Proliferation Of Saos-2 Cells Research Articles

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.  

Innovative hydroxyapatite/submicron mesoporous SiO2/HA particles composite coatings for enhanced osteogenic activity of NiTi bone implants: A comprehensive investigation of materials and biological interactions

In this study, hydroxyapatite (HA) incorporated in mesoporous SiO2 particles (SiO2/HA) was initially synthesized using a soft template method. The resulting structure owned a high surface area (796.62 m2 g-1) and a substantial pore volume (0.757 cm3 g-1). The TEM and FESEM images indicated that the synthesized mesoporous particles possessed a spherical morphology, with a diameter of approximately 200 nm, and pores of slit-shape. The mission was to improve the surface characteristics of NiTi implants by composite coatings. This investigation emphasized specifically the impact of different concentrations of mesoporous SiO2/HA particles within the electrolyte on the properties of HA/mesoporous composite coatings. The surface characteristics of the coatings were examined using ATR-FTIR, FESEM, EDS, AFM, and hydrophilicity measurements. Furthermore, the osteogenic activity of the coatings was evaluated by culturing the osteosarcoma cell line SAOS-2 on the coated samples. The introduction of mesoporous particles resulted in a decrease in the coatings’ surface roughness along with an improvement in their wettability. Moreover, there was an enhancement in the cell viability (99% after 7 days), proliferation, adhesion, and growth of SAOS-2 cells at the optimized concentration of mesoporous SiO2/HA particles (1000 mg/L). DAPI images illustrated that the mesoporous particles did not cause any adverse impact on the cellular nuclei. Finally, in the apoptosis test, the composite coating displayed a reduced number of necrotic cells compared to the pure HA coating.

A theragenerative bio-nanocomposite consisting of black phosphorus quantum dots for bone cancer therapy and regeneration

Recently, the term theragenerative has been proposed for biomaterials capable of inducing therapeutic approaches followed by repairing/regenerating the tissue/organ. This study is focused on the design of a new theragenerative nanocomposite composed of an amphiphilic non-ionic surfactant (Pluronic F127), bioactive glass (BG), and black phosphorus (BP). The nanocomposite was prepared through a two-step synthetic strategy, including a microwave treatment that turned BP nanosheets (BPNS) into quantum dots (BPQDs) with 5 ± 2 nm dimensions in situ. The effects of surfactant and microwave treatment were assessed in vitro: the surfactant distributes the ions homogenously throughout the composite and the microwave treatment chemically stabilizes the composite. The presence of BP enhanced bioactivity and promoted calcium phosphate formation in simulated body fluid. The inherent anticancer activity of BP-containing nanocomposites was tested against osteosarcoma cells in vitro, finding that 150 μg mL−1 was the lowest concentration which prevented the proliferation of SAOS-2 cells, while the counterpart without BP did not affect the cell growth rate. Moreover, the apoptosis pathways were evaluated and a mechanism of action was proposed. NIR irradiation was applied to induce further proliferation suppression on SAOS-2 cells through hyperthermia. The inhibitory effects of bare BP nanomaterials and nanocomposites on the migration and invasion of bone cancer, breast cancer, and prostate cancer cells were assessed in vitro to determine the anticancer potential of nanomaterials against primary and secondary bone cancers. The regenerative behavior of the nanocomposites was tested with healthy osteoblasts and human mesenchymal stem cells; the BPQDs-incorporated nanocomposite significantly promoted the proliferation of osteoblast cells and induced the osteogenic differentiation of stem cells. This study introduces a new multifunctional theragenerative platform with promising potential for simultaneous bone cancer therapy and regeneration.

Effects of Daidzein, Tempeh, and a Probiotic Digested in an Artificial Gastrointestinal Tract on Calcium Deposition in Human Osteoblast-like Saos-2 Cells.

Adequate calcium intake is crucial for the prevention and treatment of bone-related issues. Developing a nutritional source of readily bioavailable calcium is particularly significant for individuals deficient in this essential element and at risk of developing osteoporosis. This research aimed to evaluate the impact of tempeh (T), daidzein (D), and Lactobacillus acidophilus (LA) within a simulated intestinal environment consisting of Caco-2 epithelial and Saos-2 cells, focusing on their implications for bone mineralization mechanisms. In the initial phase, calcium bioaccessibility from calcium citrate (CaCt), LA, D, the daidzein combination D-CaCt-LA (D1:1:1), and the tempeh combination T-CaCt-LA (T1:1:1) was assessed through digestion simulation. The calcium content of both untreated and digested samples was determined using atomic absorption spectrometry (AAS). In the subsequent stage, the digested samples were used to induce intestinal absorption in differentiated enterocyte-like Caco-2 cells. The permeable fractions were then evaluated in a culture of osteoblast-like Saos-2 cells. Preliminary cellular experiments employed the MTT assay to assess cytotoxicity. The results indicated that the analyzed products did not influence the deposition of extracellular calcium in Saos-2 cells cultured without mineralization stimulators. The combined formulations of permeable fractions of digested CaCt, LA, D, and T demonstrated the capacity to enhance the proliferation of Saos-2 cells. In Saos-2 cells, D, D1:1:1, and LA showed no discernible impact on intracellular calcium accumulation, whereas T and T1:1:1 reduced the calcium deposits. Additionally, mRNA transcripts and alkaline phosphatase (ALP) activity levels in Saos-2 cells cultured without mineralization induction were unaffected by the analyzed products. An examination of the products revealed no discernible effect on ALP activity or mRNA expression during Saos-2 cell differentiation. Our findings suggest that tempeh, daidzein, and L. acidophilus did not positively impact cellular calcium deposition in Saos-2 cells. However, tempeh, daidzein and its combination, and L. acidophilus might enhance the process of osteogenic differentiation in Saos-2 cells. Nevertheless, this study did not identify any synergistic impact on calcium deposition and the process of osteogenic differentiation in Saos-2 cells of isoflavones and probiotics.

NOVEL CB65-LOADED LIPOSOME FORMULATION AS A CHEMOTHERAPEUTIC CANDIDATE FOR OSTEOSARCOMA

Osteosarcoma is common in children and adolescents with high mortality due to rapid progression. Therapeutic approaches for osteosarcoma are limited and may cause side effects. Cannabinoid ligands exert antiproliferative, apoptotic effect in cancer cells via CB1/2 or TRPV1 receptors. In this study, we hypothesized that synthetic specific CB2R agonist CB65 might have an antiproliferative and apoptotic effect on osteosarcoma cell lines in vitro. If so, this agent might be a chemotherapeutic candidate for osteosarcoma, with prolonged release, increased stability and bioavailability when loaded into a liposomal system. We first determined CB2 receptor expression in MG63 and Saos-2 osteosarcoma cells by qRT- PCR and FCM. CB65 reduced proliferation in osteosarcoma cells by WST-1 and RTCA. IC50 for MG63 and Saos-2 cells were calculated as 1.11×10-11 and 4.95×10-11 M, respectively. The antiproliferative effect of CB65 on osteosarcoma cells was inhibited by CB2 antagonist AM630. IC50 of CB65 induced late apoptosis of MG63 and Saos-2 cells at 24 and 48 hours, respectively by FCM. CB65 was loaded into the liposomal system by thin film hydration method and particle size, polydispersity index, and zeta potentials were 141.7±0.6 nm, 0.451±0.026, and -10.9±0.3 mV, respectively. The CB65-loaded liposomal formulation reduced MG63 and Saos-2 cell proliferation by RTCA. IC50 of CB65 and CB65-loaded liposomal formulation induced late apoptosis of MG63 and Saos-2 cells at 24 and 48 hours, respectively, by FCM. Scratch width was higher in CB65 and CB65-loaded liposome-treated cells compared to control. In this study, the real-time antiproliferative and apoptotic effect of synthetic specific CB2 agonist CB65 in osteosarcoma cell lines was demonstrated for the first time, and the real time therapeutic window was determined. The CB65-loaded liposomal formulation presents a potential treatment option that can be translated to clinic following its validation within animal models and production under GMP conditions.

Circ_KIAA0922 regulates Saos-2 cell proliferation and osteogenic differentiation by regulating the miR-148a-3p/SMAD5 axis and activating the TGF-β signaling pathway.

Circular RNAs (circRNAs) are emerging as important regulators in human disease, but their function in osteoporosis (OP) is not sufficiently known. The aim of this study was to identify the possible molecular mechanism of circ_KIAA0922 in osteogenic differentiation of Saos-2 cells in vitro and the interactions among circ_KIAA0922, miR-148a-3p, and SMAD family member 5 (SMAD5). Circ_ KIAA0922, miR-148a-3p, and SMAD5 were overexpressed by transient transfection. Dual-luciferase reporter assay system was used to analyze the combination among circ_KIAA0922, miR-148a-3p, and SMAD5. In addition, the levels of circ_KIAA0922, miR-148a-3p, SMAD5, osteocalcin (OCN), and runt-related transcription factor 2 (RUNX2) were detected using RT-qPCR or western blot analysis. Alizarin red staining was performed to analyze the degree of osteogenic differentiation under the control of circ_KIAA0922, miR-148a-3p, and SMAD5. We found that circ_KIAA0922 knockdown inhibited the proliferation and osteogenic differentiation of Saos-2 cells. Circ_KIAA0922 directly targeted miR-148a-3p, and miR-148a-3p inhibition reversed the effects of circ_KIAA0922 knockdown on the proliferation and osteogenic differentiation of Saos-2 cells. Overexpression of SMAD5 promoted the proliferation and osteogenic differentiation of Saos-2 cells and attenuated the inhibitory effect of miR-148a-3p on cell proliferation and osteogenic differentiation. In conclusion, circ_ KIAA0922 facilitated Saos-2 cell proliferation and osteogenic differentiation via the circ_KIAA0922/ miR-148a-3p/ SMAD5 axes in vitro, thus providing insights into the mechanism of osteogenic differentiation by circ_ KIAA0922.

Anticancer Potential of Farnesol Against Human Osteosarcoma Saos-2 Cells and Human Colorectal Carcinoma HCT-116 Cells.

Increased colorectal carcinoma (CRC) and osteosarcomaprevalence, low survival rate, poor prognosis, and the limitations of existing anticancer therapies like side effects of drugs, non-specificity, short half-life, etc., pose a need for novel anticancer drugs.Farnesol, an organic sesquiterpene compound, found in the essential oils of various plants has been shown to possess antioxidant, anti-inflammatory, and anticancer properties. However, the anticancer effect of farnesol againstCRCand osteosarcoma has not yet been adequately elucidated. The aim of the study was to analyze the anticancer effects of farnesol against human osteosarcoma and CRC cell lines. Human osteosarcoma (Saos-2) and colorectal carcinoma (HCT-116) cell lines were procured and cultured at37oC and 5% CO2. The cells were treated with 10, 20, 40, 60, 80, and 100 µM/ml and 20, 40, 60, 80, 100, and 120 µM/ml of farnesol for 24 hours, respectively.3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromideassay was performed to assess the cytotoxicity of farnesol on Saos-2 and HCT-116 cells. Acridine orange/ethidium bromidestaining was carried out to analyze apoptosis.4',6-diamidino-2-phenylindolestaining was done to observe the nuclear changes.Dichloro-dihydro-fluorescein diacetatestaining was performed to assess the farnesol-induced reactive oxygen species (ROS)-mediated cell death. Farnesol reduced the viability and proliferation of Saos-2 and HCT-116 cells in a dose-dependent manner. Farnesol was able to alter the cellular and nuclear morphology of Saos-2 and HCT-116 cells, promoting cell death. Farnesol-induced apoptosis inhuman osteosarcoma and colorectal carcinoma cell lines. Early apoptosis was observed in farnesol-treated HCT-116 cells. Additionally, ROS-mediated apoptotic cell death was reported in Saos-2 cells. Farnesol has the potential to induce cytotoxicity against human osteosarcoma and CRC cell lines.

In vitro and in vivo killing effects of methionine enkephalin on osteosarcoma

ObjectiveThis study aimed to investigate the underlying regulatory effects of methionine enkephalin (MENK) on osteosarcoma. MethodsThe Cell Counting Kit-8 assay, clone formation, wound healing, transwell assay, and flow cytometry were performed to measure the effects of MENK on the proliferation, migration, invasion, and apoptosis of MG-63 and Saos-2 cells. Opiate growth factor receptor expression (OGFr) in cells was stably knocked down using siRNA. A tumor model was established by inoculating MG-63 cells into mice. Flow cytometry was performed to identify alterations in mice bone marrow, spleen, and tumor tissue immune cells. The phenotype of tumor-associated macrophages was determined using immunohistochemistry. After OGFr knockdown or/and treatment with MENK, Bax, Bcl-2, caspase 3, caspase 9, and PARP expression levels were characterized using qRT-PCR, western blot, and WES, respectively. ResultsMENK could significantly inhibit the proliferation, invasion, and migration of MG-63 and Saos-2, arrest the cell cycle in the G0/G1 phase, upregulate Bax, caspase 3, caspase 9, and PARP expression, and downregulate Bcl-2 expression. Tumor size and weight were lower in the MENK group than those in the control group. MENK-treated mice exhibited a reduced ratio of CD11b + Gr-1 + myeloid-derived suppressor cells. MENK increased the ratio of M1-type macrophages and decreased the proportion of M2-type macrophages in tumor tissue. Furthermore, the level of TNF-α significantly increased while that of IL-10 decreased in MENK-treated mice. The effect of MENK could be partly reversed by OGFr knockdown. ConclusionMENK reduces the abundance of myeloid-derived suppressor cells, induces M1 polarization of macrophages, and exhibits an inhibitory effect on osteosarcoma.

Differing responses of osteogenic cell lines to β-glycerophosphate

Ascorbic acid (Asc), dexamethasone (Dex) and β-glycerophosphate (β-Gly) are commonly used to promote osteogenic behaviour by osteoblasts in vitro. According to the literature, several osteosarcoma cells lines appear to respond differently to the latter with regards to proliferation kinetics and osteogenic gene transcription. Unsurprisingly, these differences lead to contrasting data between publications that necessitate preliminary studies to confirm the phenotype of the chosen osteosarcoma cell line in the presence of Asc, Dex and β-Gly. The present study exposed Saos-2 cells to different combinations of Asc, Dex and β-Gly for 14 days and compared the response with immortalised human mesenchymal stromal/stem cells (MSCs). Cell numbers, cytotoxicity, mineralised matrix deposition and cell proliferation were analysed to assess osteoblast-like behaviour in the presence of Asc, Dex and β-Gly. Additionally, gene expression of runt-related transcription factor 2 (RUNX2); osteocalcin (OCN); alkaline phosphatase (ALP); phosphate regulating endopeptidase homolog X-linked (PHEX); marker of proliferation MKI67 and proliferating cell nuclear antigen (PCNA) was performed every two days during the 14-day cultures. It was found that proliferation of Saos-2 cells was significantly decreased by the presence of β-Gly which contrasted with hMSCs where no change was observed. Furthermore, unlike hMSCs, Saos-2 cells demonstrated an upregulated expression of late osteoblastic markers, OCN and PHEX that suggested β-Gly could affect later stages of osteogenic differentiation. In summary, it is important to consider that β-Gly significantly affects key cell processes of Saos-2 when using it as an osteoblast-like cell model.

Tuning of Silver Content on the Antibacterial and Biological Properties of Poly(ɛ-caprolactone)/Biphasic Calcium Phosphate 3D-Scaffolds for Bone Tissue Engineering.

There is a growing interest in tissue engineering, in which biomaterials play a pivotal role in promoting bone regeneration. Furthermore, smart functionalization can provide biomaterials with the additional role of preventing orthopedic infections. Due to the growing microbial resistance to antimicrobials used to treat those infections, metal ions, such as silver, thanks to their known wide range of bactericidal properties, are believed to be promising additives in developing antibacterial biomaterials. In this work, novel poly(ε-caprolactone) (PCL)-based 3D scaffolds have been designed and developed, where the polymer matrix was modified with both silver (Ag), to supply antibacterial behavior, and calcium phosphates (biphasic calcium phosphate, BCP) particles to impart bioactive/bioresorbable properties. The microstructural analysis showed that constructs were characterized by square-shaped macropores, in line with the morphology and size of the templating salts used as pore formers. Degradation tests demonstrated the important role of calcium phosphates in improving PCL hydrophilicity, leading to a higher degradation degree for BCP/PCL composites compared to the neat polymer after 18 days of soaking. The appearance of an inhibition halo around the silver-functionalized PCL scaffolds for assayed microorganisms and a significant (p < 0.05) decrease in both adherent and planktonic bacteria demonstrate the Ag+ release from the 3D constructs. Furthermore, the PCL scaffolds enriched with the lowest silver percentages did not hamper the viability and proliferation of Saos-2 cells. A synergic combination of antimicrobial, osteoproliferative and biodegradable features provided to 3D scaffolds the required potential for bone tissue engineering, beside anti-microbial properties for reduction in prosthetic joints infections.

Exploring the molecular mechanism of linagliptin in osteosarcoma cell lines for anti-cancer activity

BackgroundFinding new applications for widely used current drugs is a fast and effective technique for discovering new anticancer chemicals. Osteosarcoma (OS), the most prevalent form of bone cancer, has several side effects that significantly lower patients’ quality of life. This study aims to systematically examine the anti-cancer activity of linagliptin (LG) in the osteosarcoma cell line Saos-2. MethodsMTT assays and flow cytometry were used to assess cell viability and apoptosis, respectively. qPCR array experiments were carried out to determine target gene expressions and explain the molecular mechanism of LG’s action. ResultsLinagliptin treatment significantly decreased the viability of Saos-2 cells and hFOB1.19 cells (p < 0.001). The treatment also induced increased apoptotic effects in both Saos-2 cells (p < 0.001) and hFOB1.19 cells (p < 0.05). qPCR assays were conducted to assess cancer pathway analysis after applying specific quantities of LG to Saos-2 and hFOB1.19 cells. ConclusionThe findings of this study demonstrate that LG inhibits the proliferation of Saos-2 cells and induces cell death. LG supports cell death by suppressing the expression of specific genes involved in cancer pathways.

Comparative Study of Ozonated Glycerol and Macrogol Ointment on Bone Matrix Production by Human Osteosarcoma Cell Line Saos-2.

Ozonated glycerol is glycerol containing ozone, has no unpleasant odor, and has a long half-life. To apply ozonated glycerol for clinical use, ozonated macrogol ointment has been developed by adding macrogol ointment to ozonated glycerol to increase the retention in the affected area. However, the effects of ozone on this macrogol ointment were unclear. The viscosity of the ozonated macrogol ointment was approximately two times higher than that of ozonated glycerol. The effect of the ozonated macrogol ointment on the human osteosarcoma cell line Saos-2 (Saos-2 cells) proliferation, type 1 collagen production, and alkaline phosphatase (ALP) activity were studied. The proliferation of Saos-2 cells was assessed using MTT and DNA synthesis assays. Type 1 collagen production and ALP activity were studied using ELISA and ALP assays. Cells were treated for 24 h with or without 0.05, 0.5, or 5 ppm ozonated macrogol ointment. The 0.5 ppm ozonated macrogol ointment significantly elevated Saos-2 cell proliferation, type 1 collagen production, and ALP activity. These results also showed almost the same trend as for ozonated glycerol.

A Silver Compound with Potential Applications as an Anticancer, Antibacterial, Antifungal, and Anti-Alzheimer's Agent.

This study investigated the biological activity of the silver coordination compound K-22. The IC50 values of K-22 on cancer cell lines range from 0.797 μg/mL to 3.426 μg/mL, indicating that K-22 might preferably inhibit A549, Saos-2, MCF-7, and HT-29 cell proliferation and thus have better therapeutic activity. Furthermore, K-22 stimulated apoptosis via up-regulation of the mRNA and protein expression level of Bax/Bcl-2 ratio in A549, Saos-2, MCF-7, and HT-29. K-22 exhibited antimicrobial activity against S. aureus, E. faecalis, K. pneumonia, P. aeruginosa, C. utilis, and C. albicans. Experimental results show that the compound has inhibitory potential with an IC50 value of 178.10 μM for the BChE (butyrylcholinesterase) enzyme, which has a vital role in the progression of Alzheimer's disease. As a result, compound K-22 exhibits a strong potential for medical use due to its anticancer, antibacterial, antifungal, and anti-Alzheimer properties.

Dual-Action Effect of Gallium and Silver Providing Osseointegration and Antibacterial Properties to Calcium Titanate Coatings on Porous Titanium Implants.

Previously, functional coatings on 3D-printed titanium implants were developed to improve their biointegration by separately incorporating Ga and Ag on the biomaterial surface. Now, a thermochemical treatment modification is proposed to study the effect of their simultaneous incorporation. Different concentrations of AgNO3 and Ga(NO3)3 are evaluated, and the obtained surfaces are completely characterized. Ion release, cytotoxicity, and bioactivity studies complement the characterization. The provided antibacterial effect of the surfaces is analyzed, and cell response is assessed by the study of SaOS-2 cell adhesion, proliferation, and differentiation. The Ti surface doping is confirmed by the formation of Ga-containing Ca titanates and nanoparticles of metallic Ag within the titanate coating. The surfaces generated with all combinations of AgNO3 and Ga(NO3)3 concentrations show bioactivity. The bacterial assay confirms a strong bactericidal impact achieved by the effect of both Ga and Ag present on the surface, especially for Pseudomonas aeruginosa, one of the main pathogens involved in orthopedic implant failures. SaOS-2 cells adhere and proliferate on the Ga/Ag-doped Ti surfaces, and the presence of gallium favors cell differentiation. The dual effect of both metallic agents doping the titanium surface provides bioactivity while protecting the biomaterial from the most frequent pathogens in implantology.

Boron nitride nanofiber/Zn-doped hydroxyapatite/polycaprolactone scaffolds for bone tissue engineering applications.

In this study, Zn doped hydroxyapatite (Zn HA)/boron nitride nanofiber (BNNF)/poly-ε-caprolactone (PCL) composite aligned fibrous scaffolds are produced with rotary jet spinning (RJS) for bone tissue engineering applications. It is hypothesized that addition of Zn HA and BNNF will contribute to cell viability as well as mechanical and osteogenic properties of the PCL scaffolds. Zn HA was synthesized by mixing Ca and P sources followed by sonication and aging whereas BNNF was obtained by the reaction of melamine with boric acid followed by freeze-drying for annealing of fibers. It is found that incorporation of both Zn HA and BNNF in PCL fibers resulted in higher calcium phosphate (CaP) precipitation on the scaffolds. Also, in vitro cell culture studies showed that presence of both Zn HA and BNNF also had synergistic effect for enhanced proliferation and osteogenic activity of Saos-2 cells. Mechanical properties of PCL-Zn HA-BNNF were found similar to that of non-load bearing bones. Furthermore, the presence of Zn HA and BNNF had synergistic effects to cell attachment, proliferation and spreading without causing cytotoxic effect on cells. The highest ALP activity was obtained in the PCL-Zn HA- BNNF group at days 7 and 14 due to release of zinc, calcium, phosphate and boron. Considering its mechanical and bioactivity properties, PCL-Zn HA-BNNF composite scaffolds hold promise as non-load bearing bone substitutes.

TRIM4 Expression Related to Malignant Progression and Cisplatin Resistance in Osteosarcoma.

Osteosarcoma (OS) is a high-grade intraosseous malignancy. Twenty to thirty percent of OS patients react poorly to standard therapy with a combination of surgical resection and chemotherapy. It is necessary to find molecules that play an important role in this. This study explored the role of TRIM4 in OS chemotherapy sensitivity and malignant progression. The expression of TRIM4 in OS tissues and cells was examined by RT-qPCR, immunohistochemical staining, and western blot. Specific siRNA was transfected into U2-OS and SAOS2 cells to target TRIM4. Cell biological behavior was examined by CCK-8, Transwell, and flow cytometry experiments. Cisplatin-resistant SAOS2 (SAOS2-Cis-R) cells were established, and the effect of TRIM4 expression on the cisplatin response of SAOS2 cells was tested. Knockdown of TRIM4 significantly inhibited the proliferation, migration, and invasion of U2-OS and SAOS2 cells and induced apoptosis. TRIM4 expression was significantly higher in chemotherapy-resistant OS tissues compared to chemotherapy-sensitive OS tissues. Furthermore, the expression of TRIM4 in SAOS2-Cis-R cells was significantly increased compared to parental SAOS2 cells. Moreover, overexpression of TRIM4 enhanced cisplatin resistance in parental SAOS2 cells, while the downregulation of TRIM4 expression enhanced cisplatin sensitivity of SAOS2-Cis-R cells. High TRIM4 expression might be associated with malignant progression and poor response to chemotherapy response of OS. Targeting TRIM4 may be beneficial for OS treatment or combination therapy.

Improved osteogenic activity of NiTi orthopedic implant by HAp-Nb2O5 composite coatings: Materials and biological points of view

The surface properties of NiTi, as an interface between the synthetic implant and living tissue, play a vital role in guaranteeing implantation success, especially during the initial stage. This contribution endeavors to enhance the surface features of NiTi orthopedic implants through the application of HAp-based coatings, placing emphasis on assessing the influence of Nb2O5 particles concentration in the electrolyte on resultant properties of HAp-Nb2O5 composite electrodeposits. The coatings were electrodeposited via pulse current mode under galvanostatic current control from an electrolyte containing 0–1 g/L of Nb2O5 particles. Surface morphology, topography, and phase composition were evaluated using FESEM, AFM, and XRD, respectively. EDS was employed to study surface chemistry. In vitro biomineralization and osteogenic activity of the samples were studied by immersing the samples in SBF and incubating them with osteoblastic SAOS-2 cells, respectively. The added Nb2O5 particles, at the optimum concentration, stimulated biomineralization, suppressed the Ni ion leaching, and improved SAOS-2 cell adhesion and proliferation. NiTi implant coated by HAp-0.50 g/L Nb2O5 layer showed tremendous osteogenic properties. Overall, the HAp-Nb2O5 composite layers bring forth fascinating coating in vitro biological performance, reducing Ni leaching, and promoting osteogenic activity, which are fundamental for the successful use of NiTi in vivo.

The Biocompatibility and Antibacterial Properties of the CNTs-Doped Magnesium Based Composite Implants in a Long-Term Biodegradation Process

The aim of this paper is to increase a new biodegradable implant material’s biodegradability, biocompatibility, and osteoinductivity in the long-term degradation process, as well as its antibacterial properties, novel carbon nanotubes (CNTs) with or without Cu element were doped into calcium phosphate (CaP)–chitosan (CS) layers and then fabricated to obtain the magnesium (Mg) matrix composites. In this paper, we investigated the influences of the CNTs-CaP-CS/Mg composites on proliferation and osteogenic differentiation of human osteosarcoma cell (SaOS-2) and human bone marrow mesenchymal stem cells (hBMSCs). Furthermore, the Cu/CNTs-CaP-CS/Mg was prepared to improve the bioactivity and antibacterial activity of the composites. The results indicated that CNTs-CaP-CS/Mg composites were suitable for proliferation and differentiation of SaOS-2 cells. Stimulated by the CNTs-CaP-CS/Mg extracts, the ALP expression of hBMSCs increased in the first 16 days and the mineralization ability of hBMSCs was highly expressed throughout the whole process which might be through the Erk1/2 signaling pathway. After CNTs-loaded Cu element, the bioactivity of the coating was satisfactory. Moreover, this new implant exhibited excellent antibacterial properties for Escherichia coli (E. coli) and Staphylococcus albus (S. albus). Collectively, these data suggest that the CNTs-CaP-CS/Mg and Cu/CNTs-CaP-CS/Mg might be potentially applied as bone implants for future clinical use.

Fabrication of succinate-alginate xerogel films for in vitro coupling of osteogenesis and neovascularization

The osseointegration of metallic implants is reliant on a cascade of molecular interactions and the delivery of macromolecules to the implant environment that occurs before substantial bone formation. Early blood vessel formation is a requisite first step in the healing timeline for osteoid formation, where vascular development can be accelerated as a result of controlled hypoxic conditioning. In this study, alginate-derived xerogel films containing varied concentrations of disodium succinate salt which has been shown to induce pseudohypoxia (short-term hypoxic effects while maintaining an oxygenated environment) were developed. Xerogels were characterized for their morphology, succinate release over time and cellular response with osteoblast-mimicking Saos-2 and human umbilical vein endothelial cells (HUVEC). Scanning electron microscopy revealed a multiscale topography that may favour osseointegration and alamarBlue assays indicated no cytotoxic effects during in vitro proliferation of Saos-2 cells. pH measurements of eluted succinate reach 95 % of peak value after 7 h of immersion for all gels containing 10 mM of succinate or less, and 60 % within the first 40 min. In vitro exposure of HUVECs to succinate-conditioned media increased the net concentration of total proteins measured by bicinchoninic acid (BCA) assay and maintains stable vascular endothelial growth factor (VEGF) and extracellular platelet-derived growth factor (PDGF) for vessel formation through comparison of enzyme-linked immunosorbent assays (ELISAs) of the culture media and cell lysate. Tube formation assays also showed a sustained increase in tube diameter across the first 48 h of HUVEC culture when succinate concentrations of 1 and 10 μM in the xerogel. Overall, the succinate-alginate films serve as a prospective organic coating for bone-interfacing implant materials which may induce temporary pseudohypoxic conditions favourable for early angiogenesis and bone regeneration in vivo at succinate concentrations of 1 or 10 μM.

Simultaneously stimulated osteogenesis and anti-bacteria of physically cross-linked double-network hydrogel loaded with MgO-Ag2O nanocomposites

Hydrogels, with a three-dimensional network of water-soluble polymer and water, could simulate the critical properties of extracellular matrix, which has been widely used in bone tissue engineering. However, most of conventional hydrogels for bone regeneration are fragile and have poor osteogenic activity, which restricts their applications. In this work, a novel nanoparticle-hydrogel composite consisting of physically cross-linked double-network loaded with MgO-Ag2O nanocomposites was developed by the sol-gel method. The Mg2+ released from MgO-Ag2O nanocomposites was used as an ionic cross-linking site of sodium alginate (SA), while the hydrophobic micelles in the polyacrylamide (PAAM) network is acted as another crosslinking point. The results indicated that the novel nanoparticle-hydrogel composites had good self-recovery ability and excellent mechanical properties compared with the conventional sodium alginate (SA)/polyacrylamide (PAAM) hydrogels. Additionally, it showed a slow release of Mg and Ag ions due to the dual function of the embedding effect of hydrogels and the increasing pH of the solution induced by the hydrolysis of sodium alginate. In terms of in vitro tests, the nanoparticle-hydrogel composites showed significantly stimulatory effects on the proliferation and differentiation of SaOS-2 cells. In addition, the antibacterial effects of the nanoparticle-hydrogel composites were gradually enhanced with the increase of MgO-Ag2O content.