Development of advanced and multifunctional biomaterials from two- or three-dimensional structures of cellulose

Programa de doctorat: Doctorat en Enginyeria Tèxtil i Paperer

Characterization of airborne particulate matter and its toxic and proarrhythmic effects: A case study in Aburrá Valley, Colombia

Particle matter (PM) is a complex mixture of particles suspended in the air, mainly caused by fuel combustion from vehicles and industry, and has been related to pulmonary and cardiovascular diseases. The Metropolitan Area of Aburrá Valley in Colombia is the second most populous urban agglomeration in the country and the third densest in the world, composed of ten municipalities. Examining the physicochemical properties of PM is crucial in comprehending its composition and its effects on human health, as it varies based on the socioeconomic dynamics specific to each city. This study characterized the PM collected from the north, south, and central zones to evaluate its chemical composition and morphology. Different elements such as silicon, carbon, aluminum, potassium, calcium, sodium, iron, magnesium, and copper and the presence of unburned fuel, motor oil, and silicon fibers were identified. In vitro and in silico studies were conducted to evaluate the toxicity of the PM, and it was found that the PM collected from the central zone had the greatest impact on cell viability and caused DNA damage. The in silico study demonstrated that PM has concentration-dependent proarrhythmic effects, reflected in an action potential duration shortening and an increased number of reentries, which may contribute to the development of cardiac arrhythmias. Overall, the results suggest that the size and chemical composition of ambient PM can induce toxicity and play an important role in the generation of arrhythmiasThis work was supported by the Ministerio de Ciencia Tecnología e Innovación (MINCIENCIAS) from Colombia, through grant No. 120677757994 and by the Dirección General de Política Científica de la Generalitat Valenciana PROMETEO/2020/043. The work of Palacio was supported by the “Programa de excelencia doctoral del Bicentenario 2019” of MINCIENCIAS. The work of Durango-Giraldo and Zapata-Hernandez was supported by the “Convocatoria para el fortalecimiento de proyectos en ejecución de CTeI en ciencias de la salud con talento joven e impacto regional” of MINCIENCIASPostprint (published version

Atrial proarrhythmic effect of lead as one of the PM10 metal components of air pollution. An in-silico study

[EN] Particulate matter (PM) is considered the most severe environmental pollution problem due to its serious effects on human health associated with an increased risk of cardiovascular morbidity and mortality. In this work, a physicochemical characterization of PM10 from the city of Medellin was developed. The results evince that lead (Pb) is one of the most abundant elements since it is present in all analyzed samples. Therefore, Pb was chosen to perform an in-silico study to assess its effects on atrial arrhythmias generation. For this purpose, we developed a model representing the Pb2+ blocking effect on the L-type calcium channel. This formulation was incorporated in a human atrial cell mathematical model and in 2D and 3D models of human atria. The simulations showed a proarrhythmic effect at high Pb2+ concentrations, through shortening of action potential duration inducing the generation of reentrant activity and atrial flutter. The results contribute to the knowledge about the cardiac physiopathological processes, triggered by lead as one of the main PM10 metal components of air pollution, that yields the generation of arrhythmias.This work was supported by Ministerio de Ciencia, Tecnologi a e Innovacion MINCIENCIAS from Colombia, through grant No. 120677757994; and by the Direccion General de Politica Cientifica de la Generalitat Valenciana PROMETEO/2020/043.Palacio, LC.; Pachajoa, DC.; Durango-Giraldo, G.; Zapata-Hernández, C.; Ugarte, JP.; Saiz Rodríguez, FJ.; Buitrago-Sierra, R.... (2021). Atrial proarrhythmic effect of lead as one of the PM10 metal components of air pollution. An in-silico study. PLoS ONE. 16(10):1-17. https://doi.org/10.1371/journal.pone.0258313S117161

Development and evaluation of the physicochemical and antibacterial properties of latex/zinc oxide compounds for applications in biomedical engineering

ilustracioneds, diagramasEl látex de caucho natural es un polímero extraído del árbol de caucho (Hevea brasiliensis). Es un material ecológico, sostenible, no derivado del petróleo y de bajo costo. Ha sido empleado en diferentes aplicaciones en el campo biomédico como la regeneración, prótesis e injertos óseos, además de su uso en guantes, catéteres, condones, entre otros. No obstante, no presenta propiedades antibacterianas, lo que podría llevar a una colonización bacteriana en la superficie del material. El óxido de Zinc (ZnO) es un material inorgánico que dentro de sus propiedades presenta actividad antibacteriana, que dependen de diversos factores, entre ellos su morfología. El ZnO puede ser empleado para la modificación del látex con el fin de otorgarle propiedades antibacterianas. Sin embargo, las propiedades antibacterianas de partículas de ZnO, embebidas en el látex no han sido ampliamente estudiadas. En este trabajo, se sinterizaron partículas de ZnO con dos diferentes morfologías y fueron añadidas al látex a diferentes concentraciones con el fin de evaluar las propiedades antibacterianas del compuesto. Los resultados de caracterización por SEM y TEM mostraron la obtención de partículas con morfología esférica y de hojas. Por medio de DRX, se concluyó que ambos tipos de partícula presentan fase cristalina Wurtzita, la más comúnmente encontrada en el ZnO. Mediante EDS se evidenció presencia de las partículas de ZnO por la superficie del compuesto, sin embargo, para la morfología de hojas, se obtuvo una menor exposición en la superficie del compuesto y se pudieron observar agregados de partículas. Con respecto a las pruebas antibacterianas, se encontró que ambos compuestos presentan esta propiedad contra bacterianas Gram negativas y Gram positivas, sin embargo, se evidenció una mayor efectividad antibacteriana en las partículas con morfología esférica. La cual se asoció a la mayor exposición de las partículas de ZnO en la superficie de estos compuestos, en comparación con los desarrollados con morfología de hojas. (Texto tomado de la fuente)Natural rubber latex is a polymer extracted from the rubber tree (Hevea brasiliensis). It is an ecological, sustainable material, not derived from petroleum and low cost. It has been used in several applications in the biomedical field such as regeneration, prosthetics and bone grafts, in addition to its use in gloves, catheters, condoms, among others. However, it does not have antibacterial properties, which could lead to bacterial colonization on the surface of the material. Zinc oxide (ZnO) is an inorganic material that has antibacterial activity within its properties, which depend on various factors, including its morphology. ZnO can be used to modify latex in order to give it antibacterial properties. Nevertheless, the antibacterial properties of ZnO, embedded in the latex, have not been widely studied. In this work, ZnO particles with two several morphologies were synthesized and added to latex at different concentrations in order to evaluate the antibacterial properties of this compound. The results of characterization by SEM and TEM showed the obtaining of particles with spherical morphology and sheets. Through XRD, it was concluded that both types of particles present Wurtzite crystalline phase, the most commonly found in ZnO. EDS analysis evidenced the presence of ZnO particles on the surface of the compound, however, the morphology of sheets exhibits a lower exposure on the surface of the compound and aggregates of particles could be observed. Regarding the antibacterial tests, it was found that both compounds have this property against Gram-negative and Gram-positive bacteria, however, a greater antibacterial effectiveness was evidenced in the particles with spherical morphology. This relates to greater exposure of ZnO particles on the surface of these compounds, compared to those developed with sheets morphology.MaestríaMagíster en Ingeniería - Materiales y ProcesosNuevos materialesÁrea Curricular de Materiales y Nanotecnologí

Breve estado del arte de la celulosa bacteriana y sus aplicaciones

La celulosa es un biopolímero, el cual constituye la pared celular de las plantas, junto con la lignina y la hemicelulosa. La celulosa también puede ser producida por microorganismo, tales como bacterias. Esta celulosa, conocida comúnmente como celulosa bacteriana (BC por sus siglas en inglés), se produce por la fermentación del medio en el que se encuentren las bacterias. Este material, presenta propiedades fisicoquímicas importantes que lo hacen promisorio para diversas aplicaciones en diversos ámbitos como lo son la industria biomédica, industria alimentaria, tratamiento de aguas residuales, biocompuestos, entre otros. En la superficie de la celulosa bacteriana abundan los grupos hidroxilo, lo cual facilita su modificación con diferentes materiales u otros grupos funcionales, con el fin de ampliar su uso en diferentes campos de aplicación. En este trabajo, se mostrarán brevemente, los factores que influyen en la producción de celulosa bacteriana, como puede ser modificada con diferentes materiales y los resultados de algunas investigaciones, donde ha sido utilizada la celulosa bacteriana para diferentes aplicacione