Search Results (452)

Imaging techniques have revolutionized cultural heritage analysis, particularly for objects that cannot be sampled. This study investigated the utilization of spectral imaging for the identification of pigments in artifacts from the Arxiu Valencià del Disseny, in conjunction with other portable spectroscopy techniques such as XRF, Raman, FT-NIR, and FT-MIR. Four early 1930s watercolors were examined using point-wise elemental and molecular spectroscopic data for pigment classification. Initially, the data cubes obtained with the spectral camera were processed using various methods. The spectral behavior was analyzed pixel-point, and the reflectance curves were qualitatively compared with a set of standards. Subsequently, a computational approach was applied to the data cube to produce RGB, false-color infrared (IRFC), and principal component (PC) images. Algorithms, such as the Vector Angle (VA) mapper, were also employed to map the pigment spectra. Consequently, 19th-century pigments such as Prussian blue, chrome yellow, and alizarin red were distinguished according to their composition, combining the spatial and spectral dimensions of the data. Elemental analysis and infrared spectroscopy supported these findings. In this context, the use of reflectance imaging spectroscopy (RIS), despite its technical limitations, emerged as an essential tool for the documentation and conservation of design heritage. Full article

Osteolforte, a compound with potential bone-regenerative properties, was investigated for its effects on human bone marrow stromal cells (hBMSCs). This study aimed to evaluate its impact on cell viability, osteogenic differentiation, and both gene and protein expression using a combination of assays, including CCK-8, Alizarin Red S staining, Quantitative Real-Time PCR (qRT-PCR), and Western blot analysis. The results demonstrated that Osteolforte significantly enhanced osteogenic differentiation in hBMSCs. Alizarin Red S staining revealed increased mineralization, indicating elevated calcium deposition. Gene expression analysis showed an upregulation of key osteogenic markers, including runt-related transcription factor-2 (RUNX-2), collagen type I (COL-1), and bone morphogenetic protein-2 (BMP-2), supporting the role of Osteolforte in promoting osteoblastic activity. In particular, the elevated expression of RUNX-2—a master transcription factor in osteoblast differentiation along with COL-1, a major bone matrix component, and BMP-2, a key bone morphogenetic protein—highlights the compound’s osteogenic potential. In conclusion, Osteolforte enhances early-stage osteogenesis and mineralization in hBMSCs and represents a promising candidate for bone regeneration. Full article

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

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

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

The present investigation was conducted to observe the effects of different energy densities of a low-level red laser (LLRL) on human embryonic stem cell-derived mesenchymal stem cells (hESC-MSCs). hESC-MSCs were cultured and irradiated with a LLRL from 0.5 to 5.0 J/cm² at a wavelength of 635 nm. Biological parameters such as proliferation, viability, and migration were observed after 72 h of LLRL irradiation. Compared with the control, LLRL irradiation significantly increased the proliferation and viability of hESC-MSCs from 0.5 to 2.5 J/cm² (p < 0.001, p < 0.05). LLRL irradiation from 0.5 to 3.0 J/cm² significantly increased the migration of hESC-MSCs (p < 0.01). These results revealed that LLRL irradiation at lower energy densities significantly increased the proliferation, viability, and migration of hESC-MSCs. However, higher energy densities were ineffective; this was also true when we examined osteogenic differentiation, as low energy densities of LLRL had a positive effect on differentiation, whereas higher energy densities had a negative effect on alkaline phosphatase activity, Alizarin Red staining and gene expression analysis. In addition, not all stem cell markers were affected by the laser, and a slight decrease in the expression of CD146, which is a stemness marker, was detected, indicating improved differentiation. These findings indicate that low energy densities of LLRL irradiation have positive effects on the proliferation, migration, and differentiation of hESC-MSCs. However, higher energy densities showed inhibitory effects. Full article

Background: Reconstructing maxillofacial defects is important in dentistry, so efforts are being made to develop materials that promote cell migration and repair. Graphene oxide (GO) is used to enhance the biocompatibility of polymethylmethacrylate (PMMA) due to its nanostructure. Objective: to assess cytotoxicity, cell proliferation, and differentiation of human dental pulp stem cells (hDPSC) in response to a conventional PMMA (PMMA) and polymer enriched with GO (PMMA+GO). Methods: Experiments were carried out with primary hDPSC subcultures. The PMMA and PMMA+GO were tested in direct and indirect contact. Cytotoxicity (1 day) and proliferation (3, 7, and 14 days) were evaluated with an MTT bioassay. The osteogenic, adipogenic, and chondrogenic aspects were determinate with alizarin red, oil red, and safranine. Mean values, standard deviation, and percentages were calculated; data were analyzed with Shapiro–Wilks normality and Student’s t-test. Results: The cell viability of PMMA and PMMA+GO in direct contact correspond to 90.8 ± 6.2, 149.6 ± 14.5 (1 day); 99.9 ± 7.0, 95.7 ± 6.1 (3 days); 120.2 ± 14.6, 172.9 ± 16.2 (7 days); and 102.9 ± 17.3, 95.4 ± 22.8 (14 days). For indirect contact, 77.2 ± 8.4, 99 ± 21.4 (1 day); 64.8 ± 21.6, 67.0 ± 9.6 (3 days); 91.4 ± 16.5, 142 ± 18.7 (7 days); and 63 ± 15.8, 79.1 ± 3.1 (14 days). PMMA+GO samples showed enhanced adipogenic, chondrogenic, and osteogenic aspects. Conclusions: The integration of GO into PMMA biopolymers stimulates cell proliferation and differentiation, holding great promise for future applications in the field of biomedicine. Full article

The tissue regenerative potential of the liquid component of mesenchymal stem cells has gained significant attention. Stem cells from human exfoliated deciduous teeth-conditioned medium (SHED-CM), which is often extracted during orthodontic treatment, promotes bone regeneration. However, further investigation is warranted to determine which component of SHED-CM affects bone regeneration. Therefore, we focused on the extracellular vesicles contained in SHED-CM (SHED-EVs) and aimed to study their effects on osteoblasts. SHED-EVs were isolated using a pellet-down EV extraction kit and identified using transmission electron microscopy and NanoSight. SHED-EVs were added to human calvarial osteoblasts (HCOs), and cell proliferation and migration ability were examined with Incucyte^® and BrdU. Alkaline phosphatase (ALP) expression was confirmed using real-time PCR and ALP quantification. The bone differentiation potential was examined using Alizarin Red S (ARS) staining. SHED-EVs promoted proliferation and migration of HCOs. Real-time PCR and ALP quantification results demonstrated that HCOs cultured with SHED-EVs exhibited increased ALP expression. ARS staining revealed that SHED-EVs promoted bone differentiation of HCOs. These results suggest that SHED-EVs promote cell proliferation and migration and bone regeneration of osteoblasts, highlighting their potential in the development of bone regeneration therapies. Full article

Background: The dentin–pulp complex plays a vital role in tooth health. Dentin forms the main body the tooth and continues to form throughout life to maintain homeostasis and provide protection against deleterious external stimuli. However, the detailed mechanism of dentin formation remains poorly understood, and there is a need for new regenerative therapies. This study therefore investigated whether primary dental pulp cells from mice could be used to establish a new culture system. Methods: Mouse mandibles were divided along the ramus to extract dental pulp tissue containing cervical loops. The extracted tissue was cultured in an incubator to promote cell out-growth and increase the number of cells available for experimentation. Results: Cultured cells formed mineralized nodules, confirmed by Alizarin red S staining. The expression levels of dentin sialo protein, bone gamma-carboxyglutamate protein, and type I collagen mRNAs in cultured dental pulp cells on day 15 were lower than those in intact mouse dental pulp tissue, and the expression of all mRNAs was confirmed through electrophoresis. Conclusions: This study established a primary culture system using dental pulp tissue extracted from mouse mandibular incisors. The results demonstrated that dental pulp cells can differentiate into odontoblast-like cells and form dentin-like mineralized nodules, thereby offering a useful system for studying dentin formation and odontoblast differentiation. Full article

This study aimed to investigate the effects of shear stress on osteogenic differentiation of human dental pulp stem cells (hDPSCs). The hDPSCs were subjected to shear stress for 24 h before osteogenic induction for 21 days. The mRNA expression of osteogenic markers such as RUNX2, OSX, ALP, COL1A1, OCN, and OPN was evaluated by real-time RT-PCR. Alkaline Phosphatase (ALP) activity and Alizarin Red S (ARS) staining were investigated to confirm osteogenic differentiation and mineralization of hDPSCs, respectively. The protein expression of osterix was shown by immunofluorescence staining and Western blotting. RNA sequencing was performed to investigate how shear stress affects the osteogenic differentiation of hDPSCs, which was validated through p38 inhibitor (SB203580) treatment. Real-time RT-PCR revealed that shear stress enhanced osteogenic marker-gene expression. The increased osterix protein expression was detected on Day 14 in the shear-stress loading group compared to the static group. Shear stress enhanced ALP activity and mineralization, observed on Days 14 and 21. A volcano plot exhibited up- and downregulated genes, while the p38 inhibitor markedly inhibited osteogenic differentiation of hDPSCs triggered by shear stress. In conclusion, shear stress promotes the osteogenic differentiation of hDPSCs through the p38 mitogen-activated protein kinase signaling pathway. Full article

In this study, a graphene oxide (GO)/zinc oxide (ZnO)/hydroxyapatite (nHAp) composite coating was constructed on a pure titanium surface by microarc oxidation (MAO) pretreatment combined with hydrothermal technology (HT), thereby making it possible to explore the performance optimization of this coating for Ti-based implants. Scanning electron microscopy (SEM), an energy dispersion spectrometer (EDS), Fourier transform infrared spectroscopy (FTIR), Ramam spectroscopy (Ramam), etc., confirmed that the GO/ZnO/nHAp composites were successfully loaded onto the pure Ti surfaces. Through nanoindentation, differential thermal analysis (DiamondTG/DTA), and dynamic polarization potential detection, the GO/ZnO/nHAp composite coating imparts excellent nanohardness (2.7 + 1.0 GPa), elastic modulus (53.5 + 1.0 GPa), thermal stability, and corrosion resistance to pure Ti implants; hemolysis rate analysis, CCK-8, alkaline phosphatase (ALP) detection, alizarin red staining, and other experiments further show that the coating improves the hemocompatibility, biocompatibility, and bone guidance of the Ti implant surface. Studies have shown that GO/ZnO/nHAp composite coatings can effectively optimize the mechanical properties, corrosion resistance, biocompatibility, and bone guidance of pure Ti implants, so that they can obtain an elastic modulus that matches human bone. Full article

Background and Objectives: Demineralized bone matrix (DBM) is a widely used bone graft substitute due to its osteoconductive and osteoinductive properties. However, its efficacy varies due to differences in donor, processing, and storage conditions. Synthetic alternatives, such as iFactor^®, combine non-organic bone mineral and a small peptide (P-15) to enhance the cellular attachment and osteogenesis. To compare the osteogenic potential and bone matrix maturity of iFactor^® and a commercial DBM scaffold through calcium nodule formation and Fourier transform infrared spectroscopy (FTIR) analysis. Materials and Methods: Human mesenchymal stem cells (hMSCs) were cultured and exposed to iFactor^® or DBM in paracrine culture conditions for 21 days. Calcium nodule formation was assessed using alizarin red staining and quantified spectrophotometrically. The FTIR analysis of hMSCs exposed to the scaffolds for three months evaluated the biomolecular composition and bone matrix maturity. Results: Calcium nodules formed in both groups but in smaller quantities than in the positive control (p < 0.05). The biomolecular components of the DBM were similar to healthy bone (p > 0.05) than those of the iFactor^® group (p < 0.005). A different rate of bone regeneration was observed through the formation of a greater number of calcium nodule aggregates identified in the extracellular matrix of mesenchymal stem cell cultures exposed to iFactor^® compared to those cultures enriched with DBM. Conclusions: Both experimental matrices demonstrated similar osteogenic potential at the 3-month follow-up. Although DBM has a closer biomolecular composition and carbonate substitution compared to healthy bone, iFactor^® showed faster matrix maturity expressed through the formation of a greater number of calcium nodule aggregates and higher hMSCs proliferation. Full article

TGF-β is a multifunctional pathway that controls significant cellular and physiological processes and several pathological activities. TGF-β-induced signaling can be triggered upon binding to specific receptors to initiate the transcriptional activation of several genes and cellular processes. However, the detailed role of TGF-β signaling in osteoblast differentiation remains to be explicated. SB525334, a selective TGF-βRI inhibitor, was investigated for its effect on the osteoblastic differentiation of human bone marrow MSCs at different concentrations. Alkaline phosphatase (ALP) activity was used to assess osteoblast differentiation marker, while Alizarin red staining was used as a marker for mineralization. Expressions of osteoblast-specific genes were evaluated using real-time PCR. A migration assay was performed to assess the effect of TGF-β on wound healing. Moreover, immunofluorescent staining for SMAD2/3 and SMAD4 was employed to confirm the activation of the TGF-β pathway. The inhibition of TGF-β1 signaling using a high concentration of SB525334 (3 µM) significantly reduced ALP activity and mineralization and downregulated osteoblast-specific genes. However, the opposite effect was reported using a lower concentration (0.03 µM), where osteoblast-associated genes were significantly upregulated, and ALP activity and mineralization were higher. Significant scratch/wound healing was achieved at a lower concentration of SB525334, while a higher concentration of SB525334 resulted in lower healing. Moreover, a low concentration of SB525334 demonstrated nuclear translocation of SMAD 2/3 and 4. Our study confirms that the effect of TGF-β signaling in bone formation and wound healing is dose-dependent, and the use of TGF-β is recommended as a valuable therapeutic approach. Full article

Background and Objectives: Dexamethasone has been widely researched for its ability to promote osteogenic differentiation in mesenchymal stem cells in basic research. This study focused on examining the effects of dexamethasone on both cell viability and osteogenic differentiation in three-dimensional stem cell spheroids. Materials and Methods: These spheroids were created using concave microwells and exposed to dexamethasone at concentrations ranging from 0 μM to 100 μM, including intermediate levels of 0.1 μM, 1 μM, and 10 μM. Microscopic analysis was used to qualitatively assess cellular viability, while a water-soluble tetrazolium salt-based assay provided quantitative viability data. Osteogenic differentiation was evaluated by measuring alkaline phosphatase activity and calcium deposition using Alizarin Red staining. Additionally, the expression levels of genes associated with osteogenesis were measured through quantitative polymerase chain reaction. Results: The spheroids successfully self-assembled within the first 24 h and maintained their structural integrity over a seven-day period. Analysis of cell viability showed no statistically significant differences across the various dexamethasone concentrations tested. Although there was an observed increase in alkaline phosphatase activity and calcium deposition following dexamethasone treatment, these differences were not statistically significant. RUNX2 gene expression was upregulated in the 1 μM, 10 μM, and 100 μM groups, while COL1A1 expression significantly increased at 0.1 μM and 1 μM. Conclusions: These results indicate that dexamethasone supports cell viability and enhances RUNX2 and COL1A1 expression in stem cell spheroids. Full article

The unique properties of lanthanum oxide nanoparticles (La₂O₃NPs) make them highly suitable for various environmental applications. This study explores the plant-based synthesis of La₂O₃NPs using Drypetes sepiaria as a reducing agent. The synthesized La₂O₃NPs were characterized through a range of spectroscopic and microscopic techniques. Scanning electron microscopy (SEM) revealed that the La₂O₃NPs have an uneven surface and a stony appearance. A morphological analysis indicated that the nanoparticles range in size from 20 to 50 nm. The appreciable band gap energy values were concluded as 5.5 eV. The crystal structure and elemental composition were determined using X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS). The results from the microplate assay method demonstrated enhanced anti-biofilm properties, and photocatalytic tests showed significant dye-degradation capabilities. The degradation efficiency and zone inhibition values of the La₂O₃NPs were found to be 90.12% and 39.18%, respectively. Full article