapable of promoting bone repair and must be supplemented with pharmaceutical molecules or growth factors, which can be toxic or expensive. To overcome this limitation, we introduced zinc-based metal-organic framework (MOF) nanoparticles into GelMA that can promote osteogenic differentiation, providing safer and more affordable alternatives to traditional methods. Incorporation of this nanoparticle into GelMA hydrogel has demonstrated significant improvement across multiple aspects, including bio-printability, and favorable mechanical properties (showing a significant increase in the compressive modulus from 52.14 ± 19.42 kPa to 128.13 ± 19.46 kPa with the addition of ZIF-8 nanoparticles). The designed nanocomposite hydrogels can also sustain drug (vancomycin) release (maximum 87.52 ± 1.6% cumulative amount) and exhibit a remarkable ability to differentiate human adipose-derived mesenchymal stem cells toward the osteogenic lineage. Furthermore, the formulated MOF-integrated nanocomposite hydrogel offers the unique capability to coat metallic implants intended for bone healing. Overall, the remarkable printability and coating ability displayed by the nanocomposite hydrogel presents itself as a promising candidate for drug delivery, cell delivery and bone tissue engineering applications.

Bone has the fascinating ability to self-regenerate. However, under certain conditions, such as type 2 diabetes mellitus (T2DM), this ability is impaired. T2DM is a chronic metabolic disease known by the presence of elevated blood glucose levels that is associated with reduced bone regeneration capability, high fracture risk, and eventual non-union risk after a fracture. Several mechanical and biological factors relevant to bone regeneration have been shown to be affected in a diabetic environment. However, whether impaired bone regeneration in T2DM can be explained due to mechanical or biological alterations remains unknown. To elucidate the relevance of either one, the aim of this study was to investigate the relative contribution of T2DM-related alterations on either cellular activity or mechanical stimuli driving bone regeneration. A previously validated in silico computer modeling approach that was capable of explaining bone regeneration in uneventful conditions of healing was further developed to investigate bone regeneration in T2DM. Aspects analyzed included the presence of mesenchymal stromal cells (MSCs), cellular migration, proliferation, differentiation, apoptosis, and cellular mechanosensitivity. To further verify the computer model findings against in vivo data, an experimental setup was replicated, in which regeneration was compared in healthy and diabetic after a rat femur bone osteotomy stabilized with plate fixation. We found that mechanical alterations had little effect on the reduced bone regeneration in T2DM and that alterations in MSC proliferation, MSC migration, and osteoblast differentiation had the highest effect. In silico predictions of regenerated bone in T2DM matched qualitatively and quantitatively those from ex vivo μCT at 12 weeks post-surgery when reduced cellular activities reported in previous in vitro and in vivo studies were included in the model. The presented findings here could have clinical implications in the treatment of bone fractures in patients with T2DM. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Polymer microparticles possess great potential as functional building blocks for advanced bottom-up engineering of complex tissues. Tailoring the three-dimensional architectural features of culture substrates has been shown to induce osteogenesis in mesenchymal stem cells in vitro, but the molecular mechanisms underpinning this remain unclear. This study proposes a mechanism linking the activation of Hedgehog signalling to the osteoinductive effect of surface-engineered, topographically-textured polymeric microparticles. In this study, mesenchymal progenitor C3H10T1/2 cells were cultured on smooth and dimpled poly(D,l-lactide) microparticles to assess differences in viability, cellular morphology, proliferation, and expression of a range of Hedgehog signalling components and osteogenesis-related genes. Dimpled microparticles induced osteogenesis and activated the Hedgehog signalling pathway relative to smooth microparticles and 2D-cultured controls without the addition of exogenous biochemical factors. We observed upregulation of the osteogenesis markers Runt-related transcription factor2 (Runx2) and bone gamma-carboxyglutamate protein 2 (Bglap2), as well as the Hedgehog signalling components, glioma associated oncogene homolog 1 (Gli1), Patched1 (Ptch1), and Smoothened (Smo). Treatment with the Smo antagonist KAAD-cyclopamine confirmed the involvement of Smo in Gli1 target gene activation, with a significant reduction in the expression of Gli1, Runx2 and Bglap2 (p ≤ 0.001) following KAAD-cyclopamine treatment. Overall, our study demonstrates the role of the topographical microenvironment in the modulation of Hedgehog signalling, highlighting the potential for tailoring substrate topographical design to offer cell-instructive 3D microenvironments. Topographically-textured microparticles allow the modulation of Hedgehog signalling in vitro without adding exogenous biochemical agonists, thereby eliminating potential confounding artefacts in high-throughput drug screening applications.

It is now widely recognized that mesenchymal stem cells (MSCs) possess the capacity to differentiate into a wide array of cell types. Numerous studies have identified the role of lncRNA in the regulation of MSC differentiation. It is important to elucidate the role and interplay of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in the regulation of signalling pathways that govern MSC function. Furthermore, miRNAs and lncRNAs are important clinical for innovative strategies aimed at addressing a wide spectrum of existing and emerging disease. Hence it is important to consider their impact on MSC function and differentiation. Examining the data available in public databases, we have collected the literature containing the latest discoveries pertaining to human stem cells and their potential in both fundamental research and clinical applications. Furthermore, we have compiled completed clinical studies that revolve around the application of MSCs, shedding light on the opportunities presented by harnessing the regulatory potential of miRNAs and lncRNAs. This exploration of the therapeutic possibilities offered by miRNAs and lncRNAs within MSCs unveils exciting prospects for the development of precision therapies and personalized treatment approaches. Ultimately, these advancements promise to augment the efficacy of regenerative strategies and produce positive outcomes for patients. As research in this field continues to evolve, it is imperative to explore and exploit the vast potential of miRNAs and lncRNAs as therapeutic agents. The findings provide a solid basis for ongoing investigations, fuelling the quest to fully unlock the regenerative potential of MSCs.