San Donato Milanese, Italy
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Reynaud C.,Grenoble Institute of Technology | Tapin-Lingua S.,Grenoble Institute of Technology | Elegir G.,Innovhub ssi | Petit-Conil M.,Grenoble Institute of Technology | Baumberger S.,French National Institute for Agricultural Research
Journal of Biotechnology | Year: 2013

Hydrophobic properties were conferred to a high-lignin-content Kraft pulp by a laccase-catalysed treatment in the presence of lauryl gallate (LG). The treatment resulted in a two-fold increase in contact angle and conferred water absorption resistance to the pulp. Kappa number was increased, indicating that some phenolic compounds were incorporated in the pulp. A control treatment with LG alone did not affect water absorption, demonstrating that laccase was essential to attain these new properties. The loss of hydrophobicity after an acetone Soxhlet extraction highlighted that adsorbed acetone-soluble compounds played a key role in the properties. GC-FID and HPSEC-UV analysis of the acetone extract indicated the formation of dodecanol and different phenolic oligomers. SEM images showed the treatment-induced changes in the fibre network. Additional experiments with various reaction times and reactant concentrations highlighted the role of LG oxidation products in the introduction of absorption resistance. © 2013 Elsevier Ltd.V.

Marelli B.,Polytechnic of Milan | Achilli M.,Laval University | Alessandrino A.,INNOVHUB SSI | Freddi G.,INNOVHUB SSI | And 3 more authors.
Macromolecular Bioscience | Year: 2012

None of the replacements proposed in the literature for small-calibre blood vessels (SCBV) fully satisfies the stringent requirements that these grafts have to fulfil. Here, an electrospun silk fibroin tubular construct is hybridized with type I collagen gel to produce a biomimetic SCBV graft with physiologically relevant compliance and burst pressure and optimal cytocompatibility. The hybridization of the two polymers results in the formation of a nanofibrillar hydrated matrix, where the collagen gel enhances the mechanical properties of the SF tubular construct and improves the early response of the material to in vitro cell adhesion and proliferation. An electrospun silk fibroin tubular construct is hybridized with type I collagen gel to produce a scaffold with potential applications as small calibre blood vessel graft. The proposed nanofibrillar tube possesses mechanical properties (i.e., compliance) comparable to the one of saphenous veins and favors the early response of the material to cell culturing. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Saini S.,University Grenoble Alpes | Saini S.,French National Center for Scientific Research | Belgacem N.,University Grenoble Alpes | Belgacem N.,French National Center for Scientific Research | And 4 more authors.
ACS Applied Materials and Interfaces | Year: 2015

Contact active surfaces are an innovative tool for developing antibacterial products. Here, the microfibrillated cellulose (MFC) surface was modified with the β-lactam antibiotic benzyl penicillin in aqueous medium to prepare antimicrobial films. Penicillin was grafted on the MFC surface using a suspension of these nanofilaments or directly on films. Films prepared from the penicillin-modified MFC were characterized by Fourier transform infrared spectroscopy, contact angle measurements, elemental analysis, and X-ray photoelectron spectroscopy and tested for antibacterial activity against the Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Penicillin-grafted MFC films exhibited successful killing effect on Gram-positive bacteria with 3.5-log reduction whereas bacteriostatic efficiency was found in penicillin-grafted MFC suspension. The zone of inhibition test and leaching dynamic assay demonstrated that penicillin was not diffused into the surrounding media, thus proving that the films were indeed contact active. Thus, penicillin can be chemically bound to the modified substrate surface to produce promising nonleaching antimicrobial systems. © 2015 American Chemical Society.

PubMed | INNOVHUB SSI, Irccs Instituto Of Ricerche Farmacologiche Mario Negri, Polytechnic of Milan and University of Bergamo
Type: | Journal: Materials science & engineering. C, Materials for biological applications | Year: 2015

To overcome the drawbacks of autologous grafts currently used in clinical practice, vascular tissue engineering represents an alternative approach for the replacement of small diameter blood vessels. In the present work, the production and characterization of small diameter tubular matrices (inner diameter (ID)=4.5 and 1.5 mm), obtained by electrospinning (ES) of Bombyx mori silk fibroin (SF), have been considered. ES-SF tubular scaffolds with ID=1.5 mm are original, and can be used as vascular grafts in pediatrics or in hand microsurgery. Axial and circumferential tensile tests on ES-SF tubes showed appropriate properties for the specific application. The burst pressure and the compliance of ES-SF tubes were estimated using the Laplaces law. Specifically, the estimated burst pressure was higher than the physiological pressures and the estimated compliance was similar or higher than that of native rat aorta and Goretex prosthesis. Enzymatic in vitro degradation tests demonstrated a decrease of order and crystallinity of the SF outer surface as a consequence of the enzyme activity. The in vitro cytocompatibility of the ES-SF tubes was confirmed by the adhesion and growth of primary porcine smooth muscle cells. The in vivo subcutaneous implant into the rat dorsal tissue indicated that ES-SF matrices caused a mild host reaction. Thus, the results of this investigation, in which comprehensive morphological and mechanical aspects, in vitro degradation and in vitro and in vivo biocompatibility were considered, indicate the potential suitability of these ES-SF tubular matrices as scaffolds for the regeneration of small diameter blood vessels.

PubMed | University of Turin, Innovhub SSI and Catholic University of Louvain
Type: Journal Article | Journal: Preparative biochemistry & biotechnology | Year: 2016

The production of laccases from Trametes pubescens was investigated along with the role of nutrients and elicitors. Copper proved to be a fundamental inducer, although productivity yields were consistently enhanced only in the presence of additional compounds (textile dyes). Using a central composite design, the optimal culture condition was examined, by taking into consideration the three distinct variables and their combinatorial effect. The 290Uml(-1) of laccases were produced after setting nitrogen, copper, and reactive blue 19 concentration; in a bioreactor, activity recovery was lower (90Uml(-1)) and pellet morphology was different. The activity of the laccase crude extract was maximal at 60C and stable for 14h at 50C and for 2 months at pH 6 and room temperature. The biotechnological potential was assessed, confirming the capacity to decolorize single or mixed solutions of textile dyes and to enhance the whitening yield of raw cotton fibers, working in synergism with the conventional H2O2-based method.

PubMed | Innovhub SSI, University of L'Aquila, Italian Institute of Technology, Unita Operativa di Oculistica and Irccs Azienda Ospedaliera San Martino Ist Instituto Nazionale Per La Ricerca Sul Cancro
Type: Journal Article | Journal: Advanced healthcare materials | Year: 2016

Replacement strategies arise as promising approaches in case of inherited retinal dystrophies leading to blindness. A fully organic retinal prosthesis made of conjugated polymers layered onto a silk fibroin substrate is engineered. First, the biophysical and surface properties are characterized; then, the long-term biocompatibility is assessed after implantation of the organic device in the subretinal space of 3-months-old rats for a period of five months. The results indicate a good stability of the subretinal implants over time, with preservation of the physical properties of the polymeric layer and a tight contact with the outer retina. Immunoinflammatory markers detect only a modest tissue reaction to the surgical insult and the foreign body that peaks shortly after surgery and progressively decreases with time to normal levels at five months after implantation. Importantly, the integrity of the polymeric layer in direct contact with the retinal tissue is preserved after five months of implantation. The recovery of the foreign-body tissue reaction is also associated with a normal b-wave in the electroretinographic response. The results demonstrate that the device implanted in nondystrophic eyes is well tolerated, highly biocompatible, and suitable as retinal prosthesis in case of photoreceptor degeneration.

Perrone M.G.,University of Milan Bicocca | Carbone C.,CNR Institute of atmospheric Sciences and Climate | Faedo D.,INNOVHUB SSI | Ferrero L.,University of Milan Bicocca | And 3 more authors.
Atmospheric Environment | Year: 2014

EU emission standards for vehicles do not include many particulate (PM) and gaseous species, despite their considerable impact on air pollution and health. Emission factors (EFs) were measured for unregulated species, i.e. polycyclic aromatic hydrocarbons (PAHs) and n-alkanes (ALKs) in the particle phase, and, for the first time, EFs for phenols in both particle and gas phases. Exhaust samples were collected under controlled operating conditions (chassis dynamometer tests) for in-service vehicles (private cars, PCs and light duty vehicles, LDVs) from different EURO classes. EFs of trace organics were highest for the old EURO 1 vehicles (the tested EURO 1 vehicles were without emission-control devices), and lowest for the more recent EURO 3 and 4 vehicles. ALKs (C20-C32) were the most abundant trace organic compounds found in PM vehicle exhaust, and their EF ranged between 2034 and 101μgkm-1 (Euro 1-4 LDVs). PM-phased phenols EFs were in the range 0.42-2.50μgkm-1, and 4-nitrophenol was the most abundant one. The highest EFs were measured for phenols in the gas phase (dominated by the presence of phenol) for gasoline EURO 1 (43.16±9.99μgkm-1). Emissions of PAHs changed depending on the fuel used. The PAH EFs of diesel-driven PCs were 4-5 times higher than those of gasoline vehicles, with PAHs diesel exhaust being mainly enriched in low 4-ring PAHs (85%), while 5-6 ring PAHs were prevalent (55%) in gasoline vehicles. Results of source profiles from chassis dynamometer tests were compared with ambient data, and the traffic PAH source profile derived from a tunnel study (Milan) agreed with the estimated emissions from a mix of diesel and gasoline vehicles circulating in the same area. Moreover, the impact of EURO regulatory changes on exhaust emissions was calculated, and this made it possible to estimate the downward trend of PAH emissions in the Province of Milan in the period 2005-2020. © 2013 Elsevier Ltd.

Dellavedov M.,Innovhub SSI | Pasturenzi C.,Innovhub SSI | Gigante L.,Innovhub SSI | Lunghi A.,Innovhub SSI
Chemical Engineering Transactions | Year: 2012

Current legislation about goods carriage (ADR-Agreement Concerning the International Carriage of Dangerous Goods by Road) sets the determination of several parameters related to the conditions of the used containers. Several of these parameters are required for the substance classification and the definition of the precautions to be adopted during transportation. One of the main potential hazards during freight is related to the thermal decomposition of the substance. Testing for the identification of decomposition in the carriage conditions can be time consuming and expensive, therefore different solutions have been attempted to simulate thermal behaviour of chemical compounds during transportation. This work focuses on the analysis of such methods and, in particular, on the model free methods for the determination of the decomposition kinetic of the studied compounds. This model is able to fit the kinetic behaviour of complex decomposition mechanisms more than others. The kinetic developed can be subsequently used to develop predictive models for the evaluation of transportation parameters, as for example the Self Accelerating Decomposition Temperature-SADT, but also to track the product quality during time aging. Input data for this analysis are Differential Scanning Calorimetric (DSC) tests. They are safe, quick and cheap and can give important information about thermal behaviour of the studied substances. The model free methodology and the SADT determination has been performed for the decomposition of two different organic peroxides and a solid compound. Copyright © 2012, AIDIC Servizi S.r.l.

The E.C Regulation CE 61/2011 has introduced a new quality parameter for extra virgin olive oil, the alkylesters. It is widely argued that the alkylesters may increase during the storage due to the reaction between free fatty acids and methyl and ethyl alcohols naturally present in the oil. In the experience here reported, we have verified the increase of alkylesters in some stored commercial oils coming from both Italy and the European Community. We have also verified the methyl and ethyl alcohol content as well as the variation of the content in waxes, which are known to increase during storage time.

The present study is aimed evaluating the use of different injection techniques in gas chromatography (on-column, split and PTV injection) for the analysis of the triglyceride fraction of cocoa butter. The comparison was performed by injecting a certified reference material of cocoa butter and evaluating the instrumental response factors of the main triglycerides. In addition, the chromatographic resolution between some critical pairs of triglycerides was evaluated. The results obtained showed that the on-column injection was the most recommended technique but it did not provide statistically different results compared to the other two techniques, split and PTV. This only after a careful optimization of GC conditions in order to minimize the discrimination against the triglyceride components of the cocoa butter. Several samples of plain chocolates were analyzed in order to identify the presence of cocoa butter equivalents. The method of analysis used was the one proposed by the researchers of IRMM. Almost all the samples analyzed contained only cocoa butter with the exception of a single sample which was found to be added with vegetable fats. Further investigations were still needed in order to confirm this result and the use of additional analytical methods could provide valuable support. © 2015 GENAIO/MARZO.

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