Antibacterial Layer-by-Layer coatings for medical implants

The widespread occurrence of nosocomial infections and the emergence of new bacterial strands calls for the development of antibacterial coatings with localized antibacterial action that are capable of facing the challenges posed by increasing bacterial resistance to antibiotics. The Layer-by-Layer (LbL) technique, based on the alternating assembly of oppositely charged polyelectrolytes, can be applied for the non-covalent modification of multiple substrates, including medical implants. Polyelectrolyte multilayers fabricated by the LbL technique have been extensively researched for the development of antibacterial coatings as they can be loaded with antibiotics, antibacterial peptides, nanoparticles with bactericide action, in addition to being capable of restricting adhesion of bacteria to surfaces. In this review, the different approaches that apply LbL for antibacterial coatings, emphasizing those that can be applied for implant modification are presented.This research was funded by the MAT2017-88752-R Retos project from the Spanish Ministry of Economics. This work was performed under the Maria de Maeztu Units of Excellence Program from the Spanish State Research Agency–Grant No. MDM-2017-0720

Spontaneous confocal Raman microscopy--a tool to study the uptake of nanoparticles and carbon nanotubes into cells

Confocal Raman microscopy as a label-free technique was applied to study the uptake and internalization of poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) and carbon nanotubes (CNTs) into hepatocarcinoma human HepG2 cells. Spontaneous confocal Raman spectra was recorded from the cells exposed to oxidized CNTs and to PLGA NPs. The Raman spectra showed bands arising from the cellular environment: lipids, proteins, nucleic acids, as well as bands characteristic for either PLGA NPs or CNTs. The simultaneous generation of Raman bands from the cell and nanomaterials from the same spot proves internalization, and also indicates the cellular region, where the nanomaterial is located. For PLGA NPs, it was found that they preferentially co-localized with lipid bodies, while the oxidized CNTs are located in the cytoplasm

Polarity studies of single polyelectrolyte layers in polyelectrolyte multilayers probed by steady state and life time doxorubicin fluorescence

Hypothesis: Polarity in polyelectrolyte multilayers (PEMs) may vary from the inner to the top layers of the film as the charge compensation of the layers is more effective inside the PEMs than in outer layers. Doxorubicin hydrochloride (DX) is used here to sense polarity at the single polyelectrolyte level inside PEMS. Experimental: DX is complexed electrostatically to a polyanion, either polystyrene sulfonate (PSS) or polyacrylic acid (PAA) and assembled at selected positions in a multilayer of the polyanion and polyally lamine hydrochloride (PAH) as polycation. Local polarity in the layer domain is evaluated through changes in the intensity ratio of the first to second band of spectra of DX (I1/I2 ratio) by steady state flu orescence, and by Lifetime fluorescence. Findings: PAH/PSS multilayers, show a polarity similar to water with DX/PSS as top layer, decreasing to I1/ I2 ratios similar to organic solvents as the number of polyelectrolyte layers assembled on top increases. For PAH/PAA multilayers, polarity values reflect a more polar environment than water when DX/PAA is the top layer, remaining unaltered by the assembly of polyelectrolyte layers on top. Results show that different polar environments may be present in a PEM when considering polarity at the single layer level.Fil: Martinelli, Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Física del Sur. Universidad Nacional del Sur. Departamento de Física. Instituto de Física del Sur; Argentina. Centro de Investigación Cooperativa en Biomateriales; EspañaFil: Tasca, Elisamaria. Centro de Investigación Cooperativa en Biomateriales; España. Università degli Studi di Roma "La Sapienza"; ItaliaFil: Andreozzi, Patrizia. Università degli Studi di Firenze; Dipartimento di Chimica “Ugo Schiff”; Italia. Centro de Investigación Cooperativa en Biomateriales; EspañaFil: Libertone, Sara. Centro de Investigación Cooperativa en Biomateriales; EspañaFil: Ritacco, Hernán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Física del Sur. Universidad Nacional del Sur. Departamento de Física. Instituto de Física del Sur; ArgentinaFil: Giustini, Mauro. Università degli Studi di Roma "La Sapienza"; Italia. Università degli Studi di Firenze; Dipartimento di Chimica “Ugo Schiff” ; ItaliaFil: Moya, Sergio Enrique. Centro de Investigación Cooperativa en Biomateriales; España. Università degli Studi di Roma "La Sapienza"; Itali

Evolución de los modelos de la gestión de innovación (Evolution of innovation administration models)

Abstract. In this study the tools are analyzed to cause that the PyMEs looks for to be more competitive in the market. The different proposals will appear on the Models of the Innovation Process from already existing and they will focus in the variables that conform these models compatible to analyze each one of the proposals made by the different authors and to integrate a new proposal of variables as a hypothesis that integrates a Model that allows the Pymes of Nuevo Leon to be innovating. Resumen. En este estudio se analizan las herramientas para hacer que las PyMEs busquen ser más competitivas en el mercado. Se presentarán las diferentes propuestas sobre los Modelos de Gestión de la Innovación ya existentes y se enfocarán en las variables que conforman estos modelos afín de analizar cada una de las propuestas realizadas por los distintos autores e integrar una nueva propuesta de variables como hipótesis que integre un Modelo que permita a las Pymes de Nuevo León ser innovadoras

Creatividad organizacional como un factor clave en el proceso de gestión de la innovación para el desarrollo de nuevos productos, sector de estudio las PyMEs (Organizational creativity as a key element in the process of innovation management for new product development, SME sector study)

Abstract. The purpose of this study is to analyze organizational creativity as a key element in the process of product innovation. Analyzing some manage models for organizational creativity presented by various authors who have studied this phenomenon. Also, this element of Organizational Creativity stems from a doctoral study in which this variable is considered as the contribution to a new management model for the innovation process in developing new products for the SME sector. The analysis of results and conclusions are derived from a study of 34 samples to the industry of information technology in Nuevo León, México. Resumen. El propósito del estudio es analizar a la creatividad organizacional como un elemento clave en el proceso de innovación de producto. Se analizan los modelos existentes para gestionar a la creatividad organizacional, presentando las diferentes propuestas por distintos autores que han estudiado este fenómeno. Así mismo, este elemento de Creatividad Organizacional se deriva de un estudio doctoral en el que esta variable es considerada como el aporte a un nuevo modelo de gestión para el proceso de innovación en el desarrollo de nuevos productos para el sector de las PyMEs. El análisis de resultados y las conclusiones se presentan a partir de un estudio de 34 muestras a la industria de las tecnologías de la información en Nuevo León, México

Growth of radiata pine families in nursery and two years after field establishment

Pinus radiata D. Don is the most widely planted exotic species in Australia, Chile, New Zealand and Spain. In this study, growth and survival of P. radiata were compared in 30 open pollinated families grown under two contrasting watering regimes in nursery (well-watered cf. water-stress conditions) and planted on a drought-prone site with Mediterranean climate in central Chile. This study assessed phenotypic plasticity in growth and survival at nursery stage and two years after establishment in the field. Family plasticity at nursery stage was estimated by the angular phenotypic change index (APCI), while the relationship between nursery and field traits was estimated by genetic correlations (rg ) and the Pearson coefficient of correlation (rxy). Families presented high plasticity in diameter, height, and survival at nursery stage. Out of 30 families, eight exhibited over 80 % survival in the well-watered treatment, but less than 20 % survival in the water-stress treatment. As expected, growth traits and survival were positively correlated (rg and rxy > 0.65) between both nursery environments. However, for growth, most genetic and phenotypic correlations between combinations of nursery treatments versus the field test were negative or not significant. As there was no detectable pattern of nursery–field correlations regarding to combinations of nursery treatments and test site, the need to include more stable families and genotypes to an appropriate developmental stage at nursery is discussed

Dual monitoring of surface reactions in real time by combined surface-plasmon resonance and field-effect transistor interrogation

By combining surface plasmon resonance (SPR) and electrolyte gated field-effect transistor (EG-FET) methods in a single analytical device we introduce a novel tool for surface investigations, enabling simultaneous measurements of the surface mass and charge density changes in real time. This is realized using a gold sensor surface that simultaneously serves as a gate electrode of the EG-FET and as the SPR active interface. This novel platform has the potential to provide new insights into (bio)adsorption processes on planar solid surfaces by directly relating complementary measurement principles based on (i) detuning of SPR as a result of the modification of the interfacial refractive index profile by surface adsorption processes and (ii) change of output current as a result of the emanating effective gate voltage modulations. Furthermore, combination of the two complementary sensing concepts allows for the comparison and respective validation of both analytical techniques. A theoretical model is derived describing the mass uptake and evolution of surface charge density during polyelectrolyte multilayer formation. We demonstrate the potential of this combined platform through the observation of layer-bylayer assembly of PDADMAC and PSS. These simultaneous label-free and real-time measurements allow new insights into complex processes at the solid−liquid interface (like non-Fickian ion diffusion), which are beyond the scope of each individual tool.Fil: Aspermair, Patrik. Austrian Institute of Technology; Austria. CEST Competence Center for Electrochemical Surface Technologies; Austria. Centre National de la Recherche Scientifique; Francia. Universite Valencienne; Francia. Universite Lille; FranciaFil: Ramach, Ulrich. CEST Competence Center for Electrochemical Surface Technologies; AustriaFil: Reiner Rozman, Ciril. Austrian Institute of Technology; AustriaFil: Fossati, Stefan. Austrian Institute of Technology; AustriaFil: Lechner, Bernadette. Austrian Institute of Technology; AustriaFil: Moya, Sergio Enrique. Centro de Investigación Cooperativa en Biomateriales - CIC biomaGUNE; EspañaFil: Azzaroni, Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Dostalek, Jakub. Austrian Institute of Technology; AustriaFil: Szunerits, Sabine. Centre National de la Recherche Scientifique; Francia. Universite Valencienne; Francia. Universite Lille; FranciaFil: Knoll, Wolfgang. Austrian Institute of Technology; Austria. CEST Competence Center for Electrochemical Surface Technologies; AustriaFil: Bintinger, Johannes. Austrian Institute Of Technology; Austri

Novel Core–Shell Polyamine Phosphate Nanoparticles Self-Assembled from PEGylated Poly(allylamine hydrochloride) with Low Toxicity and Increased In Vivo Circulation Time

An approach for reducing toxicity and enhancing therapeutic potential of supramolecular polyamine phosphate nanoparticles (PANs) through PEGylation of polyamines before their assembly into nanoparticles is presented here. It is shown that the number of polyethylene glycol (PEG) chains for polyamine largely influence physico-chemical properties of PANs and their biological endpoints. Poly(allylamine hydrochloride) (PAH) are functionalized through carbodiimide chemistry with three ratios of PEG molecules per PAH chain: 0.1, 1, and 10. PEGylated PAH is then assembled into PANs by exposing the polymer to phosphate buffer solution. PANs decrease size and surface charge with increasing PEG ratios as evidenced by dynamic light scattering and zeta potential measurements, with the ten PEG/PAH ratio PANs having practically zero charge. Small angle X-ray scattering (SAXS) proves that PEG chains form a shell around a polyamine core, which is responsible for the screening of positive charges. MTT experiments show that the screening of amine groups decreases nanoparticle toxicity, with the lowest toxicity for the 10 PEG/PAH ratio. Fluorescence correlation spectroscopy (FCS) proves less interaction with proteins for PEGylated PANs. Positron emission tomography (PET) imaging of 18F labelled PANs shows longer circulation time in healthy mice for PEGylated PANs than non-PEGylated ones.Fil: Andreozzi, Patrizia. Basque Research and Technology Alliance; España. Università degli Studi di Firenze; ItaliaFil: Simó, Cristina. Basque Research and Technology Alliance; EspañaFil: Moretti, Paolo. Università Politecnica delle Marche; ItaliaFil: Martinez Porcel, Joaquin. Basque Research and Technology Alliance; EspañaFil: Lüdtke, Tanja Ursula. Basque Research and Technology Alliance; EspañaFil: Ramirez, Maria de Los Angeles. Basque Research and Technology Alliance; España. Universidad Nacional de San Martin. Instituto de Nanosistemas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tamberi, Lorenza. Basque Research and Technology Alliance; EspañaFil: Marradi, Marco. Università degli Studi di Firenze; ItaliaFil: Amenitsch, Heinz. Graz University Of Technology.; AustriaFil: Llop, Jordi. Basque Research and Technology Alliance; España. Centro de Investigación Biomédica En Red de Enfermedades Respiratorias; EspañaFil: Ortore, Maria Grazia. Università Politecnica Delle Marche; ItaliaFil: Moya, Sergio Enrique. Basque Research and Technology Alliance; Españ

BSA-capped gold nanoclusters as potential theragnostic for skin diseases: Photoactivation, skin penetration, in vitro, and in vivo toxicity

BSA-capped gold nanoclusters are promising theragnostic systems that can be excited to render both fluorescence emission and reactive oxygen species. Although their synthesis and photoluminescence properties are already well described, more accurate information about their use as photosensitizers is required in order to advance towards health applications. In this work, we have obtained BSA-capped gold nanoclusters and characterized their photophysics by different techniques. Singlet oxygen production was detected upon irradiation, which was enough to produce toxicity on two cell lines. Remarkably, an internal energy transfer, probably due to the presence of smaller nanoclusters and the contribution of oxidized residues of BSA in the system, caused fluorescence emission near 640 nm after excitation in the UV range. Additionally, the system was capable of penetrating human skin beyond the stratum corneum, which enhances the potential of these nanoclusters as bifunctional photodynamic therapy effectors and biomarkers with application in a diversity of skin diseases. In the absence of radiation, BSA-capped gold nanoclusters did not cause toxicity in vitro, while their toxic effect on an in vivo model as zebrafish was determined.Fil: Lillo, Rolando Cristian Rodrigo. Universidad Nacional de San Martin. Instituto de Nanosistemas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Calienni, Maria Natalia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Rivas Aiello, Maria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Prieto, Maria Jimena. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Rodriguez, Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Tuninetti, Jimena Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Toledo, Pamela Ludmila. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Alonso, Silvia del Valle. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Moya, Sergio Enrique. Centro de Investigación Cooperativa en Biomateriales; España. Centro de Investigación Cooperativa en Biomateriales; EspañaFil: Gonzalez, Monica Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Martinetti Montanari, Jorge Anibal. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Soler Illia, Galo Juan de Avila Arturo. Universidad Nacional de San Martin. Instituto de Nanosistemas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

A real-time PCR assay for detection of low Pneumocystis jirovecii levels

Here we report a new real-time PCR assay using SYBR Green which provides higher sensitivity for the specific detection of low levels of Pneumocystis jirovecii. To do so, two primer sets were designed, targeting the family of genes that code for the most abundant surface protein of Pneumocystis spp., namely the major surface glycoproteins (Msg), and the mitochondrial large subunit rRNA (mtLSUrRNA) multicopy gene, simultaneously detecting two regions. PCR methods are instrumental in detecting these low levels; however, current nested-PCR methods are time-consuming and complex. To validate our new real-time Msg-A/mtLSUrRNA PCR protocol, we compared it with nested-PCR based on the detection of Pneumocystis mitochondrial large subunit rRNA (mtLSUrRNA), one of the main targets used to detect this pathogen. All samples identified as positive by the nested-PCR method were found positive using our new real-time PCR protocol, which also detected P. jirovecii in three nasal aspirate samples that were negative for both rounds of nested-PCR. Furthermore, we read both rounds of the nested-PCR results for comparison and found that some samples with no PCR amplification, or with a feeble band in the first round, correlated with higher Ct values in our real-time Msg-A/mtLSUrRNA PCR. This finding demonstrates the ability of this new single-round protocol to detect low Pneumocystis levels. This new assay provides a valuable alternative for P. jirovecii detection, as it is both rapid and sensitive.This research was funded by the ERANet LAC (ELAC2014/HID-0254), the National Fund for Science and Technology (Fondecyt, Chile) (1140412), the Spanish Ministry of Science and Innovation (PID2019-105969GB-I00), Generalitat Valenciana (Spain) (Prometeo/2018/A/133), and co-financed by the European Regional Development Fund (ERDF, EU).Peer reviewe