The incorporation of europium polyoxometalates into silica nanoparticles can lead to a biocompatible nanomaterial with luminescent properties suitable for applications in biosensors, biological probes, and imaging. Keggin-type europium polyoxometalates Eu(PW11)x (x = 1 and 2) with different europium coordination environments were prepared by using simple methodologies and no expensive reactants. These luminescent compounds were then encapsulated into silica nanoparticles for the first time through the water-in-oil microemulsion methodology with a nonionic surfactant. The europium polyoxometalates and the nanoparticles were characterized by using several techniques [FTIR, FT-Raman, 31P magic angle spinning (MAS) NMR, and TEM/energy-dispersive X-ray spectroscopy (TEM-EDS), AFM, dynamic light scattering (DLS), and inductively coupled plasma MS (ICP-MS) analysis]. The stability of the material and the integrity of the europium compounds incorporated were also examined. Furthermore, the photoluminescence properties of the Eu(PW11)x@SiO2 nanomaterials were evaluated and compared with those of the free europium polyoxometalates. The silica surface of the most stable nanoparticles was successfully functionalized with appropriate organosilanes to enable the covalent binding of oligonucleotides.

The subject of ionicity has been extensively discussed in the last decade, due to the importance of understanding the thermodynamic and thermophysical behaviour of ionic liquids. In our previous work, we established that ionic liquids' ionicity could be improved by the dissolution of simple inorganic salts in their milieu. In this work, a comparison between the thermophysical properties of two binary systems of ionic liquid + inorganic salt is presented. The effect of the ammonium thiocyanate salt on the ionicity of two similar ionic liquids, 1-ethyl-3-methylimidazolium ethylsulfonate and ethylsulfate, is investigated in terms of the related thermophysical properties, such as density, viscosity and ionic conductivity in the temperature range 298.15-323.15 K. In addition, spectroscopic (NMR and Raman) and molecular dynamic studies were conducted in order to better understand the interactions that occur at a molecular level. The obtained results reveal that although the two anions of the ionic liquid exhibit similar chemical structures, the presence of one additional oxygen in the ethylsulfate anion has a major impact on the thermophysical properties of the studied systems.

Traditional methods of drug delivery present several drawbacks, mainly due to off-target effects that may originate severe side and toxic effect to healthy tissues. Parallel to the development of novel more effective drugs, particular effort has been dedicated to develop and optimize drug delivery vehicles capable of specifically targeting the required tissue/organ and to deliver the cargo only where and when it is needed. New drug delivery systems based on nanoscale devices showing new and improved pharmacokinetic and pharmacodynamics properties like enhanced bioavailability, high drug loading or systemic stability have surged in the past decade as promising solutions to the required therapeutic efficacy. Amongst these nanoscale vectors, nanoparticles for drug delivery, such as polymeric, lipidbased, ceramic or metallic nanoparticles, have been at the forefront of pharmaceutical development. The interest in nanomedicine for treatment and diagnosis is clearly reflected on the increasing number of publications and issued patents every year. Here, we provide a broad overview of novel nanoparticle based drug delivery systems, ranging from polymeric systems to metal nanoparticles, while simultaneously listing the most relevant related patents.

Nanotechnology has emerged as a {"}disruptive technology{"} that may provide researchers with new and innovative ways to diagnose, treat and monitor cancer. In fact, nanomedicine approaches have delivered several strategies, such as new imaging agents, real-time assessments of therapeutic and surgical efficacy, multifunctional, targeted devices capable of bypassing biological barriers to target and silence specific pathways in tumours. Of particular interest, has been the increased capability to deliver multiple therapeutic agents directly to bulk cancer cells and cancer stem cells that play a critical role in cancer growth and metastasis. These multifunctional targeted nanoconjugates are also capable of avoiding cancer resistance and monitor predictive molecular changes that open the path for preventive action against pre-cancerous cells, minimizing costs and incidence of relapses. A myriad of nanoconjugates with effective silencing and site-targeting moieties can be developed by incorporating a diverse selection of targeting, diagnostic, and therapeutic components. A discussion of the integrative effort of nanotechnology systems with recent developments of biomolecular interactions in cancer progression is clearly required. Here, we will update the state of the art related to the development and applications of nanoscale platforms and novel biomolecular players in cancer diagnosis, imaging and treatment.

The preferential binding of anions and cations in aqueous solutions of the ionic liquids (ILs) 1-butyl- 3-methylimidazolium ([C₄mim]⁺) and 1-ethyl-3-methylimidazolium ([C₂mim]⁺) chloride and dicyanamide (dca^-) with the small alpha-helical protein Im7 was investigated using a combination of differential scanning calorimetry, NMR spectroscopy and molecular dynamics (MD) simulations. Our results show that direct ion interactions are crucial to understand the effects of ILs on the stability of proteins and that an anion effect is dominant. We show that the binding of weakly hydrated anions to positively charged or polar residues leads to the partial dehydration of the backbone groups, and is critical to control stability, explaining why dca^- is more denaturing than Cl^-. Direct cation–protein interactions also mediate stability; cation size and hydrophobicity are relevant to account for destabilisation as shown by the effect of [C₄mim]⁺ compared to [C₂mim]⁺. The specificity in the interaction of IL ions with protein residues established by weak favourable interactions is confirmed by NMR chemical shift perturbation, amide hydrogen exchange data and MD simulations. Differences in specificity are due to the balance of interaction established between ion pairs and ion-solvent that determine the type of residues affected. When the interaction of both cation and anion with the protein is strong the net result is similar to a non-specific interaction, leading ultimately to unfolding. Since the nature of the ions is a determinant of the level of interaction with the protein towards denaturation or stabilisation, ILs offer a unique possibility to modulate protein stabilisation or even folding events.

We present relaxivities measurements for both the longitudinal and transverse relaxations of two types of liposomes loaded with ultra small superparamagnetic iron oxide nanoparticles. The magnetoliposome systems presented are soybean phosphatidylcholine liposomes, with and without cholesterol, in the phospholipid bilayer with different molar ratios lipid:cholesterol. In fact, cholesterol is needed to obtain stable liposomes for intravenous administration. The longitudinal and transverse relaxivities were measured with a NMR spectrometer in a 7T magnetic field. For the studied concentrations, the liposomes show a negligible effect on the longitudinal relaxation time T1 of the medium, but they are very efficient on decreasing the transverse relaxation time T2, the behaviour one expects for a negative CA. We observed a lower transverse relaxivity for the magnetoliposome nanosystem with cholesterol, which strongly decreases with the cholesterol content in the liposome bilayer.

Non-catalytic cellulosomal carbohydrate-binding modules (CBMs) are responsible for increasing the catalytic efficiency of cellulosic enzymes by selectively putting the substrate (a wide range of poly- and oligosaccharides) and enzyme into close contact. In the present work we carried out an atomistic rationalization of the molecular determinants of ligand specificity of a family 11 CBM from thermophilic C. thermocellum (CtCBM11), based on a NMR and molecular modeling approach. We have determined the NMR solution structure of CtCBM11 at 25 and 50 ºC and derived information on the residues of the protein involved in ligand recognition and on the influence of the length of the saccharide chain on binding. We obtained models of the CtCBM11/cellohexaose and CtCBM11/cellotetraose complexes by docking in accordance with the NMR experimental data. Specific ligand/protein CH-π and Van der Waals interactions were found to be determinant for the stability of the complexes and for defining specificity. Using the order parameters derived from backbone dynamics analysis in the presence and absence of ligand and at 25 and 50 ºC, we determined that the protein’s backbone conformational entropy is slightly positive. This data in combination with the negative binding entropy calculated from ITC studies supports a selection mechanism where a rigid protein selects a defined oligosaccharide conformation.

This work assesses the characteristics of magnetoliposomes of soybean phosphatidylcholine (SPC):cholesterol (Chol) loaded with superparamagnetic iron oxide nanoparticles (IONPs) stabilized with tetramethylammonium hydroxide (TMAOH) and their capacity to enhance magnetic resonance imaging (MRI) contrast. Magnetoliposomes of SPC were used for comparative studies. IONPs and magnetoliposomes were characterized using transmission electron microscopy, dynamic light scattering, SQUID magnetometry, FTIR and MRI. The saturation magnetization at 10K was  0.06 Am(2)/kg for SPC:Chol magnetoliposomes with 7 g iron oxide/mol of lipid and  0.05 Am(2)/kg for SPC magnetoliposomes with 21 g iron oxide/mol of lipid. As these values are associated with the number of incorporated magnetic IONPs, the saturation magnetization is 1.2 times higher for magnetoliposomes of SPC:Chol as compared with magnetoliposomes of SPC alone. The behavior of temperature dependence in both cases is typical of superparamagnetic particles. FTIR spectra evidence the increase of magnetoliposome membrane ordering with the presence of Chol. Principal component analysis (PCA) applied to FTIR spectra evidenced a clear distinction between scores for SPC:Chol, and SPC magnetoliposomes and for SPC empty liposomes. PCA applied to FTIR data differentiate magnetoliposomes from empty liposomes. MR images of aqueous phantoms obtained with and without magnetoliposomes, clearly evidence their effect on T2 image weighting.

A novel porous polymer-ionic liquid composite with poly(2-hydroxyethyl methacrylate) (PHEMA) and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF6) has been synthesized by gamma-irradiation without heat or chemical initiators. The products can be reversibly converted into organogels. The composites are potential candidates for electrochemical applications. The use of gamma-radiation can be a simple and versatile alternative way to obtain these materials. (C) 2012 Elsevier B.V. All rights reserved.

A novel porous polymer-ionic liquid composite with poly(2-hydroxyethyl methacrylate) (PHEMA) and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF6) has been synthesized by γ-irradiation without heat or chemical initiators. The products can be reversibly converted into organogels. The composites are potential candidates for electrochemical applications. The use of γ-radiation can be a simple and versatile alternative way to obtain these materials.

Water-based cellulose cholesteric liquid crystalline phases at rest can undergo structural changes induced by shear flow. This reflects on the deuterium spectra recorded when the system is investigated by rheo-nuclear magnetic resonance (rheo-NMR) techniques. In this work, the model system hydroxypropylcellulose (HPC)+water is revisited using rheo-NMR to clarify unsettled points regarding its behavior under shear and in relaxation. The NMR spectra allow the identification of five different stable ordering states, within shear and relaxation, which are well integrated in a mesoscopic picture of the system's structural evolution under shear and relaxation. This picture emerging from the large body of studies available for this system by other experimental techniques, accounts well for the NMR data and is in good agreement with the three distinct regions of steady shear flow recognized for some lyotropic LC polymers. Shear rates in between 0.1 and 1.0 s(-1) where investigated using a Taylor-Couette flow and deuterated water was used as solvent for the deuterium NMR (DNMR) analysis.

The present work focuses on a qualitative analysis of localised I-V characteristics based on the nanostructure morphology of highly dense arrays of p-type NiO nano-pillars (NiO-NPs). Vertically aligned NiO-NPs have been grown on different substrates by using a glancing angle deposition (GLAD) technique. The preferred orientation of as grown NiO-NPs was controlled by the deposition pressure. The NiO-NPs displayed a polar surface with a microscopic dipole moment along the (111) plane (Tasker's type III). Consequently, the crystal plane dependent surface electron accumulation layer and the lattice disorder at the grain boundary interface showed a non-uniform current distribution throughout the sample surface, demonstrated by a conducting AFM technique (c-AFM). The variation in I-V for different points in a single current distribution grain (CD-grain) has been attributed to the variation of Schottky barrier height (SBH) at the metal-semiconductor (M-S) interface. Furthermore, we observed that the strain produced during the NiO-NPs growth can modulate the SBH. Inbound strain acts as an external field to influence the local electric field at the M-S interface causing a variation in SBH with the NPs orientation. This paper shows that vertical arrays of NiO-NPs are potential candidates for nanoscale devices because they have a great impact on the local current transport mechanism due to its nanostructure morphology.

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