1,721,032 research outputs found
Functionalized SPIONs: The surfactant nature modulates the self-assembly and cluster formation
No full textThe authors report a systematic investigation on different surfactant-functionalized superparamagnetic iron oxide nanoparticles (SPIONs) in order to explore the possibility of tuning the particle size by choosing an appropriate amphiphilic mol. By combining small-angle neutron scattering and dynamic light scattering, a description of the functionalized SPION structure was obtained. The relationship between crit. micelle concn. and the efficiency in coating the SPION surface was established. A lack in the formation of a compact shell led to clusters formation
Nanoparticle technology: Addressing the fundamental roadblocks to protein biomarker discovery
No full textThe incorporation of affinity baits into N-isopropylacrylamide-hydrogel- based nanoparticles offers a novel technology that addresses the major analytical challenges of disease biomarker discovery. In solution in complex biologic fluids (e.g. blood or urine), core-shell bait-containing nanoparticles can perform three functions in one step: (a) sieve molecules according to size, (b) sequestrate and concentrate target analytes, and (c) protect analytes from degradation. © 2009 The Royal Society of Chemistry 2009
Cationic liposomes as efficient nanocarriers for the drug delivery of an anticancer cholesterol-based ruthenium complex
No full textAiming for novel tools for anticancer therapies, a ruthenium complex, covalently linked to a cholesterol-contg. nucleolipid and stabilized by co-aggregation with a biocompatible lipid, is here presented. The amphiphilic ruthenium complex, named ToThyCholRu, is intrinsically neg. charged and has been inserted into liposomes formed by the cationic 1,2-dioleyl-3-trimethylammoniumpropane chloride (DOTAP) to hinder the degrdn. kinetics typically obsd. for known ruthenium-based antineoplastic agents. The here described nanovectors contain up to 30% in moles of the ruthenium complex and are stable for several weeks. This drug delivery system has been characterized using dynamic light scattering (DLS), small angle neutron scattering (SANS), neutron reflectivity (NR) and ESR techniques. Fluorescence microscopy, following the incorporation of rhodamine-B within the ruthenium-loaded liposomes, showed fast cellular uptake in human carcinoma cells, with a strong fluorescence accumulation within the cells. The in vitro bioactivity profile revealed an important antiproliferative activity and, most remarkably, the highest ability in ruthenium vectorization measured so far. Cellular morphol. changes and DNA fragmentation provided evidence of an apoptosis-inducing activity, in line with several in vitro studies supporting apoptotic events as the main cause for the anticancer properties of ruthenium derivs. Overall, these data highlighted the crucial role played by the cellular uptake properties in detg. the anticancer efficacy of ruthenium-based drugs, showing DOTAP as a very efficient nanocarrier for their stabilization in aq. media and transport in cells. In vitro bioscreens have shown the high antiproliferative activity of ToThyCholRu-DOTAP liposomes against specific human adenocarcinoma cell types. Furthermore, these formulations have proved to be over 20-fold more effective against MCF-7 and WiDr adenocarcinoma cells with respect to the nude ruthenium complex AziRu we have previously described
Protocol for Investigating the Interactions Between Intrinsically Disordered Proteins and Membranes by Neutron Reflectometry
No full textSeveral intrinsically disordered proteins (IDPs) exhibit high affinity for lipid membranes. Among the different biophysical methods to probe protein-lipid interaction, neutron reflectometry (NR) can provide direct and structural detailed information on the location of the IDP with respect to the membrane. Supported lipid bilayers are commonly used as cell membrane models in such experiments. NR measurements can be collected on the supported lipid bilayer before and after the interaction with the IDP to characterize whether the protein molecules are mainly located on the membrane surface (interaction with the lipid headgroups), are penetrating into the hydrophobic region of the membrane (interaction with the lipid acyl chains), or are not interacting at all with the membrane. The lipid composition of the supported lipid bilayer can easily be tuned; hence the NR experiments can be designed to investigate selective IDP-lipid interactions.This chapter will describe the fundamental steps for performing an NR experiment and the subsequent data analysis aimed at characterizing IDP-lipid bilayer interactions. The specific case of an intrinsically disordered region (IDR) from the membrane protein Na+/H+ exchanger isoform 1 (NHE1) will be used as an example, but the same protocol can be easily adapted to other IDPs
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Effects of Hydrogel Nanoparticles as a Novel Adjuvant for a Purified Whole Inactivated Chikungunya Virus Vaccine
Full text linkThis thesis has been embargoed for 5 years and will not be available until December 2021 at the earliest.This thesis describes a novel nanotrap nanoparticle adjuvant for a purified whole inactivated Chikungunya CHIK virus vaccine and its immune response and level of toxicity. For a vaccine to be good candidate it must be able to invoke a strong immune response to the viral antigen without causing damage to the recipient. Most vaccines are formulated with an adjuvant, which is anything that has the ability to bolster the immune response to the vaccine. Nanoparticle pose as a promising alternative to the commonly used alum adjuvant. The novel chemistry of the nanoparticles used in this study allows them to deliver the drug to the desired area, gradually release their cargo, and stabilize and protect the vaccine. Following a 28-day mouse trail, blood sera from the placebo group, non-adjuvanted CHIK vaccine group and NP-adjuvanted CHIK vaccine group were tested for neutralizing antibodies. Each vaccine group was also tested for signs of toxicity. The neutralizing titers from the NP-adjuvanted vaccine group was substantially equivalent to the non-adjuanted vaccine group. Moreover, the author showed that the NPs were able to capture whole CHIK virus, remain adsorbed to the virus for an extended period of time and that the NPs were non-toxic
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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