36 research outputs found

    Dual sensing-actuation artificial muscle based on polypyrrole-carbon nanotube composite

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    Dual sensing artificial muscles based on conducting polymer are faradaic motors driven by electrochemical reactions, which announce the development of proprioceptive devices. The applicability of different composites has been investigated with the aim to improve the performance. Addition of carbon nanotubes may reduce irreversible reactions. We present the testing of a dual sensing artificial muscle based on a conducting polymer and carbon nanotubes composite. Large bending motions (up to 127 degrees) in aqueous solution and simultaneously sensing abilities of the operation conditions are recorded. The sensing and actuation equations are derived for incorporation into a control system.The research was supported by European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 641822

    Properties of polypyrrole polyvinilsulfate films for dual actuator sensing systems

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    One of the challenges of modern science is the development of actuators able to sense working conditions while actuation, mimicking the way in which biological organs work. Actuation of those organs includes nervous (electric) pulses dense reactive gels, chemical reactions exchange of ions and solvent. For that purpose, conducting polymers are being widely studied. In this work the properties of self-supported films of the polypyrrole:polyvinilsulfate (PPy/PVS) blend polymer were assessed. X-ray photoelectron spectroscopy (XPS) studies show how during reduction / oxidation the polymer exchanges cations when immersed in a NaClO4 aqueous solution, revealing free positive charges in the electrolytic solution as the driving agents leading to the swelling/shrinking of the polymer. Eventually it is the phenomenon responsible of the actuation of the polymeric motors. Submitting the system to consecutive potential sweeps shows the reaction is really sensing the scan rate used in each cycle revealing that while actuating the system is actually sensing the electrochemical working conditions.The research was supported by European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 641822

    Tetraspanins interweave EV secretion, endosomal network dynamics and cellular metabolism

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    Tetraspanin proteins organize membrane nanodomains related to cell adhesion and migration. An essential feature conserved along the superfamily is their cone-shaped tertiary structure, which allows tetraspanins to be enriched in highly curved membrane structures. Their conical shape, together with their ability to associate to transmembrane receptors and to bind to cystoskeletal and signaling scaffolds, are key in their ability to regulate endosomal network dynamics and Extracellular Vesicle biogenesis and cargo selection. Recent evidence suggests that tetraspanins have a relevant impact in mitochondria turnover and regulation of cellular metabolism. In this review we highlight those reports that point to tetraspanins as key regulators in the communication between the endosomal network, EVs and the cellular metabolismWe thank Dr. Cabañas for critical reading of the manuscript. This work has been supported by grants BIO2017-86500-R, PID2020- 119627GB-I00, and RED2018-102411-T TeNTaCLES from Ministerio Español de Ciencia e Innovación (Spain) to MY-M. VT is supported by an FPI-UAM predoctoral fellowshi

    Self-supported polypyrrole/polyvinylsulfate films: electrochemical synthesis, characterization, and sensing properties of their redox reactions

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    Thick films of polypyrrole/polyvinylsulfate (PPy/PVS) blends were electrogenerated on stainless‐steel electrodes under potentiostatic conditions from aqueous solution. The best electropolymerization potential window was determined by cyclic voltammetry. After removing the film from the back metal, self‐supported electrodes were obtained. Voltammetric, coulovoltammetric, and chronoamperometric responses from a LiClO4 aqueous solution indicated the formation of an energetically stable structure beyond a reduction threshold of the material. Its subsequent oxidation required higher anodic voltammetric overpotentials or longer chronoamperometric oxidation times. This structure was attributed to the formation of lamellar or vacuolar structures. X‐ray photoelectron spectroscopy analysis of the films under different oxidations states revealed that the electrochemical reactions drive the reversible exchange of cations between the film and the electrolyte. The electrical energy and the charge consumed by the reversible reaction of the film under voltammetric conditions between the constant potential limits are a function of the potential scan rate, that is, they sense the working electrochemical conditions.This project was supported by the Marie‐Sklodowska‐Curie Innovative Training Network MICACT‐H2020‐MSCA‐ITN‐2014 and by the Séneca Foundation project 19253/PI/14

    Biomimetic reactions in conducting polymers for artificial muscles: sensing working conditions

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    IIn the dense gel that is the intracellular matrix forming part of living cells electrochemical reactions take place provoking the interchange of ions and water with the surroundings. Systems containing conducting polymers mimic this feature of biological organs. In particular, conducting polymers are being studied as dual sensing-actuating reactive materials giving new multifunctional sensing-actuators, which allow the construction and theoretical description of artificial proprioceptive devices. Here films of polypyrrole/dodecyl benzene sulfonate (PPy-DBS) coating a platinum electrode were submitted to potential sweeps at different sweep rates in order to explore if the polymer reaction senses the working electrochemical conditions. The effective consumed electrical energy per cycle follows a fast decrease when the scan rate increases described by the addition of two exponential sensing functions. Moreover, the variation of the hysteresis from the parallel charge/potential loop with the scan rate is also described by the addition of two exponential functions. In both cases the exponential functions fitting results at low scan rates are related to reaction-driven conformational movements of the polymer chains, being closer to biochemical conformational and allosteric sensors. The second exponential functions fitting results at high scan rates are related to diffusion kinetic control, being closer to present electrochemical sensors.The research was supported by European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 641822

    Embryonic trophectoderm secretomics reveals chemotactic migration and intercellular communication of endometrial and circulating MSCs in embryonic implantation

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    Embryonic implantation is a key step in the establishment of pregnancy. In the present work, we have carried out an in-depth proteomic analysis of the secretome (extracellular vesicles and soluble proteins) of two bovine blastocysts embryonic trophectoderm primary cultures (BBT), confirming different epithelial–mesenchymal transition stages in these cells. BBT-secretomes contain early pregnancy-related proteins and angiogenic proteins both as cargo in EVs and the soluble fraction. We have demonstrated the functional transfer of protein-containing secretome between embryonic trophectoderm and maternal MSC in vitro using two BBT primary cultures eight endometrial MSC (eMSC) and five peripheral blood MSC (pbMSC) lines. We observed that eMSC and pbMSC chemotax to both the soluble fraction and EVs of the BBT secretome. In addition, in a complementary direction, we found that the pattern of expression of implantation proteins in BBT-EVs changes depending on: (i) their epithelial–mesenchymal phenotype; (ii) as a result of the uptake of eMSC-or pbMSC-EV previously stimulated or not with embryonic signals (IFN-τ); (iii) because of the stimulation with the endometrial cytokines present in the uterine fluid in the peri-implantation perio

    La investigación biomédica en España (II). Evaluación del Fondo de Investigación Sanitaria (FIS) a través de los proyectos de investigación financiados en el período 1988-1995 a centros de investigación, facultades y escuelas

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    En un trabajo previo, publicado en esta misma revista, los autores han estudiado los resultados generados por los proyectos de investigación financiados por el Fondo de Investigación Sanitaria (FIS) a las Instituciones Sanitarias Asistenciales (hospitales) y los procedentes de los cuestionarios de encuestas remitidos a los investigadores responsables de tales proyectos y a los directores gerentes de los hospitales en los que se realizaron los mismos. En el presente trabajo, se continúa el proceso de evaluación del FIS, centrándose la atención en la distribución de los proyectos de investigación concedidos a los centros de investigación, facultades y escuelas, y en los resultados obtenidos a través de los cuestionarios de encuesta cumplimentados por los investigadores principales pertenecientes a estas instituciones o entidades.La realización de este trabajo ha sido posible gracias a la financiación otorgada por el FIS al proyecto de investigación 96/1803.Peer reviewe

    ALCAM/CD166 is involved in the binding and uptake of cancer-derived extracellular vesicles

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    Colorectal cancer (CRC) and ovarian cancer (OvC) patients frequently develop peritoneal metastasis, a condition associated with a very poor prognosis. In these cancers, tumor-derived extracellular vesicles (EVs) cause immunosuppression, facilitate the direct attachment and invasion of cancer cells through the mesothelium, induce the conversion of peritoneal mesothelial cells (PMCs) into cancer-associated fibroblasts (CAFs) and transfer a more aggressive phenotype amongst cancer cells. Although the promoting role of EVs in CRC and OvC peritoneal metastasis is well established, the specific molecules that mediate the interactions between tumor-derived EVs and immune and non-immune target cells remain elusive. Here, we employed the SKOV-3 (ovarian adenocarcinoma) and Colo-320 (colorectal adenocarcinoma) human cell lines as model systems to study the interactions and uptake of EVs produced by ovarian carcinoma and colorectal carcinoma cells, respectively. We established that the adhesion molecule ALCAM/CD166 is involved in the interaction of cancerderived EVs with recipient cancer cells (a process termed “EV binding” or “EV docking”) and in their subsequent uptake by these cells. The identification of ALCAM/CD166 as a molecule mediating the docking and uptake of CRC and OvC-derived EVs may be potentially exploited to block the peritoneal metastasis cascade promoted by EVs in CRC and OvC patient

    CD9 controls integrin α5β1-mediated cell adhesion by modulating its association with the metalloproteinase ADAM17

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    Integrin α5β1 is a crucial adhesion molecule that mediates the adherence of many cell types to the extracellular matrix through recognition of its classic ligand fibronectin as well as to other cells through binding to an alternative counter-receptor, the metalloproteinase ADAM17/TACE. Interactions between integrin α5β1 and ADAM17 may take place both in trans (between molecules expressed on different cells) or in cis (between molecules expressed on the same cell) configurations. It has been recently reported that the cis association between α5β1 and ADAM17 keeps both molecules inactive, whereas their dissociation results in activation of their adhesive and metalloproteinase activities. Here we show that the tetraspanin CD9 negatively regulates integrin α5β1-mediated cell adhesion by enhancing the cis interaction of this integrin with ADAM17 on the cell surface. Additionally we show that, similarly to CD9, the monoclonal antibody 2A10 directed to the disintegrin domain of ADAM17 specifically inhibits integrin α5β1-mediated cell adhesion to its ligands fibronectin and ADAM17.This work has been supported by the grant SAF2016-77096-R from Ministerio Español de Economía y Competitividad (MINECO) awarded to CC, by a grant from Fundación Ramón Areces Ayudas a la Investigación en Ciencias de la Vida y de la Materia, 2014 awarded to MY-M, and by the Deutsche Forschungsgemeinschaft (SFB 877, A6, Z3 and SPP1710) to JG and I

    Parasitismo intestinal en población de 1 a 10 años

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    Introduction: diseases caused by intestinal parasites are a serious health problem in children. Objective: to characterize the intestinal parasitism in the population between one and ten years of the community attended by the medical clinic No. 2 of the Pedro Borras Astorga Polyclinic, during the year 2017. Method: an observational, descriptive and transversal study was carried out. The universe consisted of 123 children, selecting a sample of 57. A bibliographic review of materials and sources was made on the different aspects treated in the research and the documentary analysis of the individual clinical histories; In addition, a data collection form was prepared, based on the medical interview. All variables were given an absolute and relative percentage frequency distribution. Results: male sex prevailed (54,4 %) and the age group between six and ten years old (51,2 %). Giardia lamblia was the main intestinal parasite (43,9 %). Abdominal pain was the main clinical manifestation (49,1 %). 70,2 % of the patients were normal weight. 38,6 % washed their hands before eating and 43,9 % after defecating. 42,1 % washed the food before ingesting it. 71,9 % drink treated water. The treatment of choice was effective in 61,4 % of the patients. Conclusions:the actions of prevention of health by the basic work team contribute to diminish the incidence of intestinal parasitism in the infantile population.Introducción: las enfermedades producidas por parásitos intestinales constituyen un grave problema de salud en la población infantil.Objetivo: caracterizar el parasitismo intestinal en la población entre uno y diez años de la comunidad atendida por el consultorio médico No. 2 del Policlínico Pedro Borras Astorga, durante el año 2017.Método: se realizó un estudio observacional, descriptivo y transversal. El universo estuvo constituido por 123 niños, seleccionándose una muestra de 57. Se realizó una revisión bibliográfica de materiales y fuentes sobre los diferentes aspectos tratados en la investigación y el análisis documental de las historias clínicas individuales; además se confeccionó una planilla de recolección de datos, a partir de la entrevista médica. A todas las variables se les realizó distribución de frecuencias absoluta y relativa porcentual.Resultados: predominó el sexo masculino (54,4 %) y el grupo de edad entre seis y diez años (51,2 %). La giardia lamblia constituyó el principal parásito intestinal (43,9 %). El dolor abdominal fue la principal manifestación clínica (49,1 %). El 70,2 % de los pacientes eran normopeso. El 38,6 % se lavaban las manos antes de ingerir alimentos y el 43,9 % después de defecar. El 42,1 % lavaban los alimentos antes de ingerirlos. El 71,9 % beben agua tratada. En el 61,4 % de los pacientes fue efectivo el tratamiento de elección.Conclusiones: las acciones de prevención de salud por parte del equipo básico de trabajo contribuyen a disminuir la incidencia del parasitismo intestinal en la población infanti
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