Search Results (139)

The aim of the study was to investigate the synergistic effect of conditioned medium (CM) and two types of calcium phosphate biocements on the osteogenic properties of a composite material through rat bone marrow-derived mesenchymal stem cells (MSCs). Briefly, MSCs were cultured for 7 and 17 days in extracts derived from the two biocement types. These extracts were supplemented with 5% (v/v) of concentrated CM. The CM was obtained from rat bone marrow MSC cultures after a 48 h conditioning period. The results showed that the addition of CM had a significant positive impact on the osteoblastic differentiation of MSCs, particularly in the extracts from the tetracalcium phosphate/monetite/calcium sulfate hemihydrate biocement (designated as CAS cement) compared to the other tested cement extract (designated C cement). After 17 days of culturing, a notable increase in cell viability and alkaline phosphatase (ALP) activity, as well as the upregulation of osteoblastic-related gene expression, was found. This enhancement in osteogenic activity was likely driven by the growth factors and bioactive molecules present in the CM. The study concluded that supplementing the biocement extracts with only 5% of 10X concentrated CM is sufficient to significantly influence and improve the in vitro characteristics, cell behavior, gene expression, and synthesis of cell products. It was demonstrated that, especially in the CAS supplemented with CM (CAS + CM) extract system, the improvement in osteogenic properties was due to the synergistic effect between the higher concentration of calcium ions in extracts released from the calcium sulfate hemihydrate-containing cement and the bioactive molecules supplied by the CM. Full article

Background: Skeletal muscle laceration injuries remain a clinical challenge owing to limited and often delayed functional recovery. Surgical repair often fails to fully restore injured muscle, causing fibrosis and functional impairments. Mesenchymal stem cells (MSCs) represent a potential therapy due to their regenerative and immunomodulatory properties. However, their short-term regenerative effects in laceration injuries remain under-explored. Objective: We aim to evaluate the short-term effects of allogenic bone marrow-derived MSCs on skeletal muscle regeneration following laceration injury in rats. Methods: Sprague Dawley rats underwent laceration injury to the right gastrocnemius muscle and received local injection of either saline (n = 6) or allogeneic bone marrow-derived MSCs (2 × 10⁶ cells; n = 6) two weeks after injury. Muscle functional recovery was evaluated by measuring tetanic contraction force of the injured relative to the contralateral uninjured leg and compared among MSC-treated, saline-treated, untreated injured (n = 6), and intact control groups (n = 6) on days 7 and 14 post-treatment. Histological assessment of the treated muscle groups using Hematoxylin and Eosin and Masson’s Trichrome staining was conducted on day 7 post-treatment. Results: On day 7 post-treatment, MSC-treated muscle showed higher normalised force (96.8 ± 15.0%) than saline-treated (76.7 ± 4.6%) (p = 0.0393), but not untreated, muscle (83.1 ± 14.7%) (p = 0.2259). By day 14, the MSC-treated group exhibited significantly greater recovery of muscle force (110.8 ± 6.46%) than both the saline-treated (78.4 ± 6.47%) (p < 0.0001) and untreated groups (88.1 ± 3.41%) (p = 0.0001). Force recovery in the MSC-treated muscle was comparable to that in intact muscle (102.6 ± 10.4%) at both time points (p = 0.230). Supplementary histological analysis showed mild inflammatory cell infiltration, well-formed myoblasts, and a lower fibrosis index in MSC-treated muscle (29.30 ± 0.29%) compared with saline-treated muscle (31.77 ± 0.43%) (p < 0.0001) on day 7 post-treatment. Conclusions: Allogeneic bone marrow-derived MSC therapy is associated with enhanced repair of lacerated skeletal muscle over a short recovery period; however, larger studies with broader assessments are needed to confirm its potential clinical applicability. Full article

(1) Objective: This study aimed to investigate the synergistic effect and underlying mechanisms of Total Flavonoids of Rhizoma drynariae (TFRD) in combination with Bone Marrow Mesenchymal Stem Cells (BMSCs) in the repair of tendon–bone injuries. (2) Methods: The effects of TFRD on the proliferation and migration of BMSCs were assessed using CCK-8 and scratch assays, and its potential to promote osteogenic and chondrogenic differentiation was evaluated. Concurrently, the pro-angiogenic effect of TFRD on Human Umbilical Vein Endothelial Cells (HUVECs) was observed. In vivo, a rat model of Achilles tendon–bone injury was established and animals were divided into four groups: SHAM, Model, BMSCs, and BMSCs + TFRD. After an 8-week intervention, the level of functional recovery was evaluated through histological analysis, immunohistochemistry, serum biochemical analysis, and biomechanical testing. (3) Results: A concentration of 5.0 μg/mL TFRD significantly promoted the proliferation, migration, and differentiation of BMSCs and enhanced the tube formation capacity of HUVECs. In the BMSCs + TFRD group, histological analysis revealed well-organized collagen fibers, increased cartilage deposition, and an optimized tendon–bone interface (TBI) structure. Immunohistochemistry showed upregulated expression of COL I, COL II, and SOX-9, alongside downregulated VEGFA. Furthermore, serum IL-6 levels were decreased, while IL-10 and TGF-β levels were elevated. The biomechanical properties were also significantly improved in this group. (4) Conclusions: TFRD promotes tendon–bone healing and functional recovery by enhancing BMSC functions, promoting angiogenesis, and improving the local microenvironment. Full article

Graphene-based nanomaterials, including graphene oxide (GO) and graphene quantum dots (GQDs), exhibit exceptional properties, which might facilitate the functional modification of TiO₂ nanotubes (NTs) for enhanced rapid osseointegration. This study investigated the effects of GO/GQD-deposited TiO₂-NTs on cell proliferation, osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BMSCs), and early osseointegration in male 6-week-old Sprague Dawley (SD) rats. TiO₂-NTs (control group) were fabricated on titanium substrates via anodic oxidation. GO and GQDs were electrochemically deposited onto the TiO₂-NTs using cyclic voltammetry with 0.5 mg/mL GO and 0.1 mg/mL GQD dispersions to form NT-GO and NT-GQDs. In vitro assays evaluated cell adhesion, proliferation, and osteogenic differentiation. Implants were randomly inserted into one femoral epiphysis of nine rats (n = 3), and osseointegration was evaluated using micro-computed tomography and sequential fluorescence labeling at 2, 4, and 6 weeks post-implantation. Statistical analysis was conducted using ANOVA. Cyclic voltammetry successfully synthesized NT-GO and NT-GQDs, with Raman spectra confirming D and G bands. Both NT-GO and NT-GQDs exhibited superior cell adhesion, proliferation, and enhanced osteogenic differentiation compared with TiO₂-NTs. Notably, the NT-GQDs significantly promoted new bone formation in vivo. The integration of graphene nanomaterials onto TiO₂-NTs improves biocompatibility and accelerates osteogenesis, suggesting a promising strategy for enhancing osseointegration in orthopedic and dental implants. Full article

Background/Objectives: Osteoporosis is a prevalent and debilitating skeletal disease characterized by a progressive loss of bone mass and deterioration of bone microarchitecture. Probiotics have emerged as a potential therapeutic tool for treating osteoporosis through modulation of the gut microbiota. In this study, we aimed to examine the effects of live Lacticaseibacillus rhamnosus AC1 (LR-AC1), isolated from a fecal sample from a newborn in Hong Kong, on deoxycorticosterone acetate (DOCA)-induced bone loss in a rat model. Methods: Bone mass and microarchitecture were assessed using micro-computed tomography (micro-CT). Immunostaining for CD31⁺ and osterix, markers of endothelial cells and osteoblast precursors, respectively, was performed. Gut microbiota composition was analyzed via 16S rRNA sequencing. The effects of an LR-AC1 cell-free conditioned supernatant (CCS) on osteoclastogenesis, angiogenesis, and migration of bone marrow mesenchymal stem cells (BMSCs) were evaluated in vitro using RT-qPCR and wound healing assays. Results: LR-AC1 administration did not induce adverse effects in healthy rats; however, it exacerbated bone loss in rats with DOCA-salt-induced osteoporosis. Correspondingly, the number of CD31-positive endothelial cells and osterix-positive osteoprogenitors decreased with bone loss. In vitro, LR-AC1 CCS promoted osteoclastogenesis and angiogenesis, while in the presence of DOCA, LR-AC1 CCS inhibited BMSC migration. Gut microbiota analysis revealed that the relative abundances of the genera g_RF39 and g_Clostridia_UCG-014 correlated with the severity of bone loss. Conclusions: While several studies suggest that probiotics can prevent and treat osteoporosis, our findings indicate that in a male rat model of DOCA-salt-induced osteoporosis, live LR-AC1 aggravated bone loss. This effect is associated with alterations in gut microbiota and disruption of the coupling process in bone remodeling. Full article

Bone marrow aspirate concentrate (BMAC) is increasingly recognized as a valuable orthobiologic, offering promising outcomes in reducing inflammation, alleviating pain for patients with osteoarthritis (OA) and various musculoskeletal conditions. However, BMAC contains a very low percentage of mesenchymal stem cells (MSCs), and multiple injections are often required with multiple harvests, which can lead to scarring at the extraction site and patient discomfort. This study aimed to determine whether freezing BMAC affects the function of MSCs in vitro and their capacity to repair articular cartilage in vivo using an OA rat model. BMAC was obtained from patients undergoing BMAC treatment. The in vitro results showed that the proliferation and multilineage differentiation of MSCs remained similar after being frozen for 4 weeks at −80 °C. In vivo, both fresh and frozen BMAC demonstrated significantly improved ICRS histology score of tibial plateau cartilage compared to the PBS control. No significant difference was found between fresh and frozen BMAC treatment groups. Our results suggest that the freezing process does not negatively affect the function of MSCs from BMAC for cartilage repair. These findings support the potential future applications of a single harvest with BMAC storage for multiple injections, thereby enhancing the tissue repair capabilities of BMAC. Full article

Treatment for acute liver failure (ALF) is constrained by shortages of liver transplant donors and immune rejection. Porcine bone marrow mesenchymal stem cells (pBMSCs) demonstrate clinical potential in xenotransplantation due to their abundant availability, low immunogenicity, and strong proliferative activity. This study is the first to investigate the reparative effects and mechanisms of pBMSCs derived from Luopan Mountain pigs in a D-galactosamine (D-GalN)-induced ALF rat model. The results demonstrated that tail-vein transplantation of pBMSCs significantly improved survival rates in ALF rats; reduced serum ALT, AST, and TBIL levels; enhanced hepatic glycogen metabolism; and mitigated histopathological liver damage. Additionally, pBMSC transplantation upregulated serum HGF, IGF-1, and VEGF levels while inhibiting hepatocyte apoptosis. Mechanistic studies indicate that pBMSCs promote liver function recovery and regeneration by activating the PI3K/Akt/mTOR signaling pathway and suppressing its key negative regulator, PTEN, by regulating the expression of key genes involved in inflammation, fibrosis, proliferation, and apoptosis. This study provides crucial experimental evidence for the use of pBMSCs in treating acute liver failure (ALF) and lays the groundwork for its clinical translation in the field of xenotransplantation. Full article

Background/Objectives: Guided bone regeneration (GBR) requires barrier membrane materials that balance biodegradation with mechanical stability. Magnesium (Mg)-based metals have good prospects for use as biodegradable barrier materials due to their elastic modulus, good biocompatibility, and osteogenic properties. In this study, gallium (Ga) was introduced into Mg to enhance the mechanical strength and optimize the degradation behavior of the alloy, addressing the limitations of conventional magnesium alloys in corrosion control and strength retention. Methods: Mg-xGa alloys (x = 1.0–3.0%, wt.%) were evaluated for biocompatibility, degradation, and osteogenic potential. Corrosion rates were calculated via weight loss, Mg²⁺ release, and pH changes. Osteogenic effects were assessed using rat bone marrow mesenchymal stem cells (rBMSCs) for alkaline phosphatase (ALP) activity, extracellular matrix (ECM) mineralization, and osteogenic-related gene expression. Optimal alloy was fabricated into barrier membranes with different pore sizes (0.85–1.70 mm) for the rabbit mandibular defect to evaluate the porosity effect on new bone formation. Results: Cytocompatibility tests established a biosafety threshold for Ga content below 3 wt.%. Mg-1Ga demonstrated uniform corrosion with a rate of 1.02 mm/year over 28 days. In vitro, Mg-1Ga enhanced ALP activity, ECM mineralization, and osteogenic gene expression. The 1.70 mm pore size group exhibited superior new bone formation and bone mineral density at 4 and 8 weeks. Conclusions: These results highlight Mg-1Ga’s biocompatibility, controlled degradation, and osteogenic properties. Its optimized pore design bridges the gap between collagen membranes’ poor strength and titanium meshes’ non-degradability, offering a promising solution for GBR applications. Full article

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

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

Bone marrow stimulation is a treatment for articular cartilage injuries that promotes cartilage repair by inducing the migration and accumulation of mesenchymal stem cells (MSCs), but often results in fibrocartilage with limited durability. This study aimed to investigate the effect of hypoxic conditions on cartilage repair using a rat osteochondral defect model. Osteochondral defects (1.0 mm in diameter) were created in the femoral trochlear groove, and rats were exposed to hypoxic conditions (12% O₂) for 4 weeks postoperatively. Histological analysis was performed, and protein expression of hypoxia-inducible factor-1α (HIF-1α) and SRY-box transcription factor 9 (SOX9) in the repair tissue was evaluated after 1 week. As a result, after 1 week, protein expression of HIF-1α and SOX9 in the Hypoxia group was significantly increased compared to the Normoxia group. After 4 weeks, the Hypoxia group exhibited a hyaline cartilage-like tissue structure with a significantly lower Modified Wakitani score compared to the Normoxia group. Furthermore, after 4 weeks, the inhibition of HIF-1α suppressed cartilage repair. These findings suggest that hypoxic conditions promote SOX9 expression via HIF-1α during the early phase of MSC chondrogenic differentiation and promote the formation of hyaline cartilage-like repair tissue. In conclusion, bone marrow stimulation under hypoxic conditions may enhance the repair effect on articular cartilage injuries. Full article

Hydroxyapatite nanowires (HAW) can effectively improve the bone repair ability in bone engineered tissue. However, due to their single function, the application of HAWs in biological tissue engineering materials is limited. In this study, strontium-doped hydroxyapatite nanowires (SrHAW) were synthesized by a hydrothermal method and coated with polydopamine (PDA) to improve the function of HAWs. The material structure, biocompatibility evaluation, and differentiation capability testing of PDA-coated strontium-doped hydroxyapatite (SrHAW@PDA) nanowires were conducted. Then, the nanowires were co-cultured with rat bone marrow mesenchymal stem cells (BMSCs) and rat umbilical vein endothelial cells (UVECs) to prepare cell spheroids. Compared with the undoped and uncoated HAW, the SrHAW@PDA nanowires enhanced the cell activity and their angiogenesis and osteogenesis abilities. In addition, their performance in the three-dimensional spheroid also played a positive role in the cells in the spheroid. Due to the presence of PDA, the adhesion between the cells in the three-dimensional spheroid and the nanowires were enhanced. In summary, these results show that SrHAW@PDA has the potential to be used as an alternative material to regulate cell biological activity in three-dimensional cell spheroids. Full article

Objectives: The objective of this study is to compare the bone-regenerating capacity between chitosan foam and chitosan membrane scaffolds. Methods: A medium-weight chitosan acidic mixture was used to prepare two scaffolds of freeze-dried chitosan foam (CF). One of the two CF scaffolds was physically crosslinked by NaHCO₃ to obtain chitosan membrane (CM). A morphological assessment of the specimens’ porosity was carried out by scanning electron microscopy (SEM). An MTT assay of the CM and CF specimens using rats’ bone marrow mesenchymal stem cells (MSCs) was carried out. Then, 38 albino rats were subjected to surgical implantation in a critical-size defect of the femur bone. The rats were divided into three groups according to the type of implanted scaffold (Control (no scaffold) n = 10, CM (chitosan membrane) n = 14, CF (chitosan foam) n = 14). Each group was equally subdivided into two subgroups according to the time of euthanasia (21 d, 35 d). The femur bones were dissected for a histological analysis (hematoxylin and eosin, and Masson trichrome). The results of the histological analysis were graded according to a scoring system. A statistical analysis of the pore size and histological grading was carried out. Results: CF had a higher mean pore size (65.42 µm) compared to CM (6.44 µm); CM showed a significantly higher proliferation of MSCs at 72 h. Both the CM and CF groups showed a significantly higher bone regeneration and lower inflammation than the control group. The CF group showed a significantly higher bone regeneration score than the CM group, especially at 35 d with more dense compact lamellar bone structure. Conclusions: The higher mean pore size of CF allowed for a higher bone regenerating capacity than the crosslinked CM. Full article

Hierarchical porous hydrogels possess advantageous characteristics that facilitate cell adhesion, promote tissue growth, and enhance angiogenesis and osteogenesis. In this study, porous composite hydrogels were successfully prepared by a two-step gelation method with sodium alginate (SA), gelatin (GEL), and calcium hydrogen phosphate (DCP) as the main components. The fabricated porous hydrogels initially featured small pores (approximately 60 μm), and gradually evolved to large pores (exceeding 250 μm) during the gradual degradation in the cellular microenvironment. In vitro cell culture experiments indicated that these hydrogels could enhance the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells due to the hierarchical porous structure and the incorporation of DCP. Subcutaneous implantation and cranial defect repair experiments in Sprague−Dawley rats further confirmed that the small initial pore size of hydrogel scaffolds can provide more sites for cell adhesion. Additionally, the gradual degradation to form large pores was conducive to cell/tissue growth and blood vessel formation, ultimately being beneficial for vascularized bone regeneration. In summary, this study proposes an innovative strategy for developing porous hydrogels with gradual degradation for functional bone regeneration. Full article

Background: Osteoporosis is a global health problem that significantly decreases patients’ quality of life and causes tremendous medical burdens. Therefore, exploring effective targeting strategies for osteoporosis treatment is crucial. Previous studies have indicated that pleiotrophin (PTN) was a secretory factor involved in several biological processes, such as angiogenesis, neural development, and abnormal osteogenic functions in osteoporosis. However, the roles of PTN in osteogenics and the mechanisms remain unclear. Methods: In this study, we explored the effects and mechanisms of PTN in regulating osteogenic functions using real-time quantitative PCR, immunofluorescence, ALP detection, a TUNEL assay, RNA sequencing, and phosphorylation quantitative proteomics. Fracture-healing experiments in osteoporosis rats were also conducted to evaluate the osteogenic functions of PTN in vivo. Results: We found that PTN significantly inhibited apoptosis and promoted the osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs). Further experiments showed that PTN regulated the biological functions of rBMSCs by promoting antioxidant functions and reducing cellular reactive oxygen species (ROS), thereby protecting rBMSCs from accumulated ROS. Additionally, we found that PTN binds to the PTPRZ1 receptor, inducing intracellular PLCG1 phosphorylation and NCOA3 nuclear translocation, which regulate the downstream antioxidant functions of rBMSCs. Additionally, we verified that PTN effectively promoted fracture healing in osteoporotic animals. Conclusions: This study elucidates the mechanisms by which PTN promotes osteogenesis and verifies this effect in vivo, offering an effective target for osteoporosis treatment. Full article