Biomimetic poly(glycerol sebacate) (PGS) membranes for cardiac patch application

In this study biomimetic poly(glycerol sebacate) PGS matrix was developed for cardiac patch application. The rationale was that such matrices would provide conducive environment for the seeded cells at the interphase with PGS. From the microstructural standpoint, PGS was fabricated into dense films and porous PGS scaffolds. From the biological aspect, biomimetic PGS membranes were developed via covalently binding peptides Tyr-Ile-Gly-Ser-Arg (YIGSR) and Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP), corresponding to the epitope sequences of laminin and fibronectin, respectively onto the surface. To improve and enhance homogenous binding of peptides onto the PGS surface, chemical modification of its surface was carried out. A sequential regime of alkaline hydrolysis with 0.01 M NaOH for 5 min and acidification with 0.01 M HCl for 25 s was optimal. More COOH chemical group was exposed without causing deleterious effect on the bulk properties of the polymer as revealed by the physicochemical analysis carried out. HPLC analysis, chemical imaging and ToF-SIMS were able to establish the successful homogenous functionalization of PGS membranes with the peptides. Finally, the developed biomimetic membranes supported the adhesion and growth of rat and human cardiac progenitor cells.     

Investigation of the composition of historical and modern Italian papers by energy dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD), and scanning electron microscopy energy dispersive spectrometry (SEM-EDS)

In this work, a study concerning the composition of Italian papers from the seventeenth to the twentieth centuries was carried out using energy dispersive X-ray fluorescence spectrometry (EDXRF), X-ray diffraction (XRD), and scanning electron microscopy coupled to energy dispersive spectrometry (SEM-EDS). The analyzed samples consisted of papers employed for drawing, writing, printing, and absorbance. Observations carried out by SEM magnified the typical paper morphology. EDXRF in combination with XRD and SEM-EDS allowed the determination of calcite, gypsum, kaolin, talc, magnesite, and dolomite, used as fillers in the production of the papers studied herein. The inks present in the handwritten and printed papers, investigated by SEM-EDS and μ-EDXRF, were synthetic, Fe based, and iron gall inks.     

Rapid Quantification of Soyasaponins I and βg in Italian Lentils by High-Performance Liquid Chromatography (HPLC)–Tandem Mass Spectrometry (MS/MS)

In this work, an innovative and fast analytical method for the quantification of soyasaponins I and βg in lentils has been developed. Samples were extracted using 70 % aqueous ethanol at room temperature and then injected into a high-performance liquid chromatography–tandem mass spectrometry system. The correlation coefficients of calibration curves of the analyzed compounds were ≥0.9997. The recoveries obtained by spiking the lentil samples with a standard mixture of soyasaponins I and βg at 50 and 100 mg l^?1 were in the range of 96–101 and 98–103 %, respectively. The validated method was applied to the analysis of 30 lentil samples from central Italy. Soyasaponins I and βg were present in these lentils in concentrations that ranged from 54 to 226 mg kg^?1 and from 436 to 1,272 mg kg^?1, respectively. Our data indicated that lentils cultivated in fields at intermediate altitudes (1,142–1,387 m) showed the highest levels of soyasaponins, a finding confirmed by principal component analysis.     

Stereochemical Outcome of the Biocatalysed Reduction of Activated Tetrasubstituted Olefins by Old Yellow Enzymes 1–3

The ene‐reductase‐mediated reactions of (E)‐ and (Z)‐stereoisomers of tetrasubstituted activated alkenes were performed by means of isolated old yellow enzymes (OYEs) 1–3. The comprehension of the resulting data required a careful analysis of the stereochemical course of this kind of reaction. The investigation of the bioreduction of tetrasubstituted alkenes allowed us to appreciate the contribution of several factors (configuration of the starting alkene, mechanism of hydrogen addition, substrate binding mode) to the overall stereochemistry of the reaction.     

Single electron tunneling in large scale nanojunction arrays with bisferrocene-nanoparticle hybrids

We report on the fabrication and single electron tunneling behaviour of large scale arrays of nanogap electrodes bridged by bisferrocene-gold nanoparticle hybrids (BFc-AuNP). Coulomb staircase was observed in the low temperature current-voltage curves measured on the junctions with asymmetric tunnel barriers. On the other hand, junctions with symmetric tunneling barrier exhibited mere nonlinear current voltage characteristics without discrete staircase. The experimental results agreed well with simulations based on the orthodox theory. The junction resistance showed thermally activated conduction behaviour at higher temperature. The overall voltage and temperature dependent results show that the transport behaviour of the large arrays of single particle devices obtained by a facile optical lithography and chemical etching process corresponds with the behaviour of single particle devices fabricated by other techniques like e-beam lithography and mechanical breaking methods.     

Gas sensing properties of columnar CeO2 nanostructures prepared by chemical vapor deposition

Columnar CeO2 nanostructures are grown on alumina substrates by a template- and catalyst-free Chemical Vapor Deposition (CVD) approach and subsequently tested as resistive gas sensors of CH3COCH3, H2, NO2. The sensor response is stable and reproducible throughout the whole working temperature range (200-500 degrees C) and directly dependent on the analyte gas and the adopted operating conditions. The higher sensitivity with respect to that displayed by continuous CeO2 thin films demonstrates the potential of fabricating nanostructured sensing devices characterized by improved functional performances.     

New biomimetic constructs for improved in vivo circulation of superparamagnetic nanoparticles

Superparamagnetic iron oxide nanoparticles (SPIOs) have been produced and used as a potent and versatile contrast media for magnetic resonance imaging (MRI). Despite a number of efforts to improve their surface chemistry and biocompatibility, the SPIOs half life in blood circulation is very short and they are rapidly taken up by the reticuloendothelial system (RES). In this paper we describe a new method that permits to avoid the rapid clearance of SPIOs. Nanoparticles are made biocompatible by encapsulation into autologous red blood cells. These biomimetic constructs preserve the main properties of the cells that escape RES clearance as well as the properties of the nanoparticles that perform even better than in blood suspension with reduced T2*. These SPIO-loaded RBCs are promising intravascular imaging contrast agents and could also be addressed to selected body compartments by an external magnetic field.     

Chemical composition, in vitro anti-yeast activity and fruit juice preservation potential of lemon grass oil

The anti-yeast activity of lemon grass oil was evaluated against several food spoiling yeasts (Saccharomyces cerevisiae, Zygosaccharomyces bailii, Aureobasidium pullulans, Candida diversa, Pichia fermentans, Pichia kluyveri, Pichia anomala and Hansenula polymorpha) through disc diffusion and microbroth dilution method. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) varied from 0.28 to 1.3 mg/ml and 0.56 to 4.5 mg/ml, respectively, where highest MIC (2.25 mg/ml) was shown by A. pullulans and lowest MIC (0.28 mg/ml) was shown by C. diversa and P. anomala. Kill time assay was conducted for selected three yeast strains where S. cerevisiae showed highest reduction (3 log cfu) in viability within 24 h exposure of lemon grass oil at MFC level. Further, the anti-yeast efficacy of lemon grass oil alone and in combination with thermal treatment was evaluated in real food system i.e. mixed fruit juices. Chemical composition analysis of lemon grass oil by gas chromatography–mass spectrometry (GC–MS) revealed that the dominant compounds were geranial (40.5%), neral (30.7%), geranyl acetate (5.1%), caryophyllene (2.5%). Present results established the superior performance of integrated (thermal–lemon grass oil) treatment over the individual exposure (lemon grass oil or thermal treatment alone) for fruit juice preservation.