La ficción narrativa desde la técnica

La literatura en general es un acto de a dos: el autor propone y el lector completa la historia. Un libro tiene tantas lecturas como lectores. Y, a veces, más. Muchos de nosotros hemos leído un libro dos o tres veces, y nunca lo leemos de la misma manera. Porque en cada lectura intervienen muchos factores, especialmente el momento que estamos transitando. Como autores debemos abstenernos de contarlo todo, y dejar huecos para que el lector complete. Pero hay que conocer la técnica para ver qué se debe contar y qué no.Facultad de Ingenierí

Effects of graphene oxide nanoparticles on the immune system biomarkers produced by RAW264.7 and human whole blood cell cultures

Graphene oxide nanoparticles (GONPs) have attracted a lot of attention due to their many applications. These applications include batteries, super capacitors, drug delivery and biosensing. However, few studies have investigated the effects of these nanoparticles on the immune system. In this study, the in vitro effects of GONPs on the immune system was evaluated by exposing murine macrophages, RAW 264.7 cells and human whole blood cell cultures (to GONPs. The effects of GONPs on RAW cells were monitored under basal conditions. The whole blood cell cultures were exposed to GONPs in the presence or absence of the mitogens lipopolysaccharide (LPS) and phytohaemmagglutinin (PHA). A number of parameters were monitored for both RAWand whole blood cell cultures, these included cytotoxicity, inflammatory biomarkers, cytokines of the acquired immune system and a proteome profile analysis. The GONPs were cytotoxic to both RAW and whole blood cell cultures at 500 g/mL. In the absence of LPS, GONPs elicited an inflammatory response from the murine macrophage, RAW and whole blood cell cultures at 15.6 and 5 g/mL respectively. This activation was further corroborated by proteome profile analysis of both experimental cultures. GONPs inhibited LPS induced interleukin 6 (IL-6) synthesis and PHA induced interferon gamma (IFN ) synthesis by whole blood cell cultures in a dose dependent manner. In the absence of mitogens, GONPs stimulated IL-10 synthesis by whole blood cell cultures. The current study shows that GONPs modulate immune system biomarkers and that these may pose a health risk to individuals exposed to this type of nanoparticle

The stability and anti-angiogenic properties of titanium dioxide nanoparticles (tio2nps) using caco-2 cells

Titanium dioxide nanoparticles (TiO2NPs) are found in a wide range of products such as sunscreen, paints, toothpaste and cosmetics due to their white pigment and high refractive index. These wide-ranging applications could result in direct or indirect exposure of these NPs to humans and the environment. Accordingly, conflicting levels of toxicity has been associated with these NPs. Therefore, the risk associated with these reports and for TiO2NPs produced using varying methodologies should be measured. This study aimed to investigate the effects of various media on TiO2NP properties (hydrodynamic size and zeta potential) and the effects of TiO2NP exposure on human colorectal adenocarcinoma (Caco-2) epithelial cell viability, inflammatory and cell stress biomarkers and angiogenesis proteome profiles

The effects of carbon dots on immune system biomarkers, using the Murine Macrophage cell line RAW 264.7 and human whole blood cell cultures

Abstract: Carbon dots (CDs) are engineered nanoparticles that are used in a number of bioapplications such as bioimaging, drug delivery and theranostics. The effects of CDs on the immune system have not been evaluated. The effects of CDs on the immune system were assessed by using RAW264.7 cells and whole blood cell cultures. RAW cells were exposed to CD concentrations under basal conditions. Whole blood cell cultures were exposed to CD concentrations under basal conditions or in the presence of the mitogens, lipopolysaccharide (LPS) or phytohaemmagglutinin (PHA). After exposure, a number of parameters were assessed, such as cell viability, biomarkers of inflammation, cytokine biomarkers of the acquired immune system and a proteome profile analysis. CDs were cytotoxic to RAW and whole blood cell cultures at 62.5, 250 and 500 µg/mL, respectively. Biomarkers associated with inflammation were induced by CD concentrations ≥250 and 500 µg/mL under basal conditions for both RAW and whole blood cell cultures, respectively. The humoral immune cytokine interleukin (IL)-10 was increased at 500 µg/mL CD under both basal and PHA activated whole blood cell culture conditions. Proteome analysis supported the inflammatory data as upregulated proteins identified are associated with inflammation. The upregulated proteins provide potential biomarkers of risk that can be assessed upon CD exposure

Alumoxane/ferroxane nanoparticles for the removal of viral pathogens: the importance of surface functionality to nanoparticle activity

A bi-functional nano-composite coating has been created on a porous Nomex fabric support as a trap for aspirated virus contaminated water. Nomex fabric was successively dip-coated in solutions containing cysteic acid functionalized alumina (alumoxane) nanoparticles and cysteic acid functionalized iron oxide (ferroxane) nanoparticles to form a nanoparticle coated Nomex (NPN) fabric. From SEM and EDX the nanoparticle coating of the Nomex fibers is uniform, continuous, and conformal. The NPN was used as a filter for aspirated bacteriophage MS2 viruses using end-on filtration. All measurements were repeated to give statistical reliability. The NPN fabrics show a large decrease as compared to Nomex alone or alumoxane coated Nomex . An increase in the ferroxane content results in an equivalent increase in virus retention. This suggests that it is the ferroxane that has an active role in deactivating and/or binding the virus. Heating the NPN to 160 C results in the loss of cysteic acid functional groups (without loss of the iron nanoparticleﾒs core structure) and the resulting fabric behaves similar to that of untreated Nomex , showing that the surface functionalization of the nanoparticles is vital for the surface collapse of aspirated water droplets and the absorption and immobilization of the MS2 viruses. Thus, for virus immobilization, it is not sufficient to have iron oxide nanoparticles per se, but the surface functionality of a nanoparticle is vitally important in ensuring efficacy

Development of nanostructured membranes for environmental applications

Two new methods for the fabrication of porous membranes were studied. Ceramic membranes were obtained from alumoxane and ferroxane nanoparticles casted onto porous support materials. The synthesis of ferroxane nanoparticles was further investigated, in particular the kinetics of the reaction and the structure of the materials obtained by particle size measurements and EXAFS. The ceramics were characterized by nitrogen absorption isotherms, scanning electron microscope, and atomic force microscope. The permeability and molecular weight cut off (MWCO) of the ferroxane derived membranes were measured. These membranes have an average pore size of 24 run and a MWCO of 180,000 Daltons, which corresponds to the ultrafiltration range. The ferroxane nanoparticles were reacted with compounds containing other metallic atoms and mixed metal oxide nanoparticles were obtained. The nanoparticles can be applied to the fabrication of mixed metal oxide ceramics used in catalysis, fuel cells and other applications. The conductivity and surface acidity were determined in order to evaluate these materials as possible proton exchange membranes for fuel cells. The second fabrication method considered in this study is the template-derived process. Deposits of silica nanoparticles of variable morphology were prepared to be used as templates for porous membranes. The variables that control the morphology of the deposits were investigated, in particular those related to the solvent chemistry of the nanoparticle suspensions. The templates were obtained by self-assembly and Langmuir-Blodgett layer-by-layer deposition. By controlling the template deposition process, the self-assembly method was used to create dendritic templates with an asymmetric structure. The Langmuir-Blodgett technique was used to create bilayers of different pore size. Polystyrene membranes were fabricated as replicas of these template structures. The pore structure of the polymeric membranes was studied by scanning electron microscopy

Influence of pH, ionic strength and natural organic matter concentration on a MIP-Fluorescent sensor for the quantification of DNT in water

The effect of sample water chemistry on a carbon dot labeled molecularly imprinted polymer (AC-MIP) sensor for the detection of 2,4-dinitrotoluene (DNT) was investigated. Hydrogel MIP films were fabricated and tested in DNT solutions in various matrices, representative of natural water conditions, to assess applicability of the sensors to real water samples. The effect of pH, natural organic matter (NOM), ionic strength and cation type on the swelling of the hydrogel and fluorescence quenching was investigated. An increase in ionic strength from 1 mM to 100 mM produced a quenching amount of MIPs decreased of about 19 percent and 30 percent with NaCl and CaCl2 respectively. In the range of pH tested, from 4 to 9, quenching was higher at basic environment for both MIPs and non-imprinted polymers (NIPs) due to increased hydrogel swelling. NOM contributed to the background quenching, but the effect could be addressed by an adjusted calibration equation. In both lake and tap water, DNT concentrations read by the sensors were close to the values measured by HPLC, within 72 percent–105 percent of true values. The AC-MIP films fabricated in this work are promising materials for the detection of water contamination in the field and the quantitative analysis of DNT concentration

Characteristics of ultrafiltration ceramic membranes derived from alumoxane nanoparticles

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Interparticle effects in the cotransport of viruses and engineered nanoparticles in saturated porous media

The effects of P25 TiO2 nanoparticles on the transport in saturated porous media of the bacteriophage PP7 was investigated. Two levels of ionic strength were considered, given by monovalent and divalent cations, Na+ and Ca2+. The viruses and the P25 particles were characterized with respect to size and surface charge, by dynamic light scattering and electron microscopy. The breakthrough curves were obtained for suspensions of each particle and both combined, using UV absorbance to quantify P25 and RT-qPCR for PP7. In the single transport experiments, P25 was retained, while the viruses mostly eluted the sand bed. However, in the cotransport experiments, retention increased for the virus and decreased for the TiO2 nanoparticles under high viral content, due to heteroaggregation among the colloids in the incoming suspension, electrostatic interactions, and ripening. The interparticle interactions were modeled by DLVO theory, resulting in agreement with the experimental observations, which highlights the electrostatic nature.Fil: Gentile, Guillermina. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Blanco Fernandez, Maria Dolores. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Fidalgo de Cortalezzi, María M.. University of Missouri; Estados Unido