Saos-2 Cells Research Articles

Small molecule inhibitors of IL-1R1/IL-1β interaction identified via transfer machine learning QSAR modelling

The human interleukin-1 receptor I (IL-1R1) is a cytokine receptor recognized by interleukin 1β (IL-1β), among other cytokines. Over activation of IL-1R1 has been implicated in various inflammatory conditions. This research aims to identify small-molecule inhibitors targeting the hIL1R1/IL1β interaction, employing a multi-task transfer learning approach for quantitative structure-activity relationship (QSAR) modelling. A comprehensive bioactivity dataset from functionally related proteins was utilised to build a robust ensemble machine learning model for predicting IC50 values against the target protein. Despite the availability of antibody-based therapies, the absence of orally available small-molecule inhibitors necessitates their development. By combining model predictions with docking and simulation approaches, the interleukin-1 receptor inhibitor (IRI-1) emerged as a lead compound. It potently inhibited human IL1-R1 with micromolar activity in THP-1 and Saos-2 cells and demonstrated good biocompatibility. Western blot analysis revealed that IRI-1 inhibits IL-1β-mediated phosphorylation of IL1-R1, JNK, IRAK-4, and ERK in THP-1 cells. Furthermore, molecular dynamics simulations confirmed the structural stability of the protein-ligand complexes. This study highlights the effectiveness of multi-task transfer learning approaches for building robust QSAR models against novel proteins or those with limited bioactivity data, such as hIL-1β/IL-1R1 protein.

Zibibbo Grape Seeds’ Polyphenolic Profile: Effects on Bone Turnover and Metabolism

Background: The consumption of seeds as food has become increasingly common due to their numerous health benefits. Among these, the seeds of the Zibibbo grape from Pantelleria, a native species of southern Italy, remain largely unexplored and are usually considered waste material from viticulture. Nevertheless, Zibibbo grape seeds may offer health benefits, particularly for the elderly and people with metabolic disorders, due to their potential content of beneficial compounds such as polyphenols. Methods: The Zibibbo grape seeds extract (ZSE) was characterized using UV-visible spectrophotometry and HPLC chromatography. The antioxidant activity of ZSE was measured by different colorimetric assays and Electronic Paramagnetic Resonance (EPR). Additionally, specific in vitro tests were conducted on human osteoblast cell lines (Saos-2 and MG63) aiming to evaluate the ZSE’s effects on bone turnover and metabolism. Western blotting was used to assess the impact on specific proteins and pathways related to bone health. Results: The ZSE contained almost ~3 mg/mL of carbohydrates and phenolic compounds, including rutin (~6.4 ppm) and hesperidin (~44.6 ppm). The extracts exhibited an antioxidant activity greater than 90% across all tests performed. Moreover, the Zibibbo seed extracts exerted a significant proliferative effect on the Saos-2 cell human osteoblast-like cell line, also modulating the phosphorylation of specific kinases involved in cell health and metabolism. Conclusions: Zibibbo grape seeds are rich in phenolic compounds, especially flavonoids with strong antioxidant and free radical scavenging properties. ZSE demonstrated beneficial effects on bone metabolism and osteoblast proliferation, suggesting potential for counteracting osteodegenerative conditions like osteoporosis. If confirmed through further studies, Zibibbo grape seed phenolic compounds could serve as an adjunctive therapy for osteoporosis, helping to slow aging and bone degeneration.

IMPC-based screening revealed that ROBO1 can regulate osteoporosis by inhibiting osteogenic differentiation.

The utilization of denosumab in treating osteoporosis highlights promising prospects for osteoporosis intervention guided by gene targets. While omics-based research into osteoporosis pathogenesis yields a plethora of potential gene targets for clinical transformation, identifying effective gene targets has posed challenges. We first queried the omics data of osteoporosis clinical samples on PubMed, used International Mouse Phenotyping Consortium (IMPC) to screen differentially expressed genes, and conducted preliminary functional verification of candidate genes in human Saos2 cells through osteogenic differentiation and mineralization experiments. We then selected the candidate genes with the most significant effects on osteogenic differentiation and further verified the osteogenic differentiation and mineralization functions in mouse 3T3-E1 and bone marrow mesenchymal stem cells (BMSC). Finally, we used RNA-seq to explore the regulation of osteogenesis by the target gene. We identified PPP2R2A, RRBP1, HSPB6, SLC22A15, ADAMTS4, ATP8B1, CTNNB1, ROBO1, and EFR3B, which may contribute to osteoporosis. ROBO1 was the most significant regulator of osteogenesis in both human and mouse osteoblast. The inhibitory effect of Robo1 knockdown on osteogenic differentiation may be related to the activation of inflammatory signaling pathways. Our study provides several novel molecular mechanisms involved in the pathogenesis of osteoporosis. ROBO1 is a potential target for osteoporosis intervention.

Fabrication and characterization of nanohydroxyapatite/chitosan/decellularized placenta scaffold for bone tissue engineering applications

Novel biomaterials are necessary to fabricate biomimetic scaffolds for bone tissue engineering. In the present experiment, we aimed to fabricate and evaluate the osteogenic properties of nanohydroxyapatite/chitosan/decellularized placenta (nHA.Cs.dPL) composite scaffolds. The human placenta was decellularized (dPL), characterized, and digested in pepsin to form the hydrogel. nHA.Cs.dPL scaffolds were fabricated using salt leaching/freeze drying and evaluated for their morphology, chemical composition, swelling, porosity, degradation, mechanical strength, and biocompatibility. Saos-2 cells were seeded on scaffolds, and their osteogenic properties were investigated by evaluating alkaline phosphatase (ALP), osteocalcin (OCN), collagen type 1 (COL I) expression, and calcium deposition under osteogenic differentiation. The dPL was prepared with minimized DNA content and a well-preserved porous structure. Scaffolds were highly porous with interconnected pores and exhibited appropriate swelling and degradation rates supporting saos-2 cell attachment and proliferation. dPL improved scaffold physicochemical features and increased cell proliferation, ALP, OCN, COL I expression, and calcium deposition under osteogenic differentiation induction. nHA.Cs.dPL composite scaffolds provide a 3D microenvironment with superior physicochemical features that support saos-2 cell adhesion, proliferation, and osteogenic differentiation.

9263 Characterization Of A Novel Oral Small Molecule PTH1R Agonist: Proof Of Concept For An Alternative To Injectable Peptide-Based Therapy For Hypoparathyroidism

Abstract Disclosure: J. Zhang: Employee; Self; Septerna Inc.. I. Gomez: None. C. He: Employee; Self; Septerna Inc. J. Wang: Employee; Self; Septerna Inc. X. Du: Employee; Self; Septerna Inc. K. Nguyen: Employee; Self; Septerna Inc. K. Alvarez: Employee; Self; Septerna Inc. A.M. Mirza: Employee; Self; Septerna Inc.. Hypoparathyroidism (HP), a rare endocrine disorder characterized by insufficient levels of parathyroid hormone (PTH), leads to hypocalcemia and hyperphosphatemia. Most HP cases arise due to damage of the parathyroid glands during thyroid or neck surgery. HP symptoms include severe muscle cramps, tingling, burning and numbness, memory loss, and headaches, all leading to a decreased quality of life. Calcium and vitamin D supplementation do not fully ameliorate the disease and may contribute to renal disease. Chronic HP increases the risk of major complications, such as calcium depositions in the brain, eye, and kidneys. Similarly, it can lead to low bone turnover and increased bone mineral density with associated increased bone mineralization. In comparison to standard of care and traditional injectable peptide-based therapies, oral small molecules may have multiple advantages clinically. However, there are no oral small molecules currently in development. PTH functions through activation of the parathyroid hormone 1 receptor (PTH1R), a class B G protein-coupled receptor. The main target tissues for PTH1R activation include bone and kidney. In the kidney, PTH increases tubular reabsorption of calcium and promotes renal excretion of phosphate. In bone, PTH stimulates bone turnover and mobilizes calcium into the circulation to maintain serum calcium. Here we describe the characterization of SP-1462, a novel, potent, and selective oral small molecule, and show that, like the PTH peptides, it acts on PTH1R as an agonist and elicits similar downstream functions in vitro and in vivo. To assess PTH1R engagement in the major targeted organs, kidney and bone, primary human renal proximal epithelial cells (RPTEC) and a human osteoblast cell line (Saos-2) were used, respectively. RPTECs treated with PTH and SP-1462 showed significant changes in transporter genes (SLC22A2 and SLC13A1), immune related genes (CCL2 & DPP4), and matrix reorganization genes (ITGA5 and COL1A1). Saos-2 cells treated with PTH and SP-1462 both significantly affected the expression of Wnt signaling genes (DKK1 and TCF7) and the expression of coupling genes that bridge anabolic/catabolic activities (M-CSF, RANKL, HDAC4, and OPG). Importantly, oral administration of a single dose of SP-1805 in a rat surgical thyroparathyroidectomy (TPTx) model resulted in significant upregulation of serum calcium levels for a period of 24 hours in a dose dependent manner at 3, 10 and 30 mg/kg. The window of calcium upregulation is comparable to injectable PTH peptides currently in development to treat hypoparathyroidism. These data suggest that oral small molecule PTH1R agonists engage PTH pathways similar to native PTH and have the potential to replace injectable PTH peptides to treat PTH-related disorders, including hypoparathyroidism. Presentation: 6/3/2024

6821 Characterization Of A Novel Oral Small Molecule PTH1R Agonist: Proof Of Concept For An Alternative To Injectable Peptide-Based Therapy For Hypoparathyroidism

Abstract Disclosure: J. Zhang: None. I. Gomez: None. C. He: None. J. Wang: None. X. Du: None. K. Nguyen: None. K. Alvarez: None. A.M. Mirza: None. Hypoparathyroidism (HP), a rare endocrine disorder characterized by insufficient levels of parathyroid hormone (PTH), leads to hypocalcemia and hyperphosphatemia. Most HP cases arise due to damage of the parathyroid glands during thyroid or neck surgery. HP symptoms include severe muscle cramps, tingling, burning and numbness, memory loss, and headaches, all leading to a decreased quality of life. Calcium and vitamin D supplementation do not fully ameliorate the disease and may contribute to renal disease. Chronic HP increases the risk of major complications, such as calcium depositions in the brain, eye, and kidneys. Similarly, it can lead to low bone turnover and increased bone mineral density with associated increased bone mineralization. In comparison to standard of care and traditional injectable peptide-based therapies, oral small molecules may have multiple advantages clinically. However, there are no oral small molecules currently in development. PTH functions through activation of the parathyroid hormone 1 receptor (PTH1R), a class B G protein-coupled receptor. The main target tissues for PTH1R activation include bone and kidney. In the kidney, PTH increases tubular reabsorption of calcium and promotes renal excretion of phosphate. In bone, PTH stimulates bone turnover and mobilizes calcium into the circulation to maintain serum calcium. Here we describe the characterization of SP-1462, a novel, potent, and selective oral small molecule, and show that, like the PTH peptides, it acts on PTH1R as an agonist and elicits similar downstream functions in vitro and in vivo. To assess PTH1R engagement in the major targeted organs, kidney and bone, primary human renal proximal epithelial cells (RPTEC) and a human osteoblast cell line (Saos-2) were used, respectively. RPTECs treated with PTH and SP-1462 showed significant changes in transporter genes (SLC22A2 and SLC13A1), immune related genes (CCL2 & DPP4), and matrix reorganization genes (ITGA5 and COL1A1). Saos-2 cells treated with PTH and SP-1462 both significantly affected the expression of Wnt signaling genes (DKK1 and TCF7) and the expression of coupling genes that bridge anabolic/catabolic activities (M-CSF, RANKL, HDAC4, and OPG). Importantly, oral administration of a single dose of SP-1805 in a rat surgical thyroparathyroidectomy (TPTx) model resulted in significant upregulation of serum calcium levels for a period of 24 hours in a dose dependent manner at 3, 10 and 30 mg/kg. The window of calcium upregulation is comparable to injectable PTH peptides currently in development to treat hypoparathyroidism. These data suggest that oral small molecule PTH1R agonists engage PTH pathways similar to native PTH and have the potential to replace injectable PTH peptides to treat PTH-related disorders, including hypoparathyroidism. Presentation: 6/3/2024

Adsorption and Release Pattern of Recombinant Human Bone Morphogenic Proatin 2 onto Different Bone Grafts and its Consequent Osteoblasts` Activation and Neutrophils` Priming

ObjectivesControlled long-term delivery of recombinant human bone morphogenic proatin 2 (rhBMP2) eluted in a collagen scaffolds suffer from only a high initial burst release. The purpose of the current study was to investigate the long-term delivery of rhBMP2 when mixed with different bone grafts and its impact on osteoblastic activity and neutrophil priming. MethodsrhBMP2 was separately mixed with xenograft, allograft, or alloplast and incubated for 30 days. Levels of BMP2 adsorption and their release were measured using immunofluorescence and ELISA respectively. The supernatants from the grafts were then incubated with either osteoblast (Saos-2 cells) or neutrophils (differentiated from HL60) for alkaline phosphatase and oxidative stress measurements respectively. Gene expression of osteoblast functionality and neutrophil priming were measured with qRT-PCR. ResultsrhBMP2 was adsorbed onto all tested grafts, with a superior effect of alloplast. The release of the rhBMP2 from all grafts was similar and sustained for 30 days with the lowest levels in the alloplast group. Activation of osteoblast was robust in the allograft and xenograft groups, concomitant with elevated osteocalcin expression. Neutrophil priming was greatest in the xenograft group, together with elevated expression of interleukin 1β. ConclusionrhBMP2 with bone graft material constitutes its sustained release over time. This, in turn, robust osteoblast and neutrophil activity.

Multifunctional gallium doped bioactive glasses: a targeted delivery for antineoplastic agents and tissue repair against osteosarcoma

Osteosarcoma (OS) is the mostly commonly occurring primary bone cancer. Despite comprehensive treatment programs including neoadjuvant chemotherapy and tumour resection, survival rates have not improved significantly since the 1970s. Survival rates are dramatically reduced for patients who suffer a local recurrence. Furthermore, primary bone cancer patients are at increased risk of bone fractures. Consequently, there is an urgent need for alternative treatment options. In this paper we report the development of novel gallium doped bioactive glass that selectively kill bone cancer cells whilst simultaneously stimulating new bone growth. Here we show, using a combination of 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide, LIVE/DEAD assays and image analysis, that bioactive glasses containing gallium oxide are highly toxic and reduce both the proliferation and migration of bone cancer cells (Saos-2) in a dose dependant manner. Glasses containing 5 mol% gallium oxide reduced the viability of OS cells by 99% without being cytotoxic to the non-cancerous normal human osteoblasts (NHOst) control cells. Furthermore, Fourier transform infrared and energy-dispersive x-ray spectroscopy results confirmed the formation of an amorphous calcium phosphate/hydroxyapatite like layer on the surface of the bioactive glass particulates, after 7 d incubating in simulated body fluid, indicating the early stages of bone formation. These materials show significant potential for use in bone cancer applications as part of a multimodal treatment.

FGF23 and Cell Stress in SaOS-2 Cells-A Model Reflecting X-Linked Hypophosphatemia Dynamics.

Our study investigates the impact of FGF23 overexpression on SaOS-2 cells to elucidate its role in cellular stress and morphology, contributing to the understanding of skeletal pathologies like X-linked hypophosphatemia (XLH). Using transmission electron microscopy and protein analysis (Western blot), we analyzed the rough endoplasmic reticulum (rER) and mitochondria in SaOS-2 cells with FGF23 overexpression compared to controls. We found significant morphological changes, including enlarged and elongated rER and mitochondria, with increased contact zones, suggesting enhanced interaction and adaptation to elevated protein synthesis and secretion demands. Additionally, we observed higher apoptosis rates of the cells after 24-72 h in vitro and upregulated proteins associated with ER stress and apoptosis, such as CHOP, XBP1 (spliced and unspliced), GRP94, eIF2α, and BAX. These findings indicate a robust activation of the unfolded protein response (UPR) and apoptotic pathways due to FGF23 overexpression. Our results highlight the critical role of ER and mitochondrial interactions in cellular stress responses and provide new insights into the mechanistic link between FGF23 signaling and cellular homeostasis. In conclusion, our study underscores the importance of analyzing UPR-related pathways in the development of therapeutic strategies for skeletal and systemic diseases and contributes to a broader understanding of diseases like XLH.

Sol-Gel SiO2 Coatings with Curcumin and Thymol on 3D Printouts Manufactured from Ti6Al4V ELI

Bacterial biofilm on implants may cause inflammation, which disturbs the process of the implant’s integration with the surrounding tissues. Such problems are becoming critical for patients’ health, especially in connection with the presence of antibiotic-resistant bacterial strains. Among the existing alternatives for drug treatments are natural-based substances. This study focused on the examination of silica coatings with curcumin and thymol, which were deposited using the sol-gel method on 3D printouts made of Ti6Al4V ELI. This substrate material is commonly used in medicine. The selective laser melting technique used for the manufacturing of samples was in line with the existing procedures applied for individual orthopedic implants. The examination involved the assessment of the coatings’ morphology, chemical composition, and biological effect. The antibacterial properties were tested using a flow cytometer using Escherichia coli, and the cytotoxicity on Saos-2 cells was assessed using the LIVE/DEAD test. The obtained results showed that it is possible to produce silica sol-gel coatings with the addition of specific natural substances in concentrations assuring a bacteriostatic effect. The produced coatings did not show any cytotoxic effect, which confirms the possibility of using both curcumin and thymol as additives to coatings used in medicine, e.g., for orthopedic implants.

Unlocking the Secrets of Adipose Tissue: How an Obesity-Associated Secretome Promotes Osteoblast Dedifferentiation via TGF-β1 Signaling, Paving the Path to an Adipogenic Phenotype.

Obesity poses a significant global health challenge, given its association with the excessive accumulation of adipose tissue (AT) and various systemic disruptions. Within the adipose microenvironment, expansion and enrichment with immune cells trigger the release of inflammatory mediators and growth factors, which can disrupt tissues, including bones. While obesity's contribution to bone loss is well established, the direct impact of obese AT on osteoblast maturation remains uncertain. This study aimed to explore the influence of the secretomes from obese and lean AT on osteoblast differentiation and activity. SAOS-2 cells were exposed to the secretomes obtained by culturing human subcutaneous AT from individuals with obesity (OATS) or lean patients, and their effects on osteoblasts were evaluated. In the presence of the OATS, mature osteoblasts underwent dedifferentiation, showing an increased proliferation accompanied by a morphological shift towards a mesenchymal phenotype, with detrimental effects on osteogenic markers and the calcification capacity. Concurrently, the OATS promoted the expression of mesenchymal and adipogenic markers, inducing the formation of cytoplasmic lipid droplets in SAOS-2 cells exposed to an adipogenic differentiation medium. Additionally, TGF-β1 emerged as a key mediator of these effects, as the OATS was enriched with this growth factor. Our findings demonstrate that obese subcutaneous AT promotes the dedifferentiation of osteoblasts and increases the adipogenic profile in these cells.

Ezetimibe Inhibits Cell Viability and Invasion by Suppressing PI3K/AKT Signaling Pathway in Human Osteosarcoma Cells

Introduction: Osteosarcoma is one of the most prevalent malignant bone tumors with a poor overall prognosis and mainly happens in children and adolescents. Current therapy strategies still possess a lot of limitations, and new and efficient strategies are required. Ezetimibe was previously reported to have its anti-tumor effect in various tumors, but the investigation of Ezetimibe on osteosarcoma is still limited. Aims: This study explores whether ezetimibe could exert an anti-tumor effect on human osteosarcoma cell lines, U2OS, and Saos-2. Methods: The effect of ezetimibe on the proliferation of osteosarcoma was explored by CCK-8 and colony formation assay. The role of ezetimibe on osteosarcoma cell migration and invasion was explored by wound healing assay and transwell assay. The role of ezetimibe on osteosarcoma cell apoptosis was explored by PI/Annexin V analysis. In addition, a western blot was performed to verify the phenotype. Results: The flow cytometry assay indicated that ezetimibe could promote osteosarcoma apoptosis. Western blot assay further demonstrated the effect of ezetimibe on proliferation, migration, invasion and apoptosis- related proteins. Finally, the deep anti-tumor effect of ezetimibe contributed to suppressing the PI3K/AKT signaling pathway. Conclusion: Present data indicated that ezetimibe has an antitumor effect on osteosarcoma and could be considered a future osteosarcoma treatment.

Bromelain-facilitated GNPs: A strategic innate anticancer delivery system for methotrexate into osteosarcoma cells

Osteosarcoma is the most common malignant bone tumor in children and adolescents during rapid bone growth. Traditional chemotherapy has markedly improved patient outcomes but suffers from nonspecific side effects due to nonspecific drug distribution, highlighting the need for targeted therapies. Methotrexate, although effective, poses toxicity concerns and prompts exploration into advanced drug delivery systems like nanoparticles. Here, we developed a novel method of synthesizing gold nanoparticles using bromelain (G-BNPs) as a reducing and capping agent, and we conjugated G-BNPs with methotrexate (G-B-MNPs) via 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (EDC/NHS) as crosslinker. Our meticulous characterization, which included UV–visible spectroscopy, Transmission electron microscopy (TEM), Dynamic light scattering (DLS), Zeta potential, and Fourier-transform infrared spectroscopy (FTIR) analyses confirmed the successful fabrication and drug conjugation of the G-BNPs. We then evaluated the cytotoxicity of the G-BNPs (sized ∼ 21 nm) and G-B-MNPs (sized ∼ 24 nm) on the osteosarcoma cell lines, Saos-2 and MG-63, as well as the non-cancerous primary osteoblast cells. Our findings revealed that G-B-MNPs significantly increased the cytotoxic impact on osteosarcoma cells compared to methotrexate alone while showing minimal toxicity toward primary osteoblast cells. Importantly, using 4`,6-diamidino-2-phenylindole(DAPI), we demonstrated that G-B-MNPs were delivered directly into the nucleus of the cells without encountering lysosomes. G-B-MNPs can be considered a potential drug delivery method for osteosarcoma treatment by improving effectiveness and reducing adverse effects, thereby enhancing patient prognosis.

The effect of surface roughness and wettability on the adhesion and proliferation of Saos-2 cells seeded on 3D printed poly(3-hydroxybutyrate)/polylactide (PHB/PLA) surfaces

The aim of this work is to explore the effect of surface characteristics of the 3D printed scaffolds on their suitability for Saos-2 cells growth. Two promising materials for bone tissue engineering were examined, both containing poly(3-hydroxybutyrate)/poly(d,l-lactide) plasticized blend and one of them filled with bioactive tricalcium phosphate. The surface free energy (SFE) of samples was determined by contact angle measurement with four liquids. For non-filled sample the water contact angle (WCA) was 74° and its SFE was 40 mN m−1. The composite sample exhibited substantially decreased WCA, 61°. Moreover, the addition of the tricalcium phosphate caused doubling of the polar component of the SFE which increased by a total of 13%. 3D printed surfaces prepared by fused deposition modeling method showed a profound increase of WCA due to the increase in their surface roughness which was analyzed by confocal microscopy. The change in wetting properties strongly affected the behavior of Saos-2 cells on printed surfaces. The number of cells as measured by DNA quantification linearly decreased with increasing surface WCA. The highest number of cells was observed on the pressed samples and 3D printed surfaces made of simple lines and a grid with 50 μm gap between lines. The favored surfaces exhibit WCA under 80° which is important information for the future design of the scaffolds.

Effects of photobiomodulation on different phases of in vitro osteogenesis.

The present study aimed to evaluate the effect of photobiomodulation therapy (PBM) on different stages of osteogenesis in vitro. For this, osteoblastic-like cells (Saos-2 cell lineage) were irradiated in two different periods: during the Proliferation phase (PP; from the second to the fourth day) and during the Differentiation phase (DP; from the seventh to the ninth day). The energy density used in the study was 1.5J/ cm2. The following parameters were evaluated: 1) quantification ofcollagen type 1 (COL 1), osteopontin (OPN), and bone morphogenetic protein 2 (BMP-2); 2) quantification of alkaline phosphatase (ALP) activity; and 3) quantification of extracellular matrix (ECM)mineralization. Non-irradiated cultures were used as controls. The data were analyzed using the Student's t-test or one-way ANOVA, considering a significance level of 5%. The results indicated that COL 1 and BMP-2 quantification was higher in Saos-2 irradiated during the DP in relation to the control group at day 10 (p < 0.05). No differences were observed for other comparisons at this time point(p>0.05).OPN expression was greater in PP compared with the other experimental groups at day 10 (p < 0.05). Irradiation did not affect ALP activity in Saos-2 regardless of the exposure phase and the time point evaluated (p > 0.05). At day 14, ECMmineralization was higher in Saos-2 cultures irradiated during the DP in relation to the PP (p < 0.05). In conclusion, the results suggested that the effects of PBM on osteoblastic cells may be influenced by the stage of cell differentiation.

Direct ink writing of biomimetic hydroxyapatite scaffolds with tailored concave porosity

Direct ink writing is a promising technology for the fabrication of personalized bone grafts, as it enables the customization of their geometrical conformation with high reproducibility and is compatible with the use of self-setting calcium deficient hydroxyapatite inks. However, the scaffolds obtained by DIW consist mostly of convex filaments, which is a limitation since concave surfaces have been shown to promote bone regeneration in vivo. In this work, we explore the use of triply periodic minimal surface (TPMS) designs in DIW of calcium phosphate self-hardening inks as a strategy to obtain scaffolds with controlled concave macropores. The limitations of the printing parameters with high ceramic loaded inks used in DIW enabled achieving only 20% nominal porosities of Gyroid-, Diamond- and Schwarz-based structures. The inherent layered pores from TPMS geometries allowed obtaining concavities typically unattainable via DIW, bearing substantial implications for subsequent osteoinductive capabilities. Although the mechanical properties were lower in the TPMS-based scaffolds than in the orthogonal patterned ones, the blood permeability of the TPMS-based structures was higher. The concave pore architecture enhanced the osteogenic potential of the biomimetic ceramic, increasing SaOs-2 cell adhesion, proliferation, differentiation and mineralisation.&amp;nbsp;&amp;nbsp;

Characterization of Iron Oxide Nanotubes Obtained by Anodic Oxidation for Biomedical Applications-In Vitro Studies.

To improve the biocompatibility and bioactivity of biodegradable iron-based materials, nanostructured surfaces formed by metal oxides offer a promising strategy for surface functionalization. To explore this potential, iron oxide nanotubes were synthesized on pure iron (Fe) using an anodic oxidation process (50 V-30 min, using an ethylene glycol solution containing 0.3% NH4F and 3% H2O, at a speed of 100 rpm). A nanotube layer composed mainly of α-Fe2O3 with diameters between 60 and 70 nm was obtained. The effect of the Fe-oxide nanotube layer on cell viability and morphology was evaluated by in vitro studies using a human osteosarcoma cell line (SaOs-2 cells). The results showed that the presence of this layer did not harm the viability or morphology of the cells. Furthermore, cells cultured on anodized surfaces showed higher metabolic activity than those on non-anodized surfaces. This research suggests that growing a layer of Fe oxide nanotubes on pure Fe is a promising method for functionalizing and improving the cytocompatibility of iron substrates. This opens up new opportunities for biomedical applications, including the development of cardiovascular stents or osteosynthesis implants.

Sirtuin 3-activated superoxide dismutase 2 mediates fluoride-induced osteoblastic differentiation in vitro and in vivo by down-regulating reactive oxygen species.

Skeletal fluorosis is a chronic metabolic bone disease caused by long-term excessive fluoride intake. Abnormal differentiation of osteoblasts plays an important role in disease progression. Research on the mechanism of fluoride-mediated bone differentiation is necessary for the prevention and treatment of skeletal fluorosis. In the present study, a rat model of fluorosis was established by exposing it to drinking water containing 50mg/L F-. We found that fluoride promoted Runt-related transcription factor 2 (RUNX2) as well as superoxide dismutase 2 (SOD2) and sirtuin 3 (SIRT3) expression in osteoblasts of rat bone tissue. In vitro, we also found that 4mg/L sodium fluoride promoted osteogenesis-related indicators as well as SOD2 and SIRT3 expression in MG-63 and Saos-2 cells. In addition, we unexpectedly discovered that fluoride suppressed the levels of reactive oxygen species (ROS) and mitochondrial reactive oxygen species (mtROS) in osteoblasts. When SOD2 or SIRT3 was inhibited in MG-63 cells, fluoride-decreased ROS and mtROS were alleviated, which in turn inhibited fluoride-promoted osteogenic differentiation. In conclusion, our results suggest that SIRT3/SOD2 mediates fluoride-promoted osteoblastic differentiation by down-regulating reactive oxygen species.

Apoptotic Induction by Biosynthesized Gold Nanoparticles Using Phormidesmis communis Strain AB_11_10 against Osteosarcoma Cancer.

Phormidesmis communis strain AB_11_10 was isolated and identified using microscopy and 16s rRNA sequencing, and its phytochemical constituents were determined using liquid chromatography-quadrupole time-of-flight mass spectrometry. The isolate had a segmented filamentous shape with a blue-green color. Many biomolecules, including organic compounds, amino acids, and fatty acids, were detected. P. communis strain AB_11_10 was used to synthesize gold nanoparticles (Ph-AuNPs) by adjusting the optimum reaction conditions. The concentration, algal/precursor ratio, temperature, reaction time, and pH significantly influenced the synthesis of the Ph-AuNPs. Mixing 1 mL of 0.5 mM of HAuCl4 with 1 mL of algal extract and exposing the mixture to 100 °C for 30 min at pH 5.6 were the optimum conditions for the biosynthesis of Ph-AuNPs at a wavelength of 524.5 nm. The Ph-AuNPs were characterized using TEM, SEM, EDX, and mapping Zeta sizer and FTIR. The Ph-AuNPs had quasi-spherical to triangular shapes with an average diameter of 9.6 ± 4.3 nm. Ph-AuNPs composed of 76.10 ± 3.14% of Au and trace amounts of carbon and oxygen were detected, indicating that the P. communis strain AB_11_10 successfully synthesized Ph-AuNPs. The hydrodynamic diameter of the Ph-AuNPs was 28.5 nm, and their potential charge was -17.7 mV. O-H, N-H, C=C, N-O, C-H, and C-O were coated onto the surfaces of the Ph-AuNPs. These groups correspond to algal phytochemicals, which may have been the main reducing and stabilizing substances during the Ph-AuNP synthesis. The therapeutic activity of the Ph-AuNPs against osteosarcoma cancers was examined in MG-63 and SAOS-2 cell lines, while their biocompatibility was tested against Vero cell lines using a sulforhodamine B assay. The Ph-AuNPs had potent antitumor activity against the MG-63 and SAOS-2 cells, with a low toxicity toward Vero cells. Flow cytometry and cell cycle arrest analyses revealed that the Ph-AuNPs enhanced the apoptotic pathway and arrested the cell cycle in the MG-63 and SAOS-2 cells. P. communis strain AB_11_10 provides a new source to synthesize small, stable, and biocompatible AuNPs that act as apoptotic enhancers in osteosarcoma.

DEPDC1 affects autophagy-dependent glycolysis levels in human osteosarcoma cells by modulating RAS/ERK signaling through TTK.

The current treatment for osteosarcoma (OS) is based on surgery combined with systemic chemotherapy, however, gene therapy has been hypothesized to improve patient survival rates. The density-enhanced protein domain 1 protein (DEPDC1) functions as a crucial determinant in the advancement of OS, which is highly expressed in OS cells. The current study was designed to delve into the effect and mechanism of DEPDC1 and phosphotyrosine-picked threonine tyrosine kinase (TTK) in OS. The expression of DEPDC1 and TTK in OS cells was detected by western blotting. Furthermore, the assessment of glycolysis encompassed the quantification of extracellular acidification rate, glucose uptake rate, lactate concentration, and the expression of glucose transporter 1, hexokinase 2, and pyruvate kinase M2. Finally, the functions of DEPDC1 and TTK in autophagy and ras-extracellular signal-regulated kinase signaling were determined by western blotting after interfering with DEPDC1 in SaOS-2 cells. The results revealed that DEPDC1 and TTK were upregulated in OS cell lines and interfering with DEPDC1 inhibited glycolysis and autophagy in OS cells. Furthermore, the STRING database suggested that DEPDC1 and TTK perform targeted binding. Notably, the results of the present study revealed that DEPDC1 upregulated RAS expression through TTK and enhanced ERK activity, thereby affecting glycolysis and autophagy in OS cells. Collectively, the present investigation demonstrated that DEPDC1 affected autophagy-dependent glycolysis levels of OS cells by regulating RAS/ERK signaling through TTK.