Bone Osteosarcoma Cells Research Articles

The comparison of extracellular vesicles with matrix vesicles derived from human vascular smooth muscle versus bone osteoblastic and osteosarcoma cells

The comparison of extracellular vesicles with matrix vesicles derived from human vascular smooth muscle versus bone osteoblastic and osteosarcoma cells

Live Cell Protein Imaging of Tandem Complemented-GFP11-Tagged Coiled-Coil Domain-Containing Protein-124 Identifies this Factor in G3BP1-Induced Stress-Granules.

Coiled-coil domain-containing 124 protein is a multifunctional RNA-binding factor, and it was previously reported to interact with various biomolecular complexes localized at diverse subcellular locations, such as the ribosome, centrosome, midbody, and nucleoli. We aimed to better characterize the subcellular CCDC124 translocation by labelling this protein with a fluorescent tag, followed by laser scanning confocal microscopy methods. As traditional GFP-tagging of small proteins such as CCDC124 often faces limitations like potential structural perturbations of labeled proteins, and interference of the fluorescent-tag with their endogenous cellular functions, we aimed to label CCDC124 with the smallest possible split-GFP associated protein-tagging system (GFP11/GFP1-10) for better characterization of its subcellular localizations and its translocation dynamics. By recombinant DNA techniques we generated CCDC124-constructs labelled with either single of four tandem copies of GFP11 (GFP11 × 1::CCDC124, GFP11 × 4::CCDC124, or CCDC124::GFP11 × 4). We then cotransfected U2OS cells with these split-GFP constructs (GFP11 × 1(or X4)::CCDC124/GFP1-10) and analyzed subcellular localization of CCDC124 protein by laser scanning confocal microscopy. Tagging CCDC124 with four tandem copies of a 16-amino acid short GFP-derived peptide-tag (GFP11 × 4::CCDC124) allowed better characterization of the subcellular localization of CCDC124 protein in our model human bone osteosarcoma (U2OS) cells. Thus, by this novel methodology we successfully identified GFP11 × 4::CCDC124 molecules in G3BP1-overexpression induced stress-granules by live cell protein imaging for the first time. Our findings propose CCDC124 as a novel component of the stress granule which is a membraneless organelle involved in translational shut-down in response to cellular stress.

In vitro Molecular Mechanisms of Anticancer Activity of Stevioside in Human Osteosarcoma Cell Lines (Sarcoma Osteogenic)

Abstract Introduction: Osteosarcoma (OS) is a rare and aggressive form of bone cancer that primarily affects the long bones of the body, such as the arms and legs. It is characterized by the uncontrolled growth of malignant cells in the bone tissue, leading to the formation of abnormal and painful bone masses. Steviol glycosides have been widely used as natural noncalorie sweeteners and are the collective name of the sweet substances found naturally in the plant Stevia rebaudiana, which is commonly called Stevia. Our study aimed to analyze the anticancer activity of Stevioside in OS. Materials and Methods: Stevioside was applied to OS cells, and the levels of Bcl xL, Bcl-2, and Bax were then estimated. The results of three separate studies, each carried out in triplicate, were expressed as the mean ± standard errors of the mean (SEM). One-way ANOVA was used for statistical analysis. Results: The findings showed that the effect of Stevioside on sarcoma osteogenic cells with mean ± SEM as 0.74 ± 0.05, 0.69 ± 0.09, 0.46 ± 0.09 for Bcl-xL gene, 0.98 ± 0.06, 0.58 ± 0.07, 0.5 ± 0.07 for Bcl-2 gene, and 1.2 ± 0.08, 1.45 ± 0.11, 1.67 ± 0.12 for Bax gene, respectively, when treated with untreated control cells. Conclusion: The study concludes its action against bone OS cells was significant with apoptotic induction. Stevia has a wide range of health benefits as well as being a plant-based diet it has less of side effects and promoting features even by intaking it daily along with other medicines.

Bifunctional mesoporous glasses for bone tissue engineering: Biological effects of doping with cerium and polyphenols in 2D and 3D in vitro models

This study evaluates the cytocompatibility of cerium-doped mesoporous bioactive glasses (Ce-MBGs) loaded with polyphenols (Ce-MBGs-Poly) for possible application in bone tissue engineering after tumour resection. We tested MBGs powders and pellets on 2D and 3D in vitro models using human bone marrow-derived mesenchymal stem cells (hMSCs), osteosarcoma cells (U2OS), and endothelial cells (EA.hy926). Promisingly, at a low concentration in culture medium, Poly-loaded MBGs powders containing 1.2 mol% of cerium inhibited U2OS metabolic activity, preserved hMSCs viability, and had no adverse effects on EA.hy926 migration. Moreover, the study discussed the possible interaction between cerium and Poly, influencing anti-cancer effects. In summary, this research provides insights into the complex interactions between Ce-MBGs, Poly, and various cell types in distinct 2D and 3D in vitro models, highlighting the potential of loaded Ce-MBGs for post-resection bone tissue engineering with a balance between pro-regenerative and anti-tumorigenic activities.

Label-Free, Noninvasive Bone Cell Classification by Hyperspectral Confocal Raman Microscopy.

Characterizing and identifying cells in multicellular in vitro models remain a substantial challenge. Here, we utilize hyperspectral confocal Raman microscopy and principal component analysis coupled with linear discriminant analysis to form a label-free, noninvasive approach for classifying bone cells and osteosarcoma cells. Through the development of a library of hyperspectral Raman images of the K7M2-wt osteosarcoma cell lines, 7F2 osteoblast cell lines, RAW 264.7 macrophage cell line, and osteoclasts induced from RAW 264.7 macrophages, we built a linear discriminant model capable of correctly identifying each of these cell types. The model was cross-validated using a k-fold cross validation scheme. The results show a minimum of 72% accuracy in predicting cell type. We also utilize the model to reconstruct the spectra of K7M2 and 7F2 to determine whether osteosarcoma cancer cells and normal osteoblasts have any prominent differences that can be captured by Raman. We find that the main differences between these two cell types are the prominence of the β-sheet protein secondary structure in K7M2 versus the α-helix protein secondary structure in 7F2. Additionally, differences in the CH2 deformation Raman feature highlight that the membrane lipid structure is different between these cells, which may affect the overall signaling and functional contrasts. Overall, we show that hyperspectral confocal Raman microscopy can serve as an effective tool for label-free, nondestructive cellular classification and that the spectral reconstructions can be used to gain deeper insight into the differences that drive different functional outcomes of different cells.

Cellular uptake and fate of cationic polymer-coated nanodiamonds delivering siRNA: a mechanistic study.

Gene silencing using small interfering RNAs (siRNAs) is a selective and promising approach for treatment of numerous diseases. However, broad applications of siRNAs are compromised by their low stability in a biological environment and limited ability to penetrate cells. Nanodiamonds (NDs) coated with cationic polymers can enable cellular delivery of siRNAs. Recently, we developed a new type of ND coating based on a random copolymer consisting of (2-dimethylaminoethyl) methacrylate (DMAEMA) and N-(2-hydroxypropyl) methacrylamide (HPMA) monomers. These hybrid ND-polymer particles (Cop+-FND) provide near-infrared fluorescence, form stable complexes with siRNA in serum, show low toxicity, and effectively deliver siRNA into cells in vitro and in vivo. Here, we present data on the mechanism of cellular uptake and cell trafficking of Cop+-FND : siRNA complexes and their ability to selectively suppress mRNA levels, as well as their cytotoxicity, viability and colloidal stability. We identified clathrin-mediated endocytosis as the predominant entry mechanism for Cop+-FND : siRNA into U-2 OS human bone osteosarcoma cells, with a substantial fraction of Cop+-FND : siRNA following the lysosome pathway. Cop+-FND : siRNA potently inhibited the target GAPDH gene with negligible toxicity and sufficient colloidal stability. Based on our results, we suggest that Cop+-FND : siRNA can serve as a suitable in vivo delivery system for siRNA.

Production of an eco-friendly, effective antimicrobial and antifungal from cerium/natural bio-hydroxyapatite coating for titanium plates suitable for bone augmentation

As a promising technique for rebuilding bone defects, materials having enhanced osteoductivity and antimicrobial and fungi effects have been used for bone replacement. Accordingly, the present study aims to develop a sintered titanium (Ti) plate prepared by the cold isostatic press (CIP) coated with nano bio-natural hydroxyapatite (n-HA) via freeze-drying technique for bone substitution. Moreover, the influence of cerium chloride heptahydrate doping with different concentrations of 0.5, 2, and 8 wt% was evaluated for enhancing the osteogeneration process and antibacterial activity on titanium (Ti) plates instead of antibiotic-loaded. Physical properties showed that the n-HA/2%CeCl3 coat is the most suitable concentration with an appropriate porosity of 73.43 ± 3.52 compared to porous n-HA coating Ti plate with a porosity of 90.38 ± 0.27. The biological activity (in-vitro) study in terms of following up the apatite nucleation on the blank Ti plate and Ti/n-HA/2 % CeCl3 surfaces after immersions in SBF for up to 28 days showed the formation of spherical clusters from carbonated apatite particles on the sample's surface, with a Ca/P ratio equal to 2.26. The cytotoxicity test was examined using a bone osteosarcoma cell line (HOS). The final results confirmed minimal cytotoxicity for the plate coated with n-HA/2 % CeCl3 (3.6 %). Cell attachment results indicate the potential of the cells to adhere and spread on the surface. In addition, the antimicrobial assessment of n-HA/2 % CeCl3 coated Ti plates showed broad-spectrum activity against not only the gram-positive or gram-negative but also fungal ones.

3D-Printed Collagen-Nanocellulose Hybrid Bioscaffolds with Tailored Properties for Tissue Engineering Applications.

Hybrid collagen (Coll) bioscaffolds have emerged as a promising solution for tissue engineering (TE) and regenerative medicine. These innovative bioscaffolds combine the beneficial properties of Coll, an important structural protein of the extracellular matrix, with various other biomaterials to create platforms for long-term cell growth and tissue formation. The integration or cross-linking of Coll with other biomaterials increases mechanical strength and stability and introduces tailored biochemical and physical factors that mimic the natural tissue microenvironment. This work reports on the fabrication of chemically cross-linked hybrid bioscaffolds with enhanced properties from the combination of Coll, nanofibrillated cellulose (NFC), carboxymethylcellulose (CMC), and citric acid (CA). The bioscaffolds were prepared by 3D printing ink containing Coll-NFC-CMC-CA followed by freeze-drying, dehydrothermal treatment, and neutralization. Cross-linking through the formation of ester bonds between the polymers and CA in the bioscaffolds was achieved by exposing the bioscaffolds to elevated temperatures in the dry state. The morphology, pores/porosity, chemical composition, structure, thermal behavior, swelling, degradation, and mechanical properties of the bioscaffolds in the dry and wet states were investigated as a function of Coll concentration. The bioscaffolds showed no cytotoxicity to MG-63 human bone osteosarcoma cells as tested by different assays measuring different end points. Overall, the presented hybrid Coll bioscaffolds offer a unique combination of biocompatibility, stability, and structural support, making them valuable tools for TE.

Investigation of the efficacy of epidermal growth factor, boric acid and their combination in cartilage injury in rats: An experimental study.

In this study, we aimed to determine the bioefficacy of epidermal growth factor (EGF), boric acid (BA), and their combination on cartilage injury in rats. In in vitro setting, the cytotoxic effects of BA, EGF, and their combinations using mouse fibroblast cell (L929), human bone osteosarcoma cell (Saos-2), and human adipose derived mesenchymal stem cells (hAD-MSCs) were determined by applying MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] test. In in vivo setting, 72 rats were randomly divided into four groups. A standard chondral defect was created and microfracture was performed in all groups. Group A was determined as the control group. In addition to the standard procedure, Group B received 100 ng/mL of EGF, Group C received a combination of 100 ng/mL of EGF and 10 µg/mL of BA combination, and Group D 20 µg/mL of BA. The cytotoxic effect of the combinations of EGF dilutions (1, 5, 10, 25, 50, 100, 200 ng/mL) with BA (100, 300, 500 µg/mL) was observed only in the 72-h application period and in Saos-2. The cytotoxic effect of BA was reduced when combined with EGF. There was no significant difference in the histopathological scores among the groups (p=0.13). Our study showed that EGF and low-dose BA application had a positive effect on cartilage healing in rats. Significant decreases in recovery scores were observed in the other groups. The combination of EGF and BA promoted osteoblast growth. Detection of lytic lesions in the group treated with 20 µg/mL of BA indicates that BA may have a cytotoxic effect.

Radiolabeling, Quality Control, and Cell Binding Studies of New 99mTc-Labeled Bisphosphonates: 99mTc-Ibandronate Sodium.

Early detection of bone cancer is critical for treating symptoms, minimizing pain, and increasing overall quality of life. It is critical to develop novel radiopharmaceuticals with high labeling efficiency and stability for the diagnosis of bone cancer. This research aims to design a novel radiopharmaceutical that may be used to diagnose bone cancer. In this study, ibandronate sodium (IBD), a bisphosphonate analog, was radiolabeled with technetium-99m [99mTc] and quality control tests on the newly developed radiopharmaceutical ([99mTc]Tc-IBD) were performed using radioactive thin layer chromatography. After that, the incorporation of [99mTc]Tc-IBD into hydroxyapatite (HA) crystals and a human bone osteosarcoma cell line (U2OS) was tested. According to the results obtained, optimal radiolabeling procedure was obtained for [99mTc]Tc-IBD with 200 μg.mL-1 IBD, 20 μg stannous chloride, and 99mTc with 37 MBq radioactivity. The reaction mixture was adjusted to pH 5.5 and incubated at room temperature for 15 min. The radiochemical purity of [99mTc]Tc-IBD was found to be greater than 95% at room temperature for up to 6 h. Additionally, chromatography analysis showed >95% [99mTc]Tc-IBD complex formation with promising stability for up to 24 h in saline and up to 2 h in cell medium. The percentage binding of IBD to HA was 83.70 ± 3.67 and the logP of [99mTc]Tc-IBD was -1.1014. The radiolabeled complex exhibited a higher rate of cell incorporation to U2OS cells compared to Reduced/Hydrolyzed 99mTcO4 -. The newly produced radiopharmaceutical is very promising according to the results of in vitro cell culture, HA binding, and quality studies, and will be a step forward for further studies in nuclear medicine for bone cancer diagnostics.

Thiram, an inhibitor of 11ß-hydroxysteroid dehydrogenase type 2, enhances the inhibitory effects of hydrocortisone in the treatment of osteosarcoma through Wnt/β-catenin pathway

BackgroundThe anti-osteosarcoma effects of hydrocortisone and thiram, an inhibitor of type 2 11ß-hydroxysteroid dehydrogenase (11HSD2), have not been reported. The purpose of this study was to investigate the effects of hydrocortisone alone or the combination of hydrocortisone with thiram on osteosarcoma and the molecular mechanism, and determine whether they can be as new therapeutic agents for osteosarcoma.MethodsNormal bone cells and osteosarcoma cells were treated with hydrocortisone or thiram alone or in combination. The cell proliferation, migration, cell cycle and apoptosis were detected by using CCK8 assay, wound healing assay, and flow cytometry, respectively. An osteosarcoma mouse model was established. The effect of drugs on osteosarcoma in vivo was assessed by measuring tumor volume. Transcriptome sequencing, bioinformatics analysis, RT–qPCR, Western blotting (WB), enzymelinked immunosorbent assay (ELISA) and siRNA transfection were performed to determine the molecular mechanisms.ResultsHydrocortisone inhibited the proliferation and migration, and induced apoptosis and cell cycle arrest of osteosarcoma cells in vitro. Hydrocortisone also reduced the volume of osteosarcoma in mice in vivo. Mechanistically, hydrocortisone decreased the levels of Wnt/β-catenin pathway-associated proteins, and induced the expression of glucocorticoid receptor α (GCR), CCAAT enhancer-binding protein β (C/EBP-beta) and 11HSD2, resulting in a hydrocortisone resistance loop. Thiram inhibited the activity of the 11HSD2 enzyme, the combination of thiram and hydrocortisone further enhanced the inhibition of osteosarcoma through Wnt/β-catenin pathway.ConclusionsHydrocortisone inhibits osteosarcoma through the Wnt/β-catenin pathway. Thiram inhibits 11HSD2 enzyme activity, reducing hydrocortisone inactivation and promoting the effect of hydrocortisone through the same pathway.

Smartphone assisted fluorescent-colorimetric probe for bismuth (III) ion and potential applications

A new dual fluorescent-colorimetric probe (E)-4-methyl-N'-((2,3,6,7-tetrahydro-1H,5H-pyrido[3,2,1-ij]quinolin-9-yl)methylene)benzenesulfonohydrazide (L) was synthesized by condensation reaction of julolidine carboxaldehyde and p-toluene sulfonyl hydrazide to get the probe (L) for recognition of bismuth ions (Bi3+). The structural conformation of L was confirmed through 1H NMR, IR, and mass spectral analysis. The probe L showed visual color change and turn-on emission upon interaction with Bi3+ in H2O:CH3CN (7:3, v/v) media over other divalent and trivalent metal ions. The probe displays selective ‘turn-on’ emission for Bi3+via chelation enhanced fluorescence (CHEF) and > CN isomerization mechanism. The experimental analysis of Job’s plot showed a 2:1 stoichiometric ratio of L-Bi3+ complex formation and this was further verified with theoretical studies. The detection limit by spectrophotometric and spectrofluorometric were found to be 170 nM and 6.39 nM, respectively. The binding mechanism was verified by 1H NMR, ESI-mass, and theoretical studies. Furthermore, the selective colour change of L with Bi3+ was integrated with a smartphone to monitor the change in the RGB tool and test paper kit. The turn-on response of the probe with Bi3+ was used to capture by the fluorescence imaging technique in live Human Bone Osteosarcoma cell line (HOS) cells. Overall, probe L demonstrates a promising potential for the detection of Bi3+ ions in the protic environment and this is the first report of a fluorescent probe used in HOS cell live imaging.

Fabrication of mesoporous zirconia and titania nanomaterials for bone regeneration and drug delivery applications

Mesoporous materials have reached a significant milestone in the last twenty years in the field of drug delivery, and they continue to be an important part of development and innovation in pharmacodynamics and pharmacokinetics. In addition, their applications in the regeneration of hard tissues were greatly explored in recent decades due to their exponential biomineralization capabilities. They are the perfect candidates for active uptake and loading medicinal substances due to their unique chemical-physical properties. In this research, mesoporous zirconia (MZNs) and titania (MTNs) nanopowders were prepared by polymer sacrificial method as amoxicillin delivery systems. They were investigated using several characterization techniques including X-rays diffraction (XRD), Fourier transform infrared (FTIR), Transmittance electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) surface area measurements. These techniques assist in evaluating the appropriate pore size and diameter, with emphasis on the safety of the released drugs. Amoxicillin release form MZNs and MTNs was conducted in Phosphate buffer saline (PBS) up to 28 days. The possibility of using these antibacterial agents against different strains of gram-positive and gram-negative bacteria has been evaluated. Finally viabilities of the human bone osteosarcoma cell line (MG-63) were tested. MZNs and MTNs demonstrate particle diameters in range of (8–25 nm) and they were confirmed as mesoporous particles by TEM and BET techniques. Amoxicillin loaded nanopowders showed good antibacterial and antifungal activities alongside with proliferation behavior after 24 h (124 and 110%) for MZNs & MTNs, respectively, and (189 and 114%) for amoxicillin loaded MZNs & MTNs, respectively. Therefore, the developed nanomaterials are of high potentiality to be implemented as medication delivery systems for bone regeneration.

The Influence of Plasma Treatment on the Corrosion and Biocompatibility of Magnesium.

In our study, plasma surface modification was employed to tailor the surface properties of magnesium in terms of surface chemistry, topography, and wettability. For two sets of samples, the plasma treatment involved two steps using two different gases (hydrogen and oxygen), while one set of samples was treated with one step only using oxygen. X-ray photoelectron spectroscopy (XPS) was applied to determine the surface composition, oxidation state of the elements, and the thickness of the surface oxide layer on the Mg samples after different plasma treatments. The surface morphology was characterised using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The wettability was analysed by measuring the static water-contact angles and the corrosion was evaluated using potentiodynamic measurements. The interaction of the live cells with the differently modified Mg surfaces was evaluated in terms of biocompatibility using MG-63 cells (human bone osteosarcoma cells). We have shown that a plasma surface treatment significantly decreased the carbon content and the formation of a 15–20-nm-thick MgO layer was observed. This improves the corrosion resistance, while the biocompatibility was retained, compared to the untreated Mg. A plasma surface treatment is therefore an important step in the development of novel surfaces with improved corrosion resistance for magnesium in biomedical applications.

Evaluation of Three ISO Estrogen Receptor Transactivation Assays Applied to 52 Domestic Effluent Samples.

Estrogens are released to the aquatic environment by wastewater treatment plant (WWTP) effluents and can affect wildlife. In the last three decades, many in vitro assay platforms have been developed to detect and quantify estrogenicity in water. In 2018, the International Organization for Standardization (ISO) standardized protocols became available for three types of in vitro estrogen receptor transactivation assays (ERTAs) detecting estrogenicity in 96-well plates (ISO19040 1-3). Two ERTAs-lyticase Yeast Estrogen Screen (L-YES) and Arxula YES (A-YES)-use genetically modified yeast strains, whereas the third utilizes stably transfected human cells. One human cell based assay is ERα-CALUX, which is based on a genetically modified human bone osteosarcoma cell line. In the present study, we characterized the performance, comparability, and effectiveness of these three ERTAs, including an evaluation involving proposed water quality thresholds (effect-based trigger values [EBTs]). For a robust evaluation, we collected 52 effluent samples over three sampling campaigns at 15 different WWTPs in Switzerland. Estrogen receptor transactivation assay results were correlated and compared with results from chemical analysis targeting known estrogens. The three ERTAs showed comparable data over all campaigns. However, the selection of EBTs plays a significant role in the interpretation and comparison of bioassay resultsto distinguish between acceptable and unacceptable water quality. Applying a fixed cross-assay EBT for effluent of 4 ng L-1 resulted in varying numbers of threshold exceedances ranging between zero and four samples depending on the ERTA used. Using assay-specific EBTs showed exceedances in eight samples (ERα-CALUX) and in one sample (A-YES), respectively. Thus, proposed EBTs do not produce similar risk profiles across samples and further refinement of assay-specific EBTs is needed to account for assay-specific differences and to enable the application of ERTAs as effect-based methods in environmental monitoring. Environ Toxicol Chem 2022;41:2512-2526. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Block copolymer nanopatterns affect cell spreading: Stem versus cancer bone cells

Bone healing after a tumor removal can be promoted by biomaterials that enhance the bone regeneration and prevent the tumor relapse. Herein, we obtained several nanopatterns by self-assembly of polystyrene-block-poly-(2-vinylpyridine) (PS-b-P2VP) with different molecular weights and investigated the adhesion and morphology of human bone marrow mesenchymal stem cells (BMMSC) and osteosarcoma cell line (SaOS-2) on these patterns aiming to identify topography and chemistry that promote bone healing. We analyzed > 2000 cells per experimental condition using imaging software and different morphometric descriptors, namely area, perimeter, aspect ratio, circularity, surface/area, and fractal dimension of cellular contour (FDC). The obtained data were used as inputs for principal component analysis, which showed distinct response of BMMSC and SaOS-2 to the surface topography and chemistry. Among the studied substrates, micellar nanopatterns assembled from the copolymer with high molecular weight promote the adhesion and spreading of BMMSC and have an opposite effect on SaOS-2. This nanopattern is thus beneficial for bone regeneration after injury or pathology, e.g. bone fracture or tumor removal.

Selective chromogenic and fluorogenic signalling of Hg2+ ions using a benzothiazole-quinolinyl acrylate conjugate and its applications in the environmental water samples and living cells

We have developed a new chromogenic and fluorogenic chemosensor (L) based on benzothiazole conjugated with quinolinyl acrylate for the detection of Hg2+ ions with excellent selectivity and sensitivity. In the presence of Hg2+, the fluorescence of L was quenched from light blue to colorless. The L could work in the wide pH range of 5.0–8.0 without considerable interference from other tested ions. UV–Visible and fluorometric investigations revealed that the limit of detection (LOD) for Hg2+ was 1.0 μM (202 ppb) and 11.8 nM (2.38 ppb), respectively. Further, the applicability of probe L in the determination of Hg2+ in various water samples and biological samples were tested. Human Bone Osteosarcoma cell lines (HOS) were utilized for this study and satisfying results were obtained. These cell line results also further support the ‘on-off’ properties of probe L. Based on the colorimetric and fluorescent results we have designed a Boolean logic gate for futuristic applications.

Vancomycin Containing PDLLA and PLGA/β-TCP Inhibit Biofilm Formation but Do Not Stimulate Osteogenic Transformation of Human Mesenchymal Stem Cells.

AimsChronic osteomyelitis, including implant-related prosthetic joint infection, is extremely difficult to cure. We develop vancomycin containing release systems from poly(d,l-lactide) (PDLLA) and poly(d,l-lactide-co-glycolide) (PLGA) composites with beta-tricalcium phosphate (β-TCP) to treat methicillin-resistant Staphylococcus aureus osteomyelitis. We ask whether vancomycin containing PDLLA/β-TCP and PLGA/β-TCP composites will prevent early biofilm formation, allow cell proliferation and osteogenic differentiation, and stimulate osteogenic signaling molecules in the absence of an osteogenic medium.MethodsComposites were produced and characterized with scanning electron microscopy. In vitro vancomycin release was assessed for 6 weeks. Biofilm prevention was calculated by crystal violet staining. Human bone marrow-derived mesenchymal stem cells (hBM-MSCs) and osteosarcoma cell (SaOS-2) proliferation and differentiation were assessed with water soluble tetrazolium salt and alkaline phosphatase (ALP) staining. Real-time quantitative polymerase chain reaction defined osteogenic signaling molecules for hBM-MSCs.ResultsTotally, 3.1 ± 0.2 mg and 3.4 ± 0.4 mg vancomycin released from PDLLA/β-TCP and the PLGA/β-TCP composites, respectively, and inhibited early biofilm formation. hBM-MSCs and SaOS-2 cells proliferated on the composites and stimulated ALP activity of cells. Runt-related transcription factor 2 (RUNX2) and SRY-Box transcription Factor 9 (SOX9) expressions were, however, lower with composites when compared with control.ConclusionVancomycin containing PDLLA/β-TCP and PLGA/β-TCP composites inhibited early biofilm formation and proliferated and differentiated hBM-MSCs and SaOS-2 cells, but osteogenesis-related RUNX2 and SOX9 transcription factors were not strongly expressed in the absence of an osteogenic medium for 14 days.

Zinc substituted hydroxyapatite/silk fiber/methylcellulose nanocomposite for bone tissue engineering applications

Fibrous bio-composite based on silk fiber (SF), methylcellulose (MC) and zinc substituted hydroxyapatite (ZnxCa5-x (PO4)3(OH) (x = 0.1, 0.2, 0.5 and 1.0)) were obtained with the use of electrospinning (E-Spin) method. XRD, FTIR, SEM-EDAX, swelling, porosity and mechanical properties of the composites were analyzed. The elongation at break (%) (20.97–317.20 %) and tensile strength (29.85–110.92 MPa) of nanocomposites was increased with an increase in the wt% of Zn-HAP in SF/MC. An increase in the zone of inhibition with an increase in the wt% of Zn-HAP into the SF/MC was observed against E. coli (34 ± 0.33 to 47 ± 1.15), S. aureus (28 ± 0.24 to 38 ± 1.32) and C. albicans (24 ± 0.36 to 39 ± 2.36). The in-vitro biomineralization study using SBF (simulated body fluid) showed apatite layer formation on the nano-composite. In addition, the optimized (20 wt % of Zn1.0Ca4.0(PO4)3(OH)/SF/MC) nano-composite showed good cell viability against human bone osteosarcoma (MG-63) cells.

Facile One-Pot Method for All Aqueous Green Formation of Biocompatible Silk Fibroin-Poly(Ethylene Oxide) Fibers for Use in Tissue Engineering.

Silk fibroin (SF) fibers are highly regarded in tissue engineering because of their outstanding biocompatibility and tunable properties. A challenge remains in overcoming the trade-off between functioning and biocompatible fibers and the use of cytotoxic, environmentally harmful organic solvents in their processing and formation. The aim of this research was to produce biocompatible SF fibers without the use of cytotoxic solvents, via pressurized gyration (PG). Aqueous SF was blended with poly(ethylene oxide) (PEO) in ratios of 80:20 (labeled SF-PEO 80:20) and 90:10 (labeled SF-PEO 90:10) and spun into fibers using PG, assisted by a range of applied pressures and heat. Pure PEO (labeled PEO-Aq) and SF solubilized in hexafluoro-isopropanol (HFIP) (labeled SF-HFIP) and aqueous SF (labeled SF-Aq) were also prepared for comparison. The resulting fibers were characterized using SEM, TGA, and FTIR. Their in vitro cell behavior was analyzed using a Live/Dead assay and cell proliferation studies with the SaOS-2 human bone osteosarcoma cell line (ATCC, HTB-85) and human fetal osteoblast cells (hFob) (ATCC, CRL-11372) in 2D culture conditions. Fibers in the micrometer range were successfully produced using SF-PEO blends, SF-HFIP, and PEO-Aq. The fiber thickness ranged from 0.71 ± 0.17 μm for fibers produced using SF-PEO 90:10 with no applied pressure to 2.10 ± 0.78 μm for fibers produced using SF-PEO 80:10 with 0.3 MPa applied pressure. FTIR confirmed the presence of SF via amide I and amide II bands in the blend fibers because of a change in structural conformation. No difference was observed in thermogravimetric properties among varying pressures and no significant difference in fiber diameters for pressures. SaOS-2 cells and hFOb cell studies demonstrated higher cell densities and greater live cells on SF-PEO blends when compared to SF-HFIP. This research demonstrates a scalable and green method of producing SF-based constructs for use in bone-tissue engineering applications.