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Abstract Background Angiogenesis, the formation of new blood vessels, has become an important target in cancer therapy. Angiogenesis plays an important role in tumor growth and metastasis. Koetjapic acid (KA) is a seco-A-ring oleanene triterpene isolated from S. koetjape. The solvent extract of this plant species was shown previously to have strong antiangiogenic activity; however the active ingredient(s) that conferred the biological activity and the mode of action was not established. Given the high concentration of KA in S. koetjape, an attempt has been made in this study to investigate the antiangiogenic properties of KA. Results Treatment with 10-50 μg/ml KA resulted in dose dependent inhibition of new blood vessels growth in ex vivo rat aortic ring assay. KA was found to be non-cytotoxic against HUVECs with IC50 40.97 ± 0.37 μg/ml. KA inhibited major angiogenesis process steps, endothelial cell migration and differentiation as well as VEGF expression. Conclusions The non-cytotoxic compound, KA, may be a potent antiangiogenic agent; its activity may be attributed to inhibition of endothelial cells migration and differentiation as well VEGF suppression.

We used wet treatment to immobilize luminescent silicon nanoparticles on industrial glass fibers to impart optical and chemical functions to the fiber. Carpets or pads consisting of thousands of fibers are processed in parallel, enhancing the sensitivity of detection and the sampled volume. Treated pads exhibit strong luminescence, characteristic of the luminescence of the particles; showing no shift, broadening, or reduction of quantum efficiency. We demonstrate that drawing material by the pad due to physical adsorption can be reversed. We also demonstrate that allylamine can be covalently attached by photoinduced irradiation reactions, which results in imprinting the amine emission spectrum, providing spectral recognition. The imprint accompanied with a blue-shifting of the luminescence spectrum of the probe, allowing examination of the effect of termination on the nanoparticle structure. The shift is found to be consistent with an increase in the bandgap of the Si nanoparticle and is consistent with Quantum Monte Carlo calculations. In addition to sampling, the nano probe pad has the potential to enable a variety of biomedical applications through subsequent attachment. [ABSTRACT FROM AUTHOR]

The work describes a fluorescence-based study formapping the highest affinity truncated aptamer from the full length sequence and its integration in a graphene oxide platform for the detection of Salmonella enteriditis. To identify the best truncated sequence, molecular beacons and a displacement assay design are applied. In the fluorescence displacement assay, the truncated aptamer was hybridized with fluorescein and quencher-labeled complementary sequences to form a fluorescence/quencher pair. In the presence of S. enteritidis, the aptamer dissociates from the complementary labeled oligonucleotides and thus, the fluorescein/quencher pair becomes physically separated. This leads to an increase in fluorescence intensity. One of the truncated aptamers identified has a 2- fold lower dissociation constant (3.2 nM) compared to its full length aptamer (6.3 nM). The truncated aptamer selected in this process was used to develop a fluorometric graphene oxide (GO) based assay. If fluorescein-labeled aptamer is adsorbed on GO via π stacking interaction, fluorescence is quenched. However, in the presence of target (S. enteriditis), the labeled aptamers is released from surface to form a stable complex with the bacteria and fluorescence is restored, depending on the quantity of bacteria being present. The resulting assay has an unsurpassed detection limit of 25 cfu⋅mL-1 in the best case. The cross reactivity to Salmonella typhimurium, Staphylococcus aureus and Escherichia coli is negligible. The assay was applied to analyze doped milk samples for and gave good recovery. Thus, we believe that the truncated aptamer/graphene oxide platform is a potential tool for the detection of S. Enteritidis. [ABSTRACT FROM AUTHOR]

A simple microwave-assisted (MWI) wet chemical route to synthesize pure anatase phase titanium dioxide (TiO2) nanoparticles (NPs) is reported here using titanium tetrachloride (TiCl4) as starting material. The as-prepared TiO2 NPs were characterized by electron microscopy, X-ray diffraction, UV/visible absorption spectroscopy, and infrared and Raman spectroscopic techniques. Further modification of the anatase TiO2 NPs was carried out by incorporating plasmonic silver (Ag) NPs and graphene oxide (GO) in order to enhance the visible light absorption. The photocatalytic activities of the anatase TiO2, Ag/TiO2, and Ag/TiO2/GO nanocomposites were evaluated under both ultraviolet (UV) and visible light irradiation using phenol as a model contaminant. The presence of Ag NPs was found to play a significant role to define the photocatalytic activity of the Ag/TiO2/GO nanocomposite. It was found that the Ag performed like a sink under UV excitation and stored photo-generated electrons from TiO2, whereas, under visible light excitation, the Ag acted as a photosensitizer enhancing the photocatalytic activity of the nanocomposite. The detailed mechanism was studied based on photocatalytic activities of Ag/TiO2/GO nanocomposites. Therefore, the as-prepared Ag/TiO2/GO nanocomposite was used as photocatalytic materials under both UV and visible light irradiation toward degradation of organic molecules. [ABSTRACT FROM AUTHOR]

Copper oxide nanoparticles (CuO NPs) are of great interest in nanoscience and nanotechnology because of their broad industrial and commercial applications. Therefore, toxicity of CuO NPs needs to be thoroughly understood. The aim of this study was to investigate the cytotoxicity, genotoxicity, and oxidative stress induced by CuO NPs in human lung epithelial (A549) cells. CuO NPs were synthesized by solvothermal method and the size of NPs measured under transmission electron microscopy (TEM) was found to be around 23 nm. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) and lactate dehydrogenase (LDH) assays showed that CuO NPs (5–15 µg/ml) exert cytotoxicity in A549 cells in a dose-dependent manner. Comet assay suggested concentration-dependent induction of DNA damage due to the exposure to CuO NPs. The comet tail moment was 27% at 15 µg/ml of CuO NPs, whereas it was 5% in control (p < 0.05). The flow cytometry data revealed that CuO NPs induced micronuclei (MN) in A549 cells dose dependently. The frequency of MN was 25/103 cells at 15 µg/ml of CuO NPs, whereas it was 2/103 cells for control. CuO NPs were also found to induce oxidative stress in a concentration-dependent manner, which was indicated by induction of reactive oxygen species (ROS) and lipid peroxidation along with glutathione depletion. Moreover, MN induction and DNA damage were significantly correlated with ROS (R2 = 0.937 for ROS vs. olive tail moment, and R2 = 0.944 for ROS vs. MN). Taken together, this study suggested that CuO NPs induce genotoxicity in A549 cells, which is likely to be mediated through ROS generation and oxidative stress. [ABSTRACT FROM AUTHOR]