Engineering of silicon surfaces at the micro- and nanoscales for cell adhesion and migration control

The engineering of surface patterns is a powerful tool for analyzing cellular communication factors involved in the processes of adhesion, migration, and expansion, which can have a notable impact on therapeutic applications including tissue engineering. In this regard, the main objective of this research was to fabricate patterned and textured surfaces at micron- and nanoscale levels, respectively, with very different chemical and topographic characteristics to control cell–substrate interactions. For this task, one-dimensional (1-D) and two-dimensional (2-D) patterns combining silicon and nanostructured porous silicon were engineered by ion beam irradiation and subsequent electrochemical etch. The experimental results show that under the influence of chemical and morphological stimuli, human mesenchymal stem cells polarize and move directionally toward or away from the particular stimulus. Furthermore, a computational model was developed aiming at understanding cell behavior by reproducing the surface distribution and migration of human mesenchymal stem cells observed experimentally

Grafeno: Concepto y aplicaciones

El grafeno es un material novedoso que, aunque ya se teorizaba con él hace más de setenta años por las curiosas características que prometía tener, no se pudo aislar para su estudio y aplicación hasta principios de este siglo. Desde entonces, numerosos grupos científicos investigan, desde un punto de vista teórico y experimental, sus propiedades fisicoquímicas y las que pueden darse por la combinación consigo mismo y con otros materiales. Estos estudios (especialmente aquellos relacionados con su fabricación de alta calidad y en grandes láminas), han despertado el interés de la industria y han hecho que encontrar dispositivos o materiales basados en grafeno en nuestro día a día sea cada vez más común. Para comprender la razón por la cual este material es tan especial, es necesario entender primero qué es y cuáles son las propiedades fundamentales que le hacen tan prometedor en un sinfín de aplicaciones (de las cuales se comentarán algunas actuales y otras futuras). Por eso, el texto se ha estructurado procurando que el lector obtenga una introducción guiada que le permita no sólo comprender el material en sí, sino también aportarle los fundamentos y algunos ejemplos para buscar sus propias aplicaciones en su entorno más inmediato.Sin financiaciónNo data 2020UE

Plasma Fabrication and SERS Functionality of Gold Crowned Silicon Submicrometer Pillars

Sequential plasma processes combined with specific lithographic methods allow for the fabrication of advanced material structures. In the present work, we used self-assembled colloidal monolayers as lithographic structures for the conformation of ordered Si submicrometer pillars by reactive ion etching. We explored different discharge conditions to optimize the Si pillar geometry. Selected structures were further decorated with gold by conventional sputtering, prior to colloidal monolayer lift-off. The resulting structures consist of a gold crown, that is, a cylindrical coating on the edge of the Si pillar and a cavity on top. We analysed the Au structures in terms of electronic properties by using X-ray absorption spectroscopy (XAS) prior to and after post-processing with thermal annealing at 300 °C and/or interaction with a gold etchant solution (KI). The angular dependent analysis of the plasmonic properties was studied with Fourier transformed UV-vis measurements. Certain conditions were selected to perform a surface enhanced Raman spectroscopy (SERS) evaluation of these platforms with two model dyes, prior to confirming the potential interest for a well-resolved analysis of filtered blood plasma.Ministry of Science, Innovation and Universities of Spain - grant SPECTRASENSE (RTC-2017-6311-1)Spline (Spanish CRG beamline at the ESRF) (25-01/986)3.623 JCR (2020) Q2, 79/162 Chemistry, Physical0.682 SJR (2020) Q2, 180/638 Materials Science (miscellaneous)No data IDR 2020UE