Actin cytoskeletal organization in human osteoblasts grown on different dental titanium implant surfaces

The understanding of the cellular basis of osteoblastic cell-biomaterial interaction is crucial to the analysis of the mechanism of osseointegration. Cell adhesion is a complex process that is dependent on the cell types and on the surface microtopography and chemistry of the substrate. We have studied the role of microtopography in modulating cell adhesion, in vitro, using a human osteoblastic cell line for the assessment of actin cytoskeletal organization. Through application of CLSM combining reflection and fluorescence, 2D or 3D images of cytoskeleton were obtained. On smooth surfaces, Ti CP machined, predominantly planar bone cells with an axial ratio of 1.1 were randomly oriented, with stress fibers running in all directions, and thin filopodia. On T iCP Osseotite ® surfaces the osteoblastic cells conformed to the irregular terrain of the sustrate with focal adhesion sites only established on the relative topographical peaks separated for a longer distance than in the machined surface, and defined wide lamellopodia and long filopodia, with enhanced expression of stress fibers, forming large clear focal contacts with the rough surface. The cytoskeletal organization of cells cultured on rough titanium supports an active role for the biomaterial surface in the events that govern osteoblastic cell adhesion. The results enforce the role of the rough sustrate surface in affecting osteoblastic cell adhesion and provide valuable information for the design of material surfaces that are required for the development of an appropriate osteogenic surface for osteoblastic anchorage, compared to machined surface, in dental implants

Mitochondrial bioenergetics and distribution in living human osteoblasts grown on implant surfaces

Osseointegration of implants is crucial for the long-term success of oral implants. The periimplant bone formation by osteoblasts is strongly dependent on the local mechanical environment in the interface zone. Robust demands for energy are placed on osteoblasts during the adhesion process to solid surfaces, and mitochondria are capital organelles in the production of most of the ATP needed for the process. We have assessed the relationship between osteoblast differentiation and mitochondrial bioenergetics in living cells grown on two different titanium surfaces, in order to provide valuable information for the design of material surfaces required for the development of the most appropriate osteogenic surface for osteoblastic anchorage. Combined backscattered and fluorescence confocal microscopy showed that in flat cells grown on a machined surface, highly energized mitochondria were distributed along the cell body. In contrast, cells grown on the rough surface emitted long protrusions in search of surface roughness, with actin stress fibers clearly polarized and highly energized mitochondria clustered at focal adhesion sites. This report using normal human osteoblastic cells indicates that these cells are especially sensitive to surface cues through energy production that enhances the necessary adhesion required for a successful osseointegration

Membrana reabsorbible para regeneración ósea guiada

Membrana reabsorbible para regeneración ósea guiada. La invención se refiere a membranas para la regeneración ósea guiada, que comprenden un polímero biodegradable que ha sido tratado en una de sus caras con un plasma, y sobre el que se ha depositado una o más capas nanométricas de óxidos activos en una o en las dos caras. La invención se refiere también a los usos y métodos de obtención de dichas membranas y a implantes basados en las mismas.Españ

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Estudios superiores en Cádiz desde 1748. Armada e ilustración

Este libro parte de la idea de recuperar el origen de los estudios universitarios en Cádiz, así como de poner de relieve la importancia de la colaboración institucional, acercando, como en el siglo XVIII, la Armada, la Ciencia y la Sociedad.243 págs