Size and time-dependent induction of proinflammatory cytokines expression in brains of mice treated with gold nanoparticles

Gold nanoparticles (GNPs) are among the ideal nano-sized materials for medical applications such as imaging and drug delivery. Considering the significance of recent reports on acute phase induction of inflammatory mediators by GNPs, we studied the effect of GNPs on proinflammatory cytokines gene expression in mouse brain. Group 1 served as control whereas groups 2–4 were given only one intraperitoneal dose of 5, 20 and 50?nm GNPs, respectively and sacrificed after 24?h. The animals in groups 5–7 also received the same treatment but sacrificed after 7?days. Groups 8–10 received two injections of GNPs (5, 20 and 50?nm, respectively), first at the beginning of study and second on day 6, and sacrificed on day 7. Total RNA was extracted from the cerebral tissue and analyzed for the gene expressions of IL-1β, IL-6 and TNF-α. A single injection of 5?nm diameter GNPs significantly increased the mRNA expression of IL-1β and IL-6 in mouse brain on day 7, which was not augmented by the second dose of the same GNPs. Larger size GNPs (20?nm and 50?nm) did not cause any significant change in the expression of proinflammatory cytokines in mouse brain. In conclusion, systemic administration of small sized GNPs (5?nm) induced a proinflammatory cascade in mouse brain indicating a crucial role of GNPs size on immune response. It is important to use the right sized GNPs in order to avoid an acute phase inflammatory response that could be cytotoxic or interfere with the bioavailability of nanomaterials.     

Antiangiogenic properties of Koetjapic acid, a natural triterpene isolated from Sandoricum koetjaoe Merr

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.     

Development of a highly sensitive bacteria detection assay using fluorescent pH-responsive polymeric micelles

The detection and control of bacteria is extremely important in the safety of food products and health systems. The conventional microbiological methods based on culture enrichment techniques and plating procedures are highly sensitive and selective for bacterial detection but are expensive, cumbersome and time-consuming. Here we report the development of a simple and sensitive bioassay to detect Escherichia coli (E. coli) bacteria by using self assembled pH-responsive polymeric micelles that have been bioconjugated to anti-E. coli (capturing agent). Poly(ethylene glycol-b-trimethylsilyl methacrylate), containing silicon moieties that can be cleaved under mildly acidic conditions, was synthesized and self-assembled into micelles, that were loaded with a fluorescent dye (1-methylpyrene). The polymer silicon protecting groups are used as a tool to remotely activate the dye release by means of pH. The high sensitivity of the newly developed bioassay, which is capable of detecting 15 bacteria per milliliter of solution, is due to an amplification effect generated by the optical signal of millions of fluorophores released from a single micelle upon attachment to a bacterium. Fluorescence probing involves the measurements of changes in the emission spectra, through the disappearance of the excimer band, which only occurs when the dye molecules are trapped within the polymeric micelles.     

Machine learning algorithm-based risk prediction model of coronary artery disease

Molecular Biology Reports - In view of high mortality associated with coronary artery disease (CAD), development of an early predicting tool will be beneficial in reducing the burden of the...     

Purification and characterization of adenosine deaminase from camel skeletal muscle

Adenosine deaminase was purified (780-fold) from skeletal muscle of camel (Camelus Dormedarius) to homogeneity level by using DEAE Sephadex chromatography, ammonium sulfate precipitation, gel filtration and ion exchange chromatography. The enzyme appeared to be monomeric with subunit molecular weight of 43kDa and isoelectric point of 4.85. The enzyme showed specificity for adenosine and exhibited Michaelis-Menten Kinetics with kappa(cat) of 1112.41 min(-1) and K(m) of 14.7 microM at pH 7.5. The pH and temperature optima for enzyme activity were 7-7.5 and 25 degrees C, respectively. Free energy (DeltaG*), enthalpy (DeltaH*) and entropy (DeltaS*) of activation for denaturation of adenosine deaminase at 50 degrees C were 88.94, 99.65 kJmol(-1) and 33.16 Jmol(-1), respectively. The purified enzyme had half-lives of 636 and 61 min at 25 and 50 degrees C, respectively. The activation energy for catalysis of camel skeletal muscle adenosine deaminase was 9.13 kJmol(-1). Free energy (DeltaG#), enthalpy (DeltaH#) and entropy (DeltaS#) of activation for hydrolysis of adenosine deaminase at 25 degrees C were 50.35, 6.65 kJmol(-1) and -146.62 Jmol(-1), respectively. Purine riboside inhibited the enzyme competitively with K(i) of 16 microM.     

Chemical synthesis and improved expression of recombinant human granulocyte colony-stimulating factor cDNA

Recently, granulocyte colony-stimulating factor (G-CSF) has been recognized as a useful molecule for the treatment of a wide range of complex ailments, such as cancer, AIDS, H1N1 influenza, cardiac and neurological diseases. The vast therapeutic potential of G-CSF has induced scientists to develop biotechnological approaches for the synthesis of this pharmacologically active agent. We used a synthetic G-CSF cDNA molecule to produce the target protein by a simple cloning protocol. We constructed the synthetic cDNA using a DNA synthesizer with the aim to increase its expression level by specific sequence modifications at the 5' end of the G-CSF-coding region, decreasing the GC content without altering the predicted amino acid sequences. The identity of the resulting protein was confirmed by a highly specific enzyme-linked immunosorbent assay. In conclusion, a synthetic G-CSF cDNA in combination with the recombinant DNA protocol offers a rapid and reliable strategy for synthesizing the target protein. However, commercial utilization of this methodology will require rigorous validation and quality control.