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

Biotic, abiotic, and anthropogenic drivers of demographic performance of non-native Eucalyptus and Pinus species in forested areas of Spain

Non-native trees enhance services that are fundamental for human well-being. Yet, the extensive use of non-native trees has the potential of causing environmental and socio-economic harm. Eucalyptus and Pinus are the most widely distributed and extensively planted tree genera worldwide, because their rapid growth allows profitable production of timber and pulp. Their naturalization is causing severe effects on the environment, but the relative importance of underlying factors determining their demographic performance is not well known. Thus, our aim was to evaluate the relative importance of biotic, abiotic, and anthropogenic factors driving demographic changes of Eucalyptus and Pinus at the regional scale. We compiled environmental variables and demographic data for Eucalyptus globulus, Eucalyptus camaldulensis, and Pinus radiata across 6388 permanent forestland plots surveyed in the Spanish Forest Inventory (SFI). We used the second (1986?1996), third (1997?2007), and fourth (2008?2017) SFI datasets to quantify annual changes in basal area per plot between consecutive inventories (?BA; m2 ha?1 year?1). We also quantified the components of ?BA: tree ingrowth (transitions from juvenile to adult trees), growth, and mortality. We evaluated juvenile recruitment with in-situ regeneration (No. juvenile trees ha?1) within plots already occupied by the focal species in the previous inventory, and with natural colonization of plots where the focal species was absent at the beginning of the time interval. We found that the structure of the biotic community was especially important to explain demographic performance of non-native trees growing in benign environments (E. globulus and P. radiata), whereas abiotic factors were particularly important regulating basal area increments of E. camaldulensis, which occurs in harsher environments. Basal area increments decreased with species and functional richness, heterospecific density, mean annual temperature, and increased with soil capacity to retain nutrients and water. Colonization of new plots increased with propagule availability in the surrounding landscape. Tree cutting was beneficial for P. radiata. Collectively, our results suggest that non-native trees perform better in forests with high propagule pressure, low biotic resistance, favourable abiotic conditions, and human management.Agencia Estatal de InvestigaciónUniversidad de AlcaláMinisterio de Ciencia e InnovaciónComunidad de Madri

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

Diabetes insípida perioperatoria secundaria a litio.: Reporte de un caso

Diabetes insipidus is a pathology characterized by the elimination of large amounts of dilute urine. The antidiuretic hormone is responsible of water reabsorption in medullary collecting duct in the kidney. There are two main types of diabetes insipidus, on one hand the neurogenic or central diabetes insipidus and on the other hand the nephrogenic or secondary diabetes insipidus, depending on the level that is affected. Several drugs have been related to loss of renal concentrating mechanism, being the lithium one of them. We present a case report of a patient undergoing surgery for benign pyloric stenosis in pharmacological long-term maintenance treatment of bipolar disorder with lithium. During the intraoperative period the patient began with high urine output and diabetes insipidus was suspected.La diabetes insípida es una patología caracterizada por la eliminación de volúmenes muy elevados de orina diluida. La hormona antidiurética es la encargada de regular la reabsorción de agua en el túbulo colector.  Podemos diferenciar dos variantes, la neurogénica o central y la nefrogénica o secundaria según el nivel que esté afectado. Varios fármacos han sido relacionados con la pérdida de la capacidad concentradora renal de la orina, siendo el litio uno de ellos. Presentamos el caso de una paciente sometida a intervención quirúrgica por estenosis benigna de píloro en tratamiento farmacológico con litio por trastorno bipolar que durante el periodo intraoperatorio comenzó con diuresis elevada sospechándose diabetes insípida

Rediseño, puesta en marcha y análisis de un banco de ensayos de intercambiadores de calor entre materiales de cambio de fase (PCM)-agua.

El presente TFG se desarrolla en el marco del trabajo de investigación del grupo GITSE, perteneciente al Instituto Universitario de Investigación en Ingeniería de Aragón (I3A), y los resultados forman parte del proyecto TRIGENSOL (proyecto de I+D+i PID2020-115500RB-I00), financiado por MCIN/ AEI/10.13039/501100011033. Consiste en estudiar el comportamiento de las emulsiones de materiales de cambio de fase con pequeños tamaños de partícula, del orden de las micras (mPCM), como fluido caloportador. Este TFG es continuación de los trabajos previos realizados por los estudiantes Guillermo Sanz y Jorge Torrubia. El trabajo de investigación quedó paralizado por la pandemia de la Covid-19 y el objetivo general de este TFG es retomar la investigación que quedó aparcada hace dos años, empezando por rediseñar la instalación experimental donde se pueda ensayar el intercambio de calor experimentado entre una emulsión de materiales de cambio de fase (PCM) y agua en distintos modos de operación que se organizan en diferentes circuitos, como se explica más adelante en la presente memoria. El objetivo general que se persigue es dejar la instalación rediseñada, montada y validada con una sustancia de propiedades bien conocidas, como el agua, y dejarla totalmente preparada para, en el futuro, poder ensayar con distintas emulsiones de mPCM que se consideren de interés. Un elemento de especial relevancia del trabajo es comprobar el comportamiento de una estructura tan compacta como son los intercambiadores de calor de placas corrugadas. Por ello se ha hecho un esfuerzo particular en el estudio teórico de su comportamiento, para cotejarlo con los ensayos que se han realizado en la instalación.<br /

Gene expression profiling in human neutrophils after infection with Acinetobacter baumannii in vitro

Acinetobacter baumannii is a Gram negative nosocomial pathogen that has acquired increasing worldwide notoriety due to its high antibiotic resistance range and mortality rates in hospitalized patients. Therefore, it is necessary to better understand key aspects of A. baumannii pathogenesis such as host-pathogen interactions. In this report, we analyzed both gene expression and cytokine production by human neutrophils infected with A. baumannii. Our assays reveal a proinflammatory response of neutrophils after A. baumannii infection, since intracellular transcription of effector proteins such as COX-2, transcription factors, and proinflammatory cytokines resulted significantly upregulated in neutrophils infected by A. baumannii, compared with unstimulated human neutrophils. Translation and release of CXCL-8, IL-1? and TNF-? by neutrophils was confirmed by protein quantification in culture supernatants. Results obtained in this report reinforce the importance of human neutrophils in controlling A. baumannii infections but also emphasize the proinflammatory nature of these host-pathogen interactions as a target for future immunomodulatory therapies

Acinetobacter Baumannii Maintains Its Virulence After Long-Time Starvation

Acinetobacter baumannii is a cause of healthcare-associated infections. Although A. baumannii is an opportunistic pathogen, its infections are notoriously difficult to treat due to intrinsic and acquired antimicrobial resistance, often limiting effective therapeutic options. A. baumannii can survive for long periods in the hospital environment, particularly on inanimate surfaces. Such environments may act as a reservoir for cross-colonization and infection outbreaks and should be considered a substantial factor in infection control practices. Moreover, clothing of healthcare personnel and gadgets may play a role in the spread of nosocomial bacteria. A link between contamination of hospital surfaces and A. baumannii infections or between its persistence in the environment and its virulence has not yet been established. Bacteria under stress (i.e., long-term desiccation in hospital setting) could conserve factors that favor infection. To investigate whether desiccation and/or starvation may be involved in the ability of certain strains of A. baumannii to retain virulence factors, we have studied five well-characterized clinical isolates of A. baumannii for which survival times were determined under simulated hospital conditions. Despite a considerable reduction in the culturability over time (up to 88% depending on strain and the condition tested), some A. baumannii strains were able to maintain their ability to form biofilms after rehydration, addition of nutrients, and changing temperature. Also, after long-term desiccation, several clinical strains were able to grow in the presence of non-immune human serum as fine as their non-stressed homologs. Furthermore, we also show that the ability of bacterial strains to kill Galleria mellonella larvae does not change although A. baumannii cells were stressed by long-term starvation (up to 60 days). This means that A. baumannii can undergo a rapid adaptation to both the temperature shift and nutrients availability, conditions that can be easily found by bacteria in a new patient in the hospital setting.Research in our laboratory is supported by the Spanish Instituto de Salud Carlos III, Spain (grant PI16/01103 to José Ramos-Vivas) and the Plan Nacional de I+D+i 2008-2011 and Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Economía y Competitividad, Spanish Network for Research in Infectious Diseases (REIPI RD12/0015) - co-financed by European Development Regional Fund "A way to achieve Europe" ERDF. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Whole-genome sequence of Acinetobacter pittii HUMV-6483 isolated from human urine

Acinetobacter pittii strain HUMV-6483 was obtained from urine from an adult patient. We report here its complete genome assembly using PacBio singlemolecule real-time sequencing, which resulted in a chromosome with 4.07 Mb and a circular contig of 112 kb. About 3,953 protein-coding genes are predicted from this assembly