Comparative performance of collagen nanofibers electrospun from different solvents and stabilized by different crosslinkers

Collagen electrospun scaffolds well reproduce the structure of the extracellular matrix (ECM) of natural tissues by coupling high biomimetism of the biological material with the fibrous morphology of the protein. Structural properties of collagen electrospun fibers are still a debated subject and there are conflicting reports in the literature addressing the presence of ultrastructure of collagen in electrospun fibers. In this work collagen type I was successfully electrospun from two different solvents, trifluoroethanol (TFE) and dilute acetic acid (AcOH). Characterization of collagen fibers was performed by means of SEM, ATR-IR, Circular Dichroism and WAXD. We demonstrated that collagen fibers contained a very low amount of triple helix with respect to pristine collagen (18 and 16 % in fibers electrospun from AcOH and TFE, respectively) and that triple helix denaturation occurred during polymer dissolution. Collagen scaffolds were crosslinked by using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), a commonly employed crosslinker for electrospun collagen, and 1,4-butanediol diglycidyl ether (BDDGE), that was tested for the first time in this work as crosslinking agent for collagen in the form of electrospun fibers. We demonstrated that BDDGE successfully crosslinked collagen and preserved at the same time the scaffold fibrous morphology, while scaffolds crosslinked with EDC completely lost their porous structure. Mesenchymal stem cell experiments demonstrated that collagen scaffolds crosslinked with BDDGE are biocompatible and support cell attachment.     

On the characterization of medicated plasters containing NSAIDs according to novel indications of USP and EMA: adhesive property and in vitro skin permeation studies

This work aims to establish if the assays recently introduced by EMA (Guideline on quality of transdermal patches-draft) and USP (Specific tests for transdermal delivery systems) to characterize transdermal patches (TP) are suitable for medicated plasters (MP). Six approved MP differing for type and characteristics of adhesive and backing layer were selected and characterized in terms of adhesive performances by tack, shear adhesion, peel adhesion and release liner removal tests and in vitro skin permeation. As far as the adhesive properties are concerned, the major drawback is related to the measurement of shear adhesion of MP made of an adhesive hydrogel and/or a stretchable backing layer which could be solved by reducing the applied load. Moreover, a concern on the mass balance prescribed by EMA draft for the acceptance of the results of in vitro penetration studies remains. Indeed, the acceptance range is narrow than that reported by Ph. Eur. requirement for uniformity of content. Finally, a novel calculation for evaluating the in vitro efficiency of MP in releasing the loaded drug through the skin was proposed.     

Effects of Nylon 6,6 nanofibrous mats on thermal properties and delamination behavior of high performance CFRP laminates

Nylon 6,6 electrospun nanofibrous membranes interleaved in “high performance” Carbon Fiber Reinforced Polymer (CFRP) laminates have been proposed as a means to provide a high threshold value to delamination on structural sites where composites are more prone to develop such failure. A model, highly crosslinked, thus inherently brittle, epoxy matrix was selected for its high Young's modulus and glass transition temperature exceeding 250°C. The influence of the Nylon 6,6 nanofibers on the curing behavior of the matrix and on the thermal and dynamic mechanical properties of the cured resin was investigated. These properties were related to the features of the epoxy resin and of the resin impregnated nanofibrous mat. Finally, the delamination behavior of the composite laminates interleaved with Nylon interleaves with different thicknesses was studied through Mode I delamination tests on Double Cantilever Beam (DCB) samples. The results show that the initial Mode I fracture toughness was increased up to about 50% by the presence of the thin mat interleaf. POLYM. COMPOS., 36:1303–1313, 2015. © 2014 Society of Plastics Engineers     

Fluorine NMR‐Based Screening on Cell Membrane Extracts

The possibility of measuring the action of inhibitors of specific enzymatic reactions in intact cells, cell lysates or membrane preparations represents a major advance in the lead discovery process. Despite the relevance of assaying in physiological conditions, only a small number of biophysical techniques, often requiring complex set‐up, are applicable to these sample types. Here, we demonstrate the first application of n‐fluorine atoms for biochemical screening (n‐FABS), a homogeneous and versatile assay based on ¹⁹F NMR spectroscopy, to the detection of high‐ and low‐affinity inhibitors of a membrane enzyme in cell extracts and determination of their IC₅₀ values. Our approach can allow the discovery of novel binding fragments against targets known to be difficult to purify or where membrane‐association is required for activity. These results pave the way for future applications of the methodology to these relevant and complex biological systems.     

Plasma Phytosterol Half‐Life and Levels Are Increased in Very Low Birth Weight Preterm Infants with Parenteral Nutrition‐Associated Cholestasis

Parenteral nutrition‐associated cholestasis (PNAC) has been linked to plasma accumulation of phytosterols in infants receiving vegetable‐oil‐based lipid emulsions (LE). To date, information on the ability of infants with PNAC to metabolize intravenous (IV) phytosterols has been very limited. We characterized plasma phytosterol half‐life in very low birth weight (VLBW) preterm infants with PNAC. As part of a prospective cohort study, VLBW infants with PNAC underwent serial blood sample measurements of sitosterol (Sito), campesterol (Camp), and stigmasterol (Stigma). Infants without PNAC served as controls (CTRL, control infants). Thirty‐seven PNAC infants and 14 CTRL were studied. On PN day 7 and PN day 14, PNAC infants had higher plasma phytosterol concentrations compared to those of CTRL (p < 0.05). A significant and positive correlation was found between plasma Camp, Stigma, Sito concentrations, and IV phytosterol intake from birth to PN day 7 (p = 0.001, p = 0.001, and p = 0.005, respectively). Stigma concentration was positively correlated with conjugated bilirubin on PN day 7 (p = 0.012). After stopping IV LE, half‐lives of Camp, Stigma, and Sito became significantly longer in PNAC infants than in CTRL (Camp: 18.8 ±6.2 vs 11.8 ±3.0 days, p = 0.001; Stigma: 13.8 ±5.8 vs 9.4 ±3.4 days, p = 0.023; Sito: 15.3 ±5.0 vs 9.8 ±3.0 days, p = 0.002). In conclusion, phytosterols increased earlier during PN and were eliminated slowly after stopping IV LE in PNAC infants than in CTRL. The Stigma concentration on PN day 7 could represent an early marker of cholestasis. Our results provide additional evidence on the relationship between IV phytosterols and PNAC.     

Monthly Hydrological Indicators to Assess Possible Alterations on Rivers’ Flow Regime

Assessing potential deviations of the fundamental river basins’ hydrological processes and streamflow characteristics from the “natural trajectory” represents a high-priority objective to understand the biological impact of altered flow regime on river ecosystems. Existing approaches are mainly based on the analysis of daily-based indicators of hydrologic alteration, which requires wide database, including “pre-impact” and “post-impact” daily flow data frequently unavailable. The hydrological modeling is commonly used to face data missing problems or reconstruct natural conditions, even if models, especially at the daily scales, are often complex and computationally intensive. The use of simpler and more parsimonious models results, sometimes, essential for practical applications, also in consideration of the typical scarce availability of some data. This paper proposes an alternative approach for the evaluation of rivers flow regime alterations, based on different monthly hydrological indicators that are first computed and then combined to provide a global index of alteration. The procedure, conceptually derived from the Range of Variability Approach (RVA), is applied and tested on two Sicilian river basins (Italy) subject to anthropogenic influence. Streamflow regime for both the basins results differently disturbed by upstream human pressures. An alteration index is computed using available observations as “post-impact” monthly flow time-series, while time-series relative to “pre-impact” conditions have been reconstructed by the Tri.Mo.Ti.S. model, an innovative monthly and high-performing regional regressive hydrological model. The methodology, easily transferable to other regions, has revealed particularly efficacious in identifying and quantifying the existing human pressures and can be considered as a suitable tool for water resource management and policy planning activities.     

Intent‐based service management for heterogeneous software‐defined infrastructure domains

One of the main challenges in delivering end‐to‐end service chains across multiple software‐defined networking (SDN) and network function virtualization (NFV) domains is to achieve unified management and orchestration functions. A very critical aspect is the definition of an open, vendor‐agnostic, and interoperable northbound interface (NBI) that should be as abstract as possible and decoupled from domain‐specific data and control plane technologies. In this paper, we propose a reference architecture and an intent‐based NBI for end‐to‐end service management across multiple technological domains. The general approach is tested in a heterogeneous OpenFlow/Internet‐of‐Things (IoT) SDN test bed, where the proposed solution is applied to a rather complex service provisioning scenario spanning three different technological domains: an IoT infrastructure deployment, a cloud‐based data collection, processing, and publishing platform, and a transport domain over a geographic network interconnecting the IoT domain and the data center hosting the cloud services.     

Lineage‐Specific Commitment of Stem Cells with Organic and Graphene Oxide–Functionalized Nanofibers

Controlling the differentiation to certain lineages is the main goal of current stem cell research, which might exploit new routes based on the interaction of cells with nanomaterials. Here it is shown that primary neurospheres from dental pulp stem cells grown on combinatorial surfaces with different fibrous morphology and graphene oxide functionalization exhibit different differentiation propensity. The developed materials strongly influence the stem cell fate, as highlighted by morphological, immunofluorescence, molecular biology, and functional analyses. Instructive cues lead to the increased expression of markers that are characteristic of selective differentiation into osteoblasts, glial cells, fibroblasts, and neurons even in basal medium conditions, and randomly oriented fibers are found to revert neuronal precommitment and to trigger osteoblastic differentiation. Graphene oxide coatings lead instead to the relatively enhanced expression of genes typical of either glial or neuronal commitment, depending on the underlying nanofibrous morphology. The mechanisms addressing cell fate are investigated, highlighting the correlation of wetting anisotropy and protein adsorption capacity of different surfaces, ultimate cell conformational changes reflected by skeletal and nuclear elongation, and directed cell commitment. Cues from the different surfaces are therefore lineage‐specific, unveiling remarkable potentialities for cellular programming by means of nanomaterials.     

Age-related changes in the human thymus studied with scanning electron microscopy

This investigation describes some morphological, age-related changes in different compartments and cells of the human thymus. Scanning electron microscopic observations were done on human thymus samples obtained from four young and eight elderly patients during thoracic surgery and/or diagnostic biopsy of the thymus, after receiving authorization from the Ethical Committee of our university. The morphological data were submitted to quantitative image analysis so as to obtain quantitative results. Subsequently, the related values were used for statistical analysis. Our findings demonstrate that (1) all thymus compartments (subcapsular spaces, cortical, medullar, thymus microenvironment) contain numerous thymocytes even after the thymus has aged. (2) In older humans, residual thymus lymphoid islets contain, in addition to fatty cells and/or fibrous cells, also the same types of resident and nonresident cells (permanent and moving cells) that are found in young and adult subjects. (3) Endothelial cells of thymus microvessels contain numerous gaps. These gaps are tight in young subjects and become loose with age. (4) Thymocytes, in older subjects, are always found near these loose endothelial gaps of thymus microvessels. (5) While thymus cortical microvessels are provided with pericytes and/or periarteriolar spaces, microvessels of the thymus medullar are free of such spaces. Our morphological and quantitative results lead us to consider the possibility that the thymus fraction of resident and permanent cells (including thymocytes and reticular epithelial cells) is larger in younger subjects compared with older ones. The endothelial loose gaps of thymus microvessels, in older subjects, can allow the bidirectional transit of thymocytes through the wall of the said microvessels.     

Characterization of 12 Capsicum varieties by evaluation of their carotenoid profile and pungency determination

In this research 12 different varieties of Capsicum cultivars belonging to three species (Capsicum chinense, Capsicum annuum, Capsicum frutescens) and of various colour, shape, and dimension have been characterised by their carotenoids and capsaicinoids content. The berries were cultivated in the region Emilia-Romagna, in Northern Italy. The native carotenoid composition was directly investigated by an HPLC-DAD-APCI-MS methodology, for the first time. In total, 52 carotenoids have been identified and considerable variation in carotenoid composition was observed among the various cultivars investigated. Among the cultivars with red colour, some Habanero, Naga morich and Sinpezon showed an high β-carotene content, whereas Serrano, Tabasco and Jalapeno showed an high capsanthin content and the absence of β-carotene. Habanero golden and Scotch Bonnet showed a high lutein, α-carotene and β-carotene amounts, and Habanero orange was rich in antheraxanthin, capsanthin and zeaxanthin. Cis-cryptocapsin was present in high amount in Habanero chocolate.