The cooperative assembly of biopolymers and small molecules can yield functional materials with precisely tunable properties. Here, the fabrication, characterization, and use of multicomponent hybrid gels as selective gas sensors are reported. The gels are composed of liquid crystal droplets self-assembled in the presence of ionic liquids, which further coassemble with biopolymers to form stable matrices. Each individual component can be varied and acts cooperatively to tune gels' structure and function. The unique molecular environment in hybrid gels is explored for supramolecular recognition of volatile compounds. Gels with distinct compositions are used as optical and electrical gas sensors, yielding a combinatorial response conceptually mimicking olfactory biological systems, and tested to distinguish volatile organic compounds and to quantify ethanol in automotive fuel. The gel response is rapid, reversible, and reproducible. These robust, versatile, modular, pliant electro-optical soft materials possess new possibilities in sensing triggered by chemical and physical stimuli.

Arsenic is a widely distributed environmental toxin whose presence in drinking water poses a threat to >140 million people worldwide. The respiratory enzyme arsenite oxidase from various bacteria catalyses the oxidation of arsenite to arsenate and is being developed as a biosensor for arsenite. The arsenite oxidase from Rhizobium sp. str. NT-26 (a member of the Alphaproteobacteria) is a heterotetramer consisting of a large catalytic subunit (AioA), which contains a molybdenum centre and a 3Fe-4S cluster, and a small subunit (AioB) containing a Rieske 2Fe-2S cluster. Stopped-flow spectroscopy and isothermal titration calorimetry (ITC) have been used to better understand electron transfer through the redox-active centres of the enzyme, which is essential for biosensor development. Results show that oxidation of arsenite at the active site is extremely fast with a rate of >4000s−1 and reduction of the electron acceptor is rate-limiting. An AioB-F108A mutation results in increased activity with the artificial electron acceptor DCPIP and decreased activity with cytochrome c, which in the latter as demonstrated by ITC is not due to an effect on the protein-protein interaction but instead to an effect on electron transfer. These results provide further support that the AioB F108 is important in electron transfer between the Rieske subunit and cytochrome c and its absence in the arsenite oxidases from the Betaproteobacteria may explain the inability of these enzymes to use this electron acceptor.

The cooperative assembly of biopolymers and small molecules can yield functional materials with precisely tunable properties. Here, the fabrication, characterization, and use of multicomponent hybrid gels as selective gas sensors are reported. The gels are composed of liquid crystal droplets self-assembled in the presence of ionic liquids, which further coassemble with biopolymers to form stable matrices. Each individual component can be varied and acts cooperatively to tune gels' structure and function. The unique molecular environment in hybrid gels is explored for supramolecular recognition of volatile compounds. Gels with distinct compositions are used as optical and electrical gas sensors, yielding a combinatorial response conceptually mimicking olfactory biological systems, and tested to distinguish volatile organic compounds and to quantify ethanol in automotive fuel. The gel response is rapid, reversible, and reproducible. These robust, versatile, modular, pliant electro-optical soft materials possess new possibilities in sensing triggered by chemical and physical stimuli.

The xanthine oxidase (XO) family comprises molybdenum-dependent enzymes that usually form homodimers (or dimers of heterodimers/trimers) organized in three domains that harbor two [2Fe-2S] clusters, one FAD, and a Mo cofactor. In this work, we crystallized an unusual member of the family, the periplasmic aldehyde oxidoreductase PaoABC from Escherichia coli. This is the first example of an E. coli protein containing a molybdopterin-cytosine-dinucleotide cofactor and is the only heterotrimer of the XO family so far structurally characterized. The crystal structure revealed the presence of an unexpected [4Fe-4S] cluster, anchored to an additional 40 residues subdomain. According to phylogenetic analysis, proteins containing this cluster are widely spread in many bacteria phyla, putatively through repeated gene transfer events. The active site of PaoABC is highly exposed to the surface with no aromatic residues and an arginine (PaoC-R440) making a direct interaction with PaoC-E692, which acts as a base catalyst. In order to understand the importance of R440, kinetic assays were carried out, and the crystal structure of the PaoC-R440H variant was also determined.

The main objective of TransFlexTeg is to develop an innovative large area distributed sensor network integrating transparent thin film thermoelectric devices and sensors for multifunctional smart windows and flexible high impact volume applications. Different breakthrough concepts will be developed: 1) large area high performance transparent thermoelectric thin films deposited on flexible substrates for thermal energy harvesting; 2) low cost high throughput thin film thermal sensors for thermal mapping and gesture sensing; 3) flexible smart windows and walls with energy harvesting, environmental sensing and wireless communication functionalities. This technology aims to demonstrate the functionalities of a smart window able to measure air quality and environmental parameters such as temperature, sun radiation and humidity. The data is automatically collected and can be utilized for controlling heating, cooling and ventilation systems of indoors. Active radio interface enables long range communication and long term data collection with WiFi or a similar base station. The proposed concept of smart windows replaces several conventional sensors with a distributed sensor network that is integrated invisibly into windows. In addition to the power generated from the thermal energy harvesting, the thermoelectric elements (TE) are also used as temperature sensors that, while being distributed over large area, enable thermal mapping of the area instead of just one or a few values measured from particular points. This smart window can be produced on glass. The active layer itself can be flexible glass layer or polymer sheet, which will significantly broaden the field of applications and improve business opportunities. Both can be manufactured in batch, or in Roll to Roll Atomic Layer Deposition (R2R ALD) process. High environmental impact is expected with savings of more than 25% of the electrical usage of residential homes and office buildings.

Here we describe the establishment of a new canine mammary tumour (CMT) cell line, FR37-CMT that does not show dependence on female hormonal signaling to induce tumour xenografts in NOD-SCID mice. FR37-CMT cell line has a stellate or fusiform shape, displays the ability to reorganize the collagen matrix, expresses vimentin, CD44 and shows the loss of E-cadherin which is considered a fundamental event in epithelial to mesenchymal transition (EMT). The up-regulation of ZEB1, the detection of phosphorylated ERK1/2 and the downregulation of DICER1 and miR-200c are also in accordance with the mesenchymal characteristics of FR37-CMT cell line. FR37-CMT shows a higher resistance to cisplatin (IC50>50 µM) and to doxorubicin (IC50>5.3 µM) compared with other CMT cell lines. These results support the use of FR37-CMT as a new CMT model that may assist the understanding of the molecular mechanisms underlying EMT, CMT drug resistance, fostering the development of novel therapies targeting CMT.

In this work, peptides designed to selectively interact with cellular receptors involved in the regulation of angiogenesis were anchored to oligo-ethylene glycol-capped gold nanoparticles (AuNPs) and used to evaluate the modulation of vascular development using an ex ovo chick chorioallantoic membrane assay. These nanoparticles alter the balance between naturally secreted pro- and antiangiogenic factors, under various biological conditions, without causing toxicity. Exposure of chorioallantoic membranes to AuNP–peptide activators of angiogenesis accelerated the formation of new arterioles when compared to scrambled peptide-coated nanoparticles. On the other hand, antiangiogenic AuNP–peptide conjugates were able to selectively inhibit angiogenesis in vivo. We demonstrated that AuNP vectorization is crucial for enhancing the effect of active peptides. Our data showed for the first time the effective control of activation or inhibition of blood vessel formation in chick embryo via AuNP-based formulations suitable for the selective modulation of angiogenesis, which is of paramount importance in applications where promotion of vascular growth is desirable (eg, wound healing) or ought to be contravened, as in cancer development.

Aldehyde oxidase (AOX1) is an enzyme with broad substrate specificity, catalyzing the oxidation of a wide range of endogenous and exogenous aldehydes as well as N-heterocyclic aromatic compounds. In humans, the enzyme’s role in phase I drug metabolism has been established and its importance is now emerging. However, the true physiologic function of AOX1 in mammals is still unknown. Further, numerous single-nucleotide polymorphisms (SNPs) have been identified in human AOX1. SNPs are a major source of interindividual variability in the human population, and SNP-based amino acid exchanges in AOX1 reportedly modulate the catalytic function of the enzyme in either a positive or negative fashion. For the reliable analysis of the effect of amino acid exchanges in human proteins, the existence of reproducible expression systems for the production of active protein in ample amounts for kinetic, spectroscopic, and crystallographic studies is required. In our study we report an optimized expression system for hAOX1 in Escherichia coli using a codon-optimized construct. The codon-optimization resulted in an up to 15-fold increase of protein production and a simplified purification procedure. The optimized expression system was used to study three SNPs that result in amino acid changes C44W, G1269R, and S1271L. In addition, the crystal structure of the S1271L SNP was solved. We demonstrate that the recombinant enzyme can be used for future studies to exploit the role of AOX in drug metabolism, and for the identification and synthesis of new drugs targeting AOX when combined with crystallographic and modeling studies.

In this work, peptides designed to selectively interact with cellular receptors involved in the regulation of angiogenesis were anchored to oligo-ethylene glycol-capped gold nanoparticles (AuNPs) and used to evaluate the modulation of vascular development using an ex ovo chick chorioallantoic membrane assay. These nanoparticles alter the balance between naturally secreted pro- and antiangiogenic factors, under various biological conditions, without causing toxicity. Exposure of chorioallantoic membranes to AuNP-peptide activators of angiogenesis accelerated the formation of new arterioles when compared to scrambled peptide-coated nanoparticles. On the other hand, antiangiogenic AuNP-peptide conjugates were able to selectively inhibit angiogenesis in vivo. We demonstrated that AuNP vectorization is crucial for enhancing the effect of active peptides. Our data showed for the first time the effective control of activation or inhibition of blood vessel formation in chick embryo via AuNP-based formulations suitable for the selective modulation of angiogenesis, which is of paramount importance in applications where promotion of vascular growth is desirable (eg, wound healing) or ought to be contravened, as in cancer development.

The identification of MUC1 tumor-associated Tn antigen (alpha GalpNAc1-O-Ser/Thr) has boosted the development of anticancer vaccines. Combining microarrays and saturation transfer difference NMR, we have characterized the fine-epitope mapping of a MUC1 chemical library (naked and Tn-glycosylated) toward two families of cancer-related monoclonal antibodies (anti-MUC1 and anti-Tn mAbs). Anti-MUC1 mAbs clone VU-3C6 and VU-11E2 recognize naked MUC1-derived peptides and bind GalNAc in a peptide-sequence-dependent manner. In contrast, anti-Tn mAbs clone 8D4 and 14D6 mostly recognize the GalNAc and do not bind naked MUC1-derived peptides. These anti-Tn mAbs show a clear preference for glycopeptides containing the Tn-Ser antigen rather than the Tn-Thr analogue, stressing the role of the underlying amino acid (serine or threonine) in the binding process. The reported strategy can be employed, in general, to unveil the key minimal structural features that modulate antigen-antibody recognition, with particular relevance for the development of Tn-MUC1-based anticancer vaccines.

The therapeutic promise of small interfering RNAs (siRNAs) for specific gene silencing is dependent on the successful delivery of functional siRNAs to the cytoplasm. Their conjugation to an established delivery platform, such as gold nanoparticles, offers tremendous potential for treating diseases and advancing our understanding of cellular processes. Their success or failure is dependent on both the uptake of the nanoparticles into the cells and subsequent intracellular release of the functional siRNA. In this study, utilizing gold nanoparticle siRNA-mediated delivery against C-MYC, we aimed to determine if we could achieve knockdown in a cancer cell line with low levels of intracellular glutathione, and determine the influence, if any, of polyethylene glycol (PEG) ligand density on knockdown, with a view to determining the optimal nanoparticle design to achieve C-MYC knockdown. We demonstrate that, regardless of the PEG density, knockdown in cells with relatively low glutathione levels can be achieved, as well as the possible effect of steric hindrance of PEG on the availability of the siRNA for cleavage in the intracellular environment. Gold nanoparticle uptake was demonstrated via transmission electron microscopy and mass spectroscopy, while knockdown was determined at the protein and physiological levels (cells in S-phase) by in-cell westerns and BrdU incorporation, respectively.

Nanotechnology based diagnostics has provided improved tools for pathogen detection and sensitive and specific characterization of antibiotic resistance signatures. Tuberculosis (TB) is caused by members of the Mycobacterium tuberculosis Complex (MTBC) and, according to the World Health Organization, is one of the most serious infectious diseases in the world. Recent advances in molecular diagnostics of TB have improved both the detection time and sensitivity but they still require specialized technical personnel and cumbersome laboratory equipment. Diagnostics at point-of-need is crucial to TB control as it may provide rapid identification of pathogen together with the resistance profile of TB strains, originated from single nucleotide polymorphisms (SNPs) in different loci , allowing for a more accurate indication of the adequate therapy.Gold nanoparticles have been widely used in molecular diagnostics platforms. Here, we describe the use of gold nanoprobes (oligonucleotide functionalized gold nanoparticles) to be used in a non-crosslinking colorimetric method for the direct detection of specific DNA targets. Due to the remarkable optical properties of gold nanoparticles, this detection system provides colorimetric detection of the pathogen together with the potential of identification of several single nucleotide polymorphisms (SNPs) involved in TB resistance to antibiotics. For point-of-need use, we adapted this strategy to a low-cost mobile scheme using a paper based revelation platform and where the spectral signature is transposed to RGB data via a smartphone device. This way, identification of pathogen and characterization of resistance signatures is achieved at point-of-need.

RNAi has always captivated scientists due to its tremendous power to modulate the phenotype of living organisms. This natural and powerful biological mechanism can now be harnessed to downregulate specific gene expression in diseased cells, opening up endless opportunities. Since most of the conventional siRNA delivery methods are limited by a narrow therapeutic index and significant side and off-target effects, we are now in the dawn of a new age in gene therapy driven by nanotechnology vehicles for RNAi therapeutics. Here, we outlook the {"}do's and dont's{"} of the inorganic RNAi nanomaterials developed in the last 15 years and the different strategies employed are compared and scrutinized, offering important suggestions for the next 15. (C) 2015 Elsevier Ltd. All rights reserved.