Factors affecting mass transport properties of poly(Ɛ-caprolactone) membranes for tissue engineering bioreactors

High porosity and mass transport properties of microfiltration polymeric membranes benefit nutrients supply to cells when used as scaffolds in interstitial perfusion bioreactors for tissue engineering. High nutrients transport is assumed when pore size and porosity of the membrane are in the micrometric range. The present work demonstrates that the study of membrane fouling by proteins present in the culture medium, though not done usually, should be included in the routine testing of new polymer membranes for this intended application. Two poly(ε-caprolactone) microfiltration membranes presenting similar average pore size (approximately 0.7 µm) and porosity (>80%) but different external surface porosity and pore size have been selected as case studies. The present work demonstrates that a membrane with lower surface pore abundance and smaller external pore size (approximately 0.67 µm), combined with adequate hydrodynamics and tangential flow filtration mode is usually more convenient to guarantee high flux of nutrients. On the contrary, having large external pore size (approximately 1.70 µm) and surface porosity would incur important internal protein fouling that could not be prevented with the operation mode and hydrodynamics of the perfusion system. Additionally, the use of glycerol in the drying protocols of the membranes might cause plasticization and a consequent reduction of mass transport properties due to membrane compaction by the pressure exerted to force perfusion. Therefore, preferentially, drying protocols that omit the use of plasticizing agents are recommended.This research was funded by the Spanish Ministry of Economy and Competitiveness (MINECO, SPAIN-FEDER 2014–2020) through project CTM2016-75509-R

Facile fabrication of poly(e-caprolactone)/graphene oxide membranes for bioreactors in tissue engineering

Promising polymer membranes of blended biocompatible poly(ε-caprolactone) and graphene oxide (PCL/GO) and PCL and partially reduced graphene oxide (PCL/rGO) with outstanding water and nutrient transport properties for cell culture bioreactors were prepared using phase inversion at mild temperatures. Some of the prepared PCL/GO membranes were subjected to a 'chemical-free' GO post-reductive process using UV (PCL/GO/UV) irradiation. The PCL/rGO membranes exhibited 2.5 times higher flux than previously reported biocompatible polymer membranes for cell culture bioreactors, which was attributed to the highly interconnected porosity. On the other hand, the formation of PCL-graphene oxide composites in the PCL/GO and PCL/GO/UV membranes was not conclusive according to spectroscopic analyses, thermal analyses and mechanical characterization, probably due to the low graphene oxide loading in the membranes (0.1%w/w). The presence of graphene oxide-based nanomaterials in the polymer matrix slightly reduced the mechanical properties of the PCL-graphene oxide membranes by limiting the polymer chain mobility in comparison to that of the plain PCL membranes. However, their mechanical stability was sufficient for the applications pursued. Finally, the biocompatibility assay indicated that the incorporation of GO and rGO into the PCL matrix enhanced the uniform distribution and morphology of the glioblastoma cells on the surface of the PCL-graphene oxide membranes.Financial support of the Cantabria Explora call through project JP03.640.69 is gratefully acknowledged

Scaffold coupling: ERK activation by trans-phosphorylation across different scaffold protein species.

RAS-ERK (extracellular signal-regulated kinase) pathway signals are modulated by scaffold proteins that assemble the components of different kinase tiers into a sequential phosphorylation cascade. In the prevailing model scaffold proteins function as isolated entities, where the flux of phosphorylation events progresses downstream linearly, to achieve ERK phosphorylation. We show that different types of scaffold proteins, specifically KSR1 (kinase suppressor of Ras 1) and IQGAP1 (IQ motif-containing guanosine triphosphatase activating protein 1), can bind to each other, forming a complex whereby phosphorylation reactions occur across both species. MEK (mitogen-activated protein kinase kinase) bound to IQGAP1 can phosphorylate ERK docked at KSR1, a process that we have named trans-phosphorylation. We also reveal that ERK trans-phosphorylation participates in KSR1-regulated adipogenesis, and it also underlies the modest cytotoxicity exhibited by KSR-directed inhibitors. Overall, we identify interactions between scaffold proteins and trans-phosphorylation as an additional level of regulation in the ERK cascade, with broad implications in signaling and the design of scaffold protein-aimed therapeutics

La resonancia magnética cardíaca, pieza clave en el paciente con miocarditis aguda

Inflammation of the myocardium, viral or not, is called myocarditis. Diagnosis can be a real challenge, and appropriate differential diagnosis with other conditions is needed. Endomyocardial biopsy has been the classical gold standard for the diagnosis of this disease, but nowadays it has been largely replaced by cardiac MRI. A case of a patient with acute myocarditis is presented to emphasize the leading role of cardiac MRI as the first choice test for this kind of patients.La inflamación del miocardio, vírica o no, recibe el nombre de miocarditis. Este cuadro supone un reto para el médico clínico en su práctica habitual, ya que es fundamental realizar un diagnóstico diferencial correcto con otros cuadros que puede emular. La biopsia endomiocárdica ha sido clásicamente la técnica de referencia en el diagnóstico de esta entidad, aunque actualmente la cardio-RM es la técnica más empleada para valorar este tipo de pacientes. Se presenta un caso de un paciente con miocarditis aguda con el que se pretende enfatizar el papel protagonista de la cardio-RM como prueba de imagen de elección

Nanopartículas de CuO e sua propriedade antimicrobiana frente a cepas intrahospitalares

Empleando un prototipo de reactor, se sintetizaron nanopartículas (NPs) de CuO a través del método de precipitación a partir de CuSO2·5H2O y de Cu(CH3COO)2·H2O. Las NPs obtenidas fueron caracterizadas mediante XRD, FT-IR, TEM y SEM. La actividad antimicrobiana de las NPs se determinó mediante el método de difusión en placa, colocando 20 mg de NPs de CuO sobre cuatro cepas intrahospitalarias o nosocomiales aisladas de la Unidad de Cuidados Intensivos de un hospital nacional de Lima norte (Staphylococcus epidermidis, Aerococcus viridans, Ochrobactrum anthropi y Micrococcus lylae). La caracterización de las NPs de CuO demostró que las sintetizadas a partir de acetato (CuO–Acet) presentaron una fase pura de CuO, mientras que las sintetizadas a partir de sulfato (CuO–Sulf) presentaron dos fases, donde la de CuO representó más del 84%. Los dominios cristalinos del CuO–Acet y CuO–Sulf fueron 15 y 19 nm, respectivamente. Los halos de inhibición de las cepas estudiadas fueron mayores para las NPs de CuO–Sulf que para las NPs de CuO–Acet; solo para la cepa Ochrobactrum anthropi se presentaron halos similares para ambos tipos de NPsUsing a prototype reactor, CuO nanoparticles (NPs) were synthetized through the precipitation method, starting from CuSO2 .5H2O and Cu(CH3COO)2 .H2O. The obtained NPs were characterized by XDR, FT-IR, SEM, and TEM. The antimicrobial activity of the NPs was determined by the plate diffusion method, placmg 20 mg of NPs onto four nosocomial strains obtained from north Lima national hospital Intensive-Care Unit (Staphylococcus epideiwidis, Aerococcus viridans, Ochrobactrwn anthropic, and Micrococcus lylae). NPs characterization revealed that those synthetized from acetate (CuO-Acet) shown pure CuO phase, while those synthetized from sulphate CuO-Sulf shown two phases where CuO was the predominant one, having more than 84%. The crystal domains for CuO-Acet and CuO-Sulf were 15 and 19 nm, respectively. The inhibition halos for the studied strains were larger for CuO-Sulf NPs than CuO-Acet NPs, only Ochrobactrum anthropi displayed similar inhibition halos for both types of NPs.Facultad de Ciencias ExactasFacultad de Ingenierí

Nanopartículas de CuO e sua propriedade antimicrobiana frente a cepas intrahospitalares

Empleando un prototipo de reactor, se sintetizaron nanopartículas (NPs) de CuO a través del método de precipitación a partir de CuSO2·5H2O y de Cu(CH3COO)2·H2O. Las NPs obtenidas fueron caracterizadas mediante XRD, FT-IR, TEM y SEM. La actividad antimicrobiana de las NPs se determinó mediante el método de difusión en placa, colocando 20 mg de NPs de CuO sobre cuatro cepas intrahospitalarias o nosocomiales aisladas de la Unidad de Cuidados Intensivos de un hospital nacional de Lima norte (Staphylococcus epidermidis, Aerococcus viridans, Ochrobactrum anthropi y Micrococcus lylae). La caracterización de las NPs de CuO demostró que las sintetizadas a partir de acetato (CuO–Acet) presentaron una fase pura de CuO, mientras que las sintetizadas a partir de sulfato (CuO–Sulf) presentaron dos fases, donde la de CuO representó más del 84%. Los dominios cristalinos del CuO–Acet y CuO–Sulf fueron 15 y 19 nm, respectivamente. Los halos de inhibición de las cepas estudiadas fueron mayores para las NPs de CuO–Sulf que para las NPs de CuO–Acet; solo para la cepa Ochrobactrum anthropi se presentaron halos similares para ambos tipos de NPsUsing a prototype reactor, CuO nanoparticles (NPs) were synthetized through the precipitation method, starting from CuSO2 .5H2O and Cu(CH3COO)2 .H2O. The obtained NPs were characterized by XDR, FT-IR, SEM, and TEM. The antimicrobial activity of the NPs was determined by the plate diffusion method, placmg 20 mg of NPs onto four nosocomial strains obtained from north Lima national hospital Intensive-Care Unit (Staphylococcus epideiwidis, Aerococcus viridans, Ochrobactrwn anthropic, and Micrococcus lylae). NPs characterization revealed that those synthetized from acetate (CuO-Acet) shown pure CuO phase, while those synthetized from sulphate CuO-Sulf shown two phases where CuO was the predominant one, having more than 84%. The crystal domains for CuO-Acet and CuO-Sulf were 15 and 19 nm, respectively. The inhibition halos for the studied strains were larger for CuO-Sulf NPs than CuO-Acet NPs, only Ochrobactrum anthropi displayed similar inhibition halos for both types of NPs.Facultad de Ciencias ExactasFacultad de Ingenierí

Nanopartículas de CuO e sua propriedade antimicrobiana frente a cepas intrahospitalares

Empleando un prototipo de reactor, se sintetizaron nanopartículas (NPs) de CuO a través del método de precipitación a partir de CuSO2·5H2O y de Cu(CH3COO)2·H2O. Las NPs obtenidas fueron caracterizadas mediante XRD, FT-IR, TEM y SEM. La actividad antimicrobiana de las NPs se determinó mediante el método de difusión en placa, colocando 20 mg de NPs de CuO sobre cuatro cepas intrahospitalarias o nosocomiales aisladas de la Unidad de Cuidados Intensivos de un hospital nacional de Lima norte (Staphylococcus epidermidis, Aerococcus viridans, Ochrobactrum anthropi y Micrococcus lylae). La caracterización de las NPs de CuO demostró que las sintetizadas a partir de acetato (CuO–Acet) presentaron una fase pura de CuO, mientras que las sintetizadas a partir de sulfato (CuO–Sulf) presentaron dos fases, donde la de CuO representó más del 84%. Los dominios cristalinos del CuO–Acet y CuO–Sulf fueron 15 y 19 nm, respectivamente. Los halos de inhibición de las cepas estudiadas fueron mayores para las NPs de CuO–Sulf que para las NPs de CuO–Acet; solo para la cepa Ochrobactrum anthropi se presentaron halos similares para ambos tipos de NPsUsing a prototype reactor, CuO nanoparticles (NPs) were synthetized through the precipitation method, starting from CuSO2 .5H2O and Cu(CH3COO)2 .H2O. The obtained NPs were characterized by XDR, FT-IR, SEM, and TEM. The antimicrobial activity of the NPs was determined by the plate diffusion method, placmg 20 mg of NPs onto four nosocomial strains obtained from north Lima national hospital Intensive-Care Unit (Staphylococcus epideiwidis, Aerococcus viridans, Ochrobactrwn anthropic, and Micrococcus lylae). NPs characterization revealed that those synthetized from acetate (CuO-Acet) shown pure CuO phase, while those synthetized from sulphate CuO-Sulf shown two phases where CuO was the predominant one, having more than 84%. The crystal domains for CuO-Acet and CuO-Sulf were 15 and 19 nm, respectively. The inhibition halos for the studied strains were larger for CuO-Sulf NPs than CuO-Acet NPs, only Ochrobactrum anthropi displayed similar inhibition halos for both types of NPs.Facultad de Ciencias ExactasFacultad de Ingenierí