Leitat Technological Center

Valencia, Spain

Leitat Technological Center

Valencia, Spain
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Guzman E.,Complutense University of Madrid | Mateos-Maroto A.,Complutense University of Madrid | Ruano M.,Leitat Technological Center | Ortega F.,Complutense University of Madrid | Rubio R.G.,Complutense University of Madrid
Advances in Colloid and Interface Science | Year: 2017

Soft assemblies obtained following the Layer-by-Layer (LbL) approach are accounted among the most interesting systems for designing biomaterials and drug delivery platforms. This is due to the extraordinary versatility and flexibility offered by the LbL method, allowing for the fabrication of supramolecular multifunctional materials using a wide range of building blocks through different types of interactions (electrostatic, hydrogen bonds, acid-base or coordination interactions, or even covalent bonds). This provides the bases for the building of materials with different sizes, shapes, compositions and morphologies, gathering important possibilities for tuning and controlling the physico-chemical properties of the assembled materials with precision in the nanometer scale, and consequently creating important perspective for the application of these multifunctional materials as cargo systems in many areas of technological interest. This review studies different physico - chemical aspects associated with the assembly of supramolecular materials by the LbL method, paying special attention to the description of these aspects playing a central role in the application of these materials as cargo platforms for encapsulation and release of active compounds. © 2017 Elsevier B.V.


Benedicto E.,Spanish University for Distance Education (UNED) | Benedicto E.,Leitat Technological Center | Carou D.,University College Dublin | Carou D.,University of Aveiro | Rubio E.M.,Spanish University for Distance Education (UNED)
Procedia Engineering | Year: 2017

The use of cutting fluids in machining processes is a serious concern because their cost, and environmental and health effects. In the last decades, efforts have been developed to come up with alternatives to overcome their main drawbacks. The ultimate goal is the complete suppression of cutting fluids. However, because of the demanding requirements of the machining processes, in some cases it is not possible to use dry machining conditions. Reasons can be found in the excessive heat generated in the process, the increase of the friction between the tool and the workpiece or the need to evacuate the chips generated. The pull for sustainable products is also encouraging the developing of new cutting fluid formulations. In the present paper, a comprehensive analysis of the use of cutting fluids and main alternatives in machining is carried out. Particularly, the analysis was done focusing on the economic, environmental and technical points. © 2017 The Authors. Published by Elsevier Ltd.


De Wever B.,Henkel AG | Fuchs H.W.,Biotechnologie Vertrieb GmbH | Gaca M.,G and nter | Krul C.,TNO | And 4 more authors.
Toxicology in Vitro | Year: 2012

At the IVTIP (In Vitro Testing Industrial Platform) meeting of November 26th 2009 entitled 'Toxicology in the 21st century ('21C') - working our way towards a visionary reality' all delegates endorsed the emerging concept of the '21C' vision as the way forward to enable a thorough, reliable and systematic approach to future toxicity testing without the use of animals. One of the emerging concepts focused on integrating a defined number of tests modelling in vivo-relevant and well-characterised toxicity pathways representing mechanistic endpoints. At this meeting the importance of Integrated Testing Strategies (ITS) as tools towards reduction and eventually replacement of the animals currently used for hazard identification and risk assessment was recognised.A follow-up IVTIP Spring 2010 meeting entitled 'Integrated In Vitro Testing Strategies (ITS) - Implementation Challenges' was organised to address pending questions about ITS. This report is not a review of the ITS literature, but a summary of the discussions triggered by presented examples on how to develop and implement ITS. Contrasts between pharmaceutical and chemical industry, as well as a list of general but practical aspects to be considered while developing an ITS emerged from the discussions. In addition, current recommendations on the validation of ITS were discussed.In conclusion, the outcome of this workshop improved the understanding of the participants of some important factors that may impact the design of an ITS in function of its purpose (e.g. screening, or early decision making versus regulatory), the context in which they need to be applied (e.g. ICH guidelines, REACH) and the status and quality of the available tools. A set of recommendations of best practices was established and the importance of the applicability of the individual tests as well as the testing strategy itself was highlighted. © 2012 Elsevier Ltd.


Bachmann J.,German Aerospace Center | Hidalgo C.,Leitat Technological Center | Bricout S.,Airbus
Science China Technological Sciences | Year: 2017

The forecast of growing air transport in the upcoming decades faces the challenge of an increasing environmental impact. Aviation industry is working on promising technologies to mitigate this environmental impact. Lightweight design is a strong lever to lower the fuel consumption and, consequently, with it the emissions of aviation. High performance composites are a key technology to help achieve these aims thanks to their favourable combination of mechanical properties and low weight in primary structures. However, mainly synthetic materials such as petrol based carbon fibres and epoxy resins are used nowadays to produce composite in aviation. Renewable materials like bio-based fibres and resin systems offer potential environmental advantages. However, they have not found their way into aviation, yet. The reasons are reduced mechanical properties and, especially for the use of natural fibres, their flammability. Improvements of these shortcomings are under investigation. Therefore the application of bio-based and recycled materials in certain areas of the aircraft could be possible in the future. Good examples for applications are furnishings and secondary structures. The motivation for this paper is to give an overview of potential environmental properties by using such eco-materials in aviation. Life cycle assessment (LCA) is a tool to calculate environmental impacts during all life stages of a product. The main focus is laid on the bio-fibres flax and ramie, recycled carbon fibres and bio-based thermoset resin systems. Furthermore an overview of environmental aspects of existing composite materials used in aviation is given. Generally, a lack of LCA results for the substitution of synthetic materials by bio-based/recycled composite materials in aviation applications has been identified. Therefore, available information from other transport areas, such as automotive, has been summarized. More detailed LCA data for eco-composite materials and technologies to improve their properties is important to understand potential environmental effects in aviation. © 2017 Science China Press and Springer-Verlag GmbH Germany


Perez-Guaita D.,University of Valencia | Kuligowski J.,University of Valencia | Quintas G.,Leitat Technological Center | Garrigues S.,University of Valencia | Guardia M.d.l.,University of Valencia
Talanta | Year: 2013

Locally weighted partial least squares regression (LW-PLSR) has been applied to the determination of four clinical parameters in human serum samples (total protein, triglyceride, glucose and urea contents) by Fourier transform infrared (FTIR) spectroscopy. Classical LW-PLSR models were constructed using different spectral regions. For the selection of parameters by LW-PLSR modeling, a multi-parametric study was carried out employing the minimum root-mean square error of cross validation (RMSCV) as objective function. In order to overcome the effect of strong matrix interferences on the predictive accuracy of LW-PLSR models, this work focuses on sample selection. Accordingly, a novel strategy for the development of local models is proposed. It was based on the use of: (i) principal component analysis (PCA) performed on an analyte specific spectral region for identifying most similar sample spectra and (ii) partial least squares regression (PLSR) constructed using the whole spectrum. Results found by using this strategy were compared to those provided by PLSR using the same spectral intervals as for LW-PLSR. Prediction errors found by both, classical and modified LW-PLSR improved those obtained by PLSR. Hence, both proposed approaches were useful for the determination of analytes present in a complex matrix as in the case of human serum samples. © 2013 Elsevier B.V. All rights reserved.


Kuligowski J.,University of Valencia | Quintas G.,Leitat Technological Center | Herwig C.,Vienna University of Technology | Lendl B.,Vienna University of Technology
Talanta | Year: 2012

This paper shows the ease of application and usefulness of mid-IR measurements for the investigation of orthogonal cell states on the example of the analysis of Pichia pastoris cells. A rapid method for the discrimination of entire yeast cells grown under carbon and nitrogen-limited conditions based on the direct acquisition of mid-IR spectra and partial least squares discriminant analysis (PLS-DA) is described. The obtained PLS-DA model was extensively validated employing two different validation strategies: (i) statistical validation employing a method based on permutation testing and (ii) external validation splitting the available data into two independent sub-sets. The Variable Importance in Projection scores of the PLS-DA model provided deeper insight into the differences between the two investigated states. Hence, we demonstrate the feasibility of a method which uses IR spectra from intact cells that may be employed in a second step as an in-line tool in process development and process control along Quality by Design principles. © 2012 Elsevier B.V.


Kuligowski J.,University of Valencia | Quintas G.,Leitat Technological Center | Tauler R.,CSIC - Institute of Chemical and Environmental Research | Lendl B.,Vienna University of Technology | De La Guardia M.,University of Valencia
Analytical Chemistry | Year: 2011

The use of multivariate curve resolution-alternating least-squares (MCR-ALS) in liquid chromatography-infrared detection (LC-IR) is troublesome due to the intense background absorption changes during gradient elution. Its use has been facilitated by previous removal of a significant part of the solvent background IR contributions due to common mobile phase systems employed during reversed phase gradient applications. Two straightforward background correction approaches based on simple-to-use interactive self-modeling mixture analysis (SIMPLISMA) and principal component analysis (PCA) are proposed and evaluated on reversed phase gradient LC-IR data sets obtained during the analysis of carbohydrate and nitrophenol mixtures. After subtraction of the calculated background signal, MCR-ALS provided improved signal-to-noise ratios, removed remaining mobile phase and background signal contributions, and resolved overlapping chromatographic peaks. The present approach tends to enable easy-to-use background correction to facilitate the use of MCR-ALS in online LC-IR, even in challenging situations when gradient conditions are employed and only poor chromatographic resolution is achieved. It, therefore, shows great potential to facilitate the full exploitation of the advantages of simultaneous quantification and identification of a vast amount of analytes employing online IR detection, making new exciting applications more accessible. © 2011 American Chemical Society.


Salvans S.,Hospital del Mar | Salvans S.,Colorectal Cancer Research Group | Mayol X.,Colorectal Cancer Research Group | Alonso S.,Hospital del Mar | And 9 more authors.
Annals of Surgery | Year: 2014

Objective: The aim of this study was to investigate the effect of postoperative peritoneal infection on proliferation, migration, and invasion capacities of cancer cells lines in vitro after surgery for colorectal cancer. Background: Anastomotic leakage is associated with higher rates of recurrence after surgery for colorectal cancer. However, the mechanisms responsible are unknown. We hypothesized that the infection-induced inflammatory response may enhance tumor progression features of residual cancer cells. Methods: Prospective matched cohort study. Patients undergoing surgery for colorectal cancer with curative intent (January 2008-March 2012) were included. Patients who had an anastomotic leak or intra-abdominal abscess were included in the infection group (n = 47). For each case patient, another patient with an uncomplicated postoperative course was selected for the control group (n = 47). In vitro treatments on cancer cell lines (MDA-MB-231 and SW620) were performed using baseline and postoperative serumand peritoneal fluid samples to determine cell proliferation and cell migration/invasion activities. Results: Postoperative peritoneal fluid from infected patients enhanced both cell migration (infection: 140 ± 85 vs control: 94 ± 30; P = 0.016) and cell invasion (infection: 117 ± 31 vs control: 103 ± 16; P = 0.024) capacities of cancer cell lines.With serum samples, these effects were only observed in cell migration assays (infection: 98 ± 28 vs control: 87 ± 17; P = 0.005). Some minor activation of cell proliferation was observed by treatment with serum from infection group. Two-year cumulative disease-free survival was significantly lower in patients with postoperative peritoneal infection (infection: 77.6% vs control: 90.6%; P = 0.032). Conclusions: Our results suggest that postoperative peritoneal infection enhances the invasive capacity of residual tumor cells after surgery, thus facilitating their growth to recurrent tumors. Copyright © 2014 by Lippincott Williams & Wilkins.


Camara R.M.,Technical University of Madrid | Crespo E.,Leitat Technological Center | Portela R.,ICP | Suarez S.,CIEMAT | And 3 more authors.
Catalysis Today | Year: 2014

Organic polymers are excellent substrates for photocatalytic applications of TiO2 thin films, which can be easily prepared by sol-gel synthesis followed by dip coating. However, the wettability of the hydrophobic surface of polymers should be improved. In this work, commercial poly(vinyl chloride) (PVC), poly(methyl methacrylate) (PMMA) and polystyrene (PS) were selected according to their high transmittance in the TiO2 activation range for the immobilization of the semiconductor. Low pressure (LPP) and atmospheric pressure (APP) plasma were used to modify the surface properties of the organic polymers to improve the affinity for TiO2 aqueous sols and solutions. The characterization of the materials was performed by atomic force microscopy (AFM), UV-Vis spectroscopy, and contact angle and surface tension measurements, employed to evaluate wettability of the samples. The effect of the power of discharge and treatment time on the induced surface properties was analyzed. LPP at 300 W during 600 s was found as adequate treatment to promote the hydrophilicity of all samples without damage to the bulk. The adhesion of TiO2 thin films on the polymers was improved with the plasma pre-treatment due to the generation of roughness and specific polar functional groups. Accordingly, the photocatalytic performance increased with respect to the non-treated substrates, reaching similar conversion values than the reference photocatalyst where glass, a hydrophilyc substrate, was used as support. © 2013 Elsevier B.V.


Kenzaoui B.H.,University of Lausanne | Vila M.R.,Leitat Technological Center | Miquel J.M.,Leitat Technological Center | Cengelli F.,University of Lausanne | Juillerat-Jeanneret L.,University of Lausanne
International Journal of Nanomedicine | Year: 2012

Nanoparticles (NPs) are in clinical use or under development for therapeutic imaging and drug delivery. However, relatively little information exists concerning the uptake and transport of NPs across human colon cell layers, or their potential to invade three-dimensional models of human colon cells that better mimic the tissue structures of normal and tumoral colon. In order to gain such information, the interactions of biocompatible ultrasmall superparamagnetic iron oxide nanoparticles (USPIO NPs) (iron oxide core 9-10 nm) coated with either cationic polyvinylamine (aminoPVA) or anionic oleic acid with human HT-29 and Caco-2 colon cells was determined. The uptake of the cationic USPIO NPs was much higher than the uptake of the anionic USPIO NPs. The intracellular localization of aminoPVA USPIO NPs was confirmed in HT-29 cells by transmission electron microscopy that detected the iron oxide core. AminoPVA USPIO NPs invaded three-dimensional spheroids of both HT-29 and Caco-2 cells, whereas oleic acid-coated USPIO NPs could only invade Caco-2 spheroids. Neither cationic aminoPVA USPIO NPs nor anionic oleic acid-coated USPIO NPs were transported at detectable levels across the tight CacoReady™ intestinal barrier model or the more permeable mucus-secreting CacoGoblet™ model. © 2012 Halamoda Kenzaoui et al, publisher and licensee Dove Medical Press Ltd.

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