DMTs and Covid-19 severity in MS: a pooled analysis from Italy and France

We evaluated the effect of DMTs on Covid-19 severity in patients with MS, with a pooled-analysis of two large cohorts from Italy and France. The association of baseline characteristics and DMTs with Covid-19 severity was assessed by multivariate ordinal-logistic models and pooled by a fixed-effect meta-analysis. 1066 patients with MS from Italy and 721 from France were included. In the multivariate model, anti-CD20 therapies were significantly associated (OR = 2.05, 95%CI = 1.39–3.02, p < 0.001) with Covid-19 severity, whereas interferon indicated a decreased risk (OR = 0.42, 95%CI = 0.18–0.99, p = 0.047). This pooled-analysis confirms an increased risk of severe Covid-19 in patients on anti-CD20 therapies and supports the protective role of interferon

Synthesis and characterization of jacalin-gold nanoparticles conjugates as specific markers for cancer cells

New nanobiocomposites that combine nanoparticles and biomolecules have been shown very relevantfor medical applications. Recently, cancer diagnostics and treatment have benefited from the develop-ment of nanobiocomposites, in which metallic or magnetic nanoparticles are conjugated with specificbiomolecules for selective cell uptake. Despite recent advances in this area, the biomedical applicationsof these materials are still limited by the low efficiency of functionalization, low stability, among otherfactors. In this study, we report the synthesis of jacalin-conjugated gold nanoparticles, a nanoconjugatewith potential application in medical areas, especially for cancer diagnosis. Jacalin is a lectin protein and itwas employed due to its ability to recognize the Gal 1-3GalNAc disaccharide, which is highly expressedin tumor cells. Gold nanoparticles (AuNPs) were synthesized in the presence of generation 4 polyami-doamine dendrimer (PAMAM G4) and conjugated with fluorescein isothiocyanate (FITC)-labeled jacalin.The AuNPs/jacalin nanoconjugates were characterized by transmission electron microscopy (TEM),dynamic light scattering (DLS) and vibrational spectroscopy (FTIR). We also performed an investigationusing isothermal titration calorimetry (ITC) and fluorescence quenching measurements to understandthe interactions occurring between the AuNPs and jacalin, which revealed that the nanoconjugate for-mation is driven by an entropic process with good affinity. Furthermore, in vitro tests revealed that theAuNPs/jacalin-FITC nanoconjugates exhibited higher affinity for leukemic K562 cells than for healthymononuclear blood cells, which could be useful for biomedical applications, including cancer cells imaging.FAPES

The Degree of Oxidation of Graphene Oxide

10.3390/nano11030560NANOMATERIALS11

The processing of polyelectrolyte-covered magnetite nanoparticles in the form of nanostructured thin films

Magnetic nanoparticles are promising for a variety of applications, such as biomedical devices, spin electronics, magnetic data storage media, to name a few. However, these goals may only be reached if stable and organized structures are fabricated. In this article, we report on a single-step synthetic route with the coprecipitation method, in which iron oxide magnetic nanoparticles (Fe3O4 NPs) were stabilized in aqueous media using the poly(diallyldimethylammonium chloride) (PDAC) polyelectrolyte. The Fe3O4 NPs had a diameter of ca. 5 nm, according to transmission electron microscopy (TEM) images, being arranged in an inverse spinel structure typical of magnetite. An investigation with infrared spectroscopy indicated that the mechanisms of stabilization in the polymer matrix were based on the interaction between quaternary amide groups from PDAC and the nanoparticle surface. The Fe3O4-PDAC NPs exhibited considerable magnetic susceptibility, with a monotonic increase in the magnetization with decreasing temperature. These Fe3O4-PDAC NPs were immobilized in layer-by-layer (LbL) films, being alternated with layers of poly(vinylsulfonic acid) (PVS). The LbL films were much rougher than typical films made with polyelectrolytes, and Fe3O4-PDAC NPs have been responsible for the high electrocatalytic activity toward H2O2 reduction, with an overpotential shift of 0.69 V. Overall, the stability, magnetic properties and film-forming ability indicate that the Fe3O4-PDAC NPs may be used for nanoelectronics and bioelectrochemical devices requiring reversible and magnetic redox materials.FAPESPFAPESP [2009/18618-5, 2009/15558-1, 2011/01541-0]CAPESCAPESCNPqCNPq [307436/2008-0, 304255/2010-6]INEOINEORede NanoBioMedBrasil (CAPES)Rede NanoBioMed-Brasil (CAPES

Accelerated synthesis of graphene oxide from graphene

10.3390/nano11020551Nanomaterials1121-

The Degree of Oxidation of Graphene Oxide

We show that the degree of oxidation of graphene oxide (GO) can be obtained by using a combination of state-of-the-art ab initio computational modeling and X-ray photoemission spectroscopy (XPS). We show that the shift of the XPS C1s peak relative to pristine graphene, ΔEC1s, can be described with high accuracy by ΔEC1s=A(cO−cl)2+E0, where c0 is the oxygen concentration, A=52.3 eV, cl=0.122, and E0=1.22 eV. Our results demonstrate a precise determination of the oxygen content of GO samples

Hot Hole Photoelectrochemistry on Au@SiO₂@Au Nanoparticles

There is currently a worldwide need to develop efficient photocatalytic materials that can reduce the high-energy cost of common industrial chemical processes. One possible solution focuses on metallic nanoparticles (NPs) that can act as efficient absorbers of light due to their surface plasmon resonance. Recent work indicates that small NPs, when photoexcited, may allow for efficient electron or hole transfer necessary for photocatalysis. Here we investigate the mechanisms behind hot hole carrier dynamics by studying the photodriven oxidation of citrate ions on Au@SiO₂@Au core–shell NPs. We find that charge transfer to adsorbed molecules is most efficient at higher photon energies but still present with lower plasmon energy. On the basis of these experimental results, we develop a simple theoretical model for the probability of hot carrier–adsorbate interactions across the NP surface. These results provide a foundation for understanding charge transfer in plasmonic photocatalytic materials, which could allow for further design and optimization of photocatalytic processes

Pseudocapacitive conjugated polyelectrolyte/2D electrolyte hydrogels with enhanced physico-electrochemical properties

Conducting polymer hydrogels (CPHs) are an attractive class of materials that synergize the electrical properties of organic semiconductors with the physical properties of hydrogels. Of particular interest is the implementation of CPHs as electrode materials for electrochemical energy storage by taking advantage of redox-tunable conjugated backbones and the large electroactive surface area. Herein, the use of 2D electrolytes as an effective post-polymerization additive to enhance the pseudocapacitive performance of CPHs, is demonstrated. By using the self-doped conjugated polyelectrolyte CPE-K hydrogel as a model system, improvements in cycling stability, specific capacitance and working voltage window upon addition of the 2D electrolytes, are shown. Furthermore, positively charged 2D electrolytes to be more effective than their negatively charged counterparts are revealed. Rheology measurements and SEM imaging indicate that the 2D electrolytes serve as non-covalent cross-linkers that help in forming a mechanically more robust and highly percolated conducting network. These results provide a new and simple to execute post-polymerization strategy to optimize the electrochemical performance of CPH-based pseudocapacitors.National Research Foundation (NRF)This work was supported by the National University of Singapore start up grant R143-000-A97-133 and the Medium-Sized Centre (MSC) grant from the National Research Foundation (NRF) of Singapore, Prime Minister's Office. G.Q. acknowledges funding from the President's Graduate Fellowship (PGF) under the National University of Singapore