Surface modification of basalt fibres with ZnO nanorods and its effect on thermal and mechanical properties of pla-based composites

The composites based on basalt fibres and poly(lactic acid) (PLA) show promising applications in biomedical and automotive fields, but their mechanical performance is still largely hindered by poor interfacial properties. Zinc oxide nanorods have been successfully used to tune the PLA/basalt fibre interface by growing them on commercially available basalt fabrics. The hierarchical fibres significantly enhanced the mechanical properties of PLA-based composites, especially their flexural strength and stiffness. These values are 26% and 22% higher than those of unmodified basalt/PLA composites, and 24% and 34% higher than those of glass/PLA composites used as a baseline. The increase in tensile and flexural properties hinges on the mechanical interlocking action promoted by ZnO nanorods and on the creation of a compact transcrystallinity structure. A degradation of PLA matrix was detected but it was positively counteracted by the better interfacial stress transfer. This study offers a novel approach for modifying the fibre–matrix interface of biocomposites intended for high-performance applications

Hyaluronic acid reduces bacterial fouling and promotes fibroblasts’ adhesion onto chitosan 2D-wound dressings

Wound healing is a dynamic process that can be seriously delayed by many factors including infectious complications. The development of dressings with intrinsic wound healing activity and/or releasing bioactive compounds may help with addressing such an issue. In this study, hyaluronic acid (HA) at different percentages (1–35%) was used to modify chitosan (CS) biological and physico-chemical properties in order to obtain 2D-matrices able to promote healing and protect from infection. HA incorporation in the CS matrix decreased film transparency and homogeneity, but improved film water uptake and surface wettability. The water vapor transmission rate (WVTR) increased up to a 5% HA content, where it reached the highest value (672 g/m2 day), and decreased for higher HA contents. At all of the tested HA concentrations, HA affected mechanical properties providing matrices more flexible than pure CS with benefit for wound care. Pure CS films permitted S. epidermidis adhesion and biofilm formation. That was not true for CS/HA matrices, where HA at concentrations equal to or greater than 5% was able to avoid S. epidermidis adhesion. Fibroblasts adhesion also took benefit from the HA presence in the film, especially at 5% content, where the best adhesion and proliferation was found

Liquid Structure of a Water-in-Salt Electrolyte with a Remarkably Asymmetric Anion

Water-in-salt systems, i.e., super-concentrated aqueous electrolytes, such as lithium bis(trifluoromethanesulfonyl)imide (21 mol/kgwater), have been recently discovered to exhibit unexpectedly large electrochemical windows and high lithium transference numbers, thus paving the way to safe and sustainable charge storage devices. The peculiar transport features in these electrolytes are influenced by their intrinsically nanoseparated morphology, stemming from the anion hydrophobic nature and manifesting as nanosegregation between anions and water domains. The underlying mechanism behind this structure-dynamics correlation is, however, still a matter of strong debate. Here, we enhance the apolar nature of the anions, exploring the properties of the aqueous electrolytes of lithium salts with a strongly asymmetric anion, namely, (trifluoromethylsulfonyl)(nonafluorobutylsulfonyl) imide. Using a synergy of experimental and computational tools, we detect a remarkable level of structural heterogeneity at a mesoscopic level between anion-rich and water-rich domains. Such a ubiquitous sponge-like, bicontinuous morphology develops across the whole concentration range, evolving from large fluorinated globules at high dilution to a percolating fluorous matrix intercalated by water nanowires at super-concentrated regimes. Even at extremely concentrated conditions, a large population of fully hydrated lithium ions, with no anion coordination, is detected. One can then derive that the concomitant coexistence of (i) a mesoscopically segregated structure and (ii) fully hydrated lithium clusters disentangled from anion coordination enables the peculiar lithium diffusion features that characterize water-in-salt systems

Role of MicroRNA Profile Modifications in Hepatitis C Virus-Related Mixed Cryoglobulinemia

Hepatitis C virus infection is closely related to lymphoproliferative disorders (LPDs), including mixed cryoglobulinemia (MC) and some lymphomas. Modification of the expression of specific microRNAs (miRNAs) has been associated with different autoimmune diseases and/or LPDs. No data exist about the modifications in miRNA expression in HCV-associated LPDs. The aim of this study was to analyze the expression levels of a panel of miRNAs previously associated with autoimmune/LPDs in a large population of HCV patients with and without MC or non-Hodgkin’s lymphoma (NHL), to identify potential markers of evolution of HCV infection. PBMC expression of miR-Let-7d, miR-16, miR-21, miR-26b, miR-146a and miR-155 was evaluated by real-time PCR in 167 HCV patients (75 with MC [MC-HCV], 11 with HCV-associated NHL [NHL-HCV], 81 without LPD [HCV]) and in 35 healthy subjects (HS). A significant increase in miR-21 (p<0.001), miR-16 (p<0.01) and miR-155 (p<0.01) expression was detected in PBMCs from only NHL patients whereas a significant decrease in miR-26b was detected in both MC and NHL subjects (p<0.01) when compared to HS and HCV groups. A restoration of miR-26b levels was observed in the post-treatment PBMCs of 35 HCV-MC patients experiencing complete virological and clinical response following antiviral therapy. This study, for the first time, shows that specific microRNAs in PBMC from HCV patients who developed MC and/or NHL are modulated differently. The specific, reversible downregulation of miR-26b strongly suggests the key role it plays in the pathogenesis of HCV-related LPDs and its usefulness as a biomarker of the evolution of HCV infection to these disorders

Hydrophobic Eutectic Solvent with Antioxidant Properties: Application for the Dispersive Liquid-Liquid Microextraction of Fat-Soluble Micronutrients from Fruit Juices

Despite the great interest devoted to eutectic solvents with significant negative deviations from ideality (namely, deep eutectic solvents), many hydrophobic liquid mixtures are ideal or quasi-ideal systems. In this regard, we propose the introduction of a hydrophobic eutectic solvent based on l-menthol and butylated hydroxytoluene, blended in a molar ratio of 3:1. The physicochemical characterization by means of differential scanning calorimetry and infrared spectroscopy has identified that it is an ideal eutectic solvent. Compared to other hydrophobic mixtures, this one represents an advanced solvent system due to its intrinsic antioxidant activity, which makes it an ideal green choice for the extraction and preservation of easily oxidizable lipophilic compounds. In order to evaluate its efficiency, it was applied for the first time as an extractant for the dispersive liquid-liquid microextraction of carotenoids and fat-soluble vitamins from fruit juices, carried out at 298 K. All extracts were analyzed by high-performance liquid chromatography-tandem mass spectrometry. The developed method was then validated, providing precise (4-8%) and accurate (4-6%) results on a commercial fruit juice containing declared values of β-carotene and α-tocopherol acetate. Recoveries were ≥70%, while the detection limits were 0.05 μg L-1 for β-carotene and 0.28 μg L-1 for α-tocopherol acetate. Here, we also propose an original approach to properly determine the antioxidant activity of eutectic mixtures since the available commercial kits cannot be applied to such systems without altering their nature. Last but not least, a circular process of reuse of this ideal eutectic solvent has been developed using a low-cost activated carbon material obtained from coconut shells

Analisi FT-IR a modulazione di temperatura di trattamenti termici sul PLLA amorfo

Esperimenti di physical aging, thermal rejuvenation e di recupero del rilassamento al di sopra della Tg sono stati seguiti mediante l’analisi dell’evoluzione dello spettro FTIR in funzione di un programma costituito dalla sovrapposizione di un riscaldamento lineare ed una modulazione di temperatura. Ciò ha permesso di dividere la variazione della concentrazione relativa dei conformeri a bassa (gt) ed alta energia (gg) del PLLA amorfo, ottenuto per quenching dallo stato fuso, nelle componenti reversibile e non-reversibile. La tecnica ha messo in luce che i campioni di polimero aged e non-aged non raggiungono lo stato di equilibrio liquido a T>Tg, ma si evolvono irreversibilmente anche ad alte temperature, in prossimità della cold-crystallization. Campioni che hanno subito invece thermal rejuvenation a T>Tg non presentano tale fenomeno

Study on isotactic polypropylene melt-crystallization by temperature modulated FTIR

La cristallizzazione da fuso del polipropilene isotattico è stata studiata in condizioni dinamiche mediante un’implementazione dell’FTIR a temperatura variabile. Per questo scopo, gli spettri sono acquisiti sequenzialmente durante un programma di temperatura che prevede una rampa di raffreddamento lineare con sovrimposta una funzione periodica (Temperature Modulated FTIR, TMFTIR). L’elaborazione delle intensità delle bande vibrazionali, associate alle strutture elicoidali 31 della catena dell’i-PP, ha come risultato la separazione dei fenomeni reversibili da quelli non reversibili in funzione della temperatura. È stato evidenziato nelle fasi finali della melt-crystallization un fenomeno reversibile, la cui intensità dipende dalle bande vibrazionali analizzate, che in parte può essere attribuito alla cristallizzazione reversibile dell’i-PP

Application of temperature modulation to FTIR spectroscopy: an analysis of equilibrium and non-equilibrium conformational transitions of poly(ethylene terephthalate) in glassy and liquid states

In this paper, the application of a temperature modulation to the temperature-resolved FTIR analysis is reported. The advantage offered by the spectroscopic investigation, able to follow the micro-structural and conformational sample modification involved in sample thermal transformation, was merged to that of temperature modulation, related to the possibility to separate the reversing (in-equilibrium within the experimental condition) to the non-reversing (non-equilibrium) processes. The potentiality of the technique (modulated temperature FTIR, MTFTIR) is highlighted through the study of the thermal transitions of amorphous poly(ethylene terephthalate) from 50&nbsp;°C to the cold-crystallization. After the presentation of the theoretical framework and the experimental conditions, a step-by-step description of acquired data elaboration is given. The total variation of a selected band intensity as function of mean temperature as well as its reversing and non-reversing components are obtained. The evolution of the bands at 1340 and 971&nbsp;cm−1, assigned to the trans conformation of the ethylenic unit and to the all-trans conformation of the repeating unit, respectively, are investigated. As expected, the glass transition is observed in the reversing components meanwhile the recovery of the glass relaxation and cold crystallization in non-reversing ones. Particularly interesting resulted the behaviour of the sample in the supercooled liquid state, between the glass transition and the cold-crystallization onset, in which the results show that the ethylenic conformers are in-equilibrium while the all-trans sequences are not. MTFTIR is confirmed to be a technique particularly suitable for the characterization of non-equilibrium conformational states of polymers

Liquid structure of a choline chloride-water natural deep eutectic solvent: A molecular dynamics characterization

The liquid structure of a representative of the first water-in-salt (WiS) Natural Deep Eutectic Solvents (NADES), hereinafter indicated as aquoline, a mixture of choline chloride (ChCl) and water with molar ratio 1:3.33, is explored at ambient conditions. Using Molecular Dynamics (MD) simulation tools, we extract structural information at atomistic level on the nature of inter-correlations between the different moieties. Despite being a very fluid liquid, with much lower viscosity than other common ChCl-based DES, aquoline turns out to be very structured. Computed X-ray and neutron weighted scattering patterns (the latter also on selectively deuterated mixtures) highlight the existence of mesoscopic organization that is rationalised in terms of choline vs. water/chloride structural alternation. The study shows that choline cations are highly coordinating the surrounding environment: strong hydrogen bonding mediated correlations between the hydroxyl group and water or chloride are detected. In addition, the ammonium group drives the formation of a complex solvating environment, with water, chloride and hydroxyl moieties approaching it, between the hindering methyl groups. Strong hydrogen-bonding interactions between water molecules and between water and anions are detected and, while water cannot create a bulk water-like environment around itself, its network with neighbour water or anions develops long chains across the bulk phase. This is a first study that will be extended based on complementary experimental work as a function of water content and temperature/pressure, to explore structural and dynamic properties of this class of materials

Influence of food emulsifiers on cellular function and inflammation, a preliminary study

Emulsifiers are extensively used as food additives and their consumption is increasing in Western countries. However, so far only few studies examined their potential effects on intestinal cellular functions and gut inflammation. The aim of this preliminary analysis was to study the emulsifiers and their concentrations capable of causing cellular damage compared to extra virgin olive oil (EVOO). We tested two commonly used emulsifiers (EMI, EMII) and EVOO on Caco-2 cells, derived from a colon carcinoma and widely used as a model of the intestinal inflammation. The diphenyltetrazolium bromide test MTT and clonogenic assay were used to study the effect of emulsifiers on cell viability. Cell migration was determined by the wound-healing assay. The inflammation was studied by measuring the levels of interleukin 6 (IL-6) and monocyte chemoattractant protein-1/C-C motif chemokine ligand 2 (CCL2), multifunctional cytokines with a major role in the acute-phase response. Furthermore, we analyzed the effect of conditioned media of Caco-2 cells treated with EMs on macrophages activation. In conclusion, our preliminary data provide evidence that EMs increase the proliferation and migration rate of Caco-2 cells. Moreover, Caco-2 cells treated with EMs enhance the IL-6 and CCL2 release and activated macrophages, supporting their role as proinflammatory molecules