Immobilization of controlled Pu:Am ratio on actinide-specific affinity monolith support developed in capillary and coupled to inductively coupled plasma mass spectrometry.

The objective of this work was to develop an actinide-specific monolithic support in capillary designed to immobilize precise Pu:Am ratios and its coupling to inductively coupled plasma mass spectrometry (ICP-MS) for immobilized metal affinity chromatography applications. This format offers many advantages, such as reducing the sample amount and waste production, which are of prime importance when dealing with highly active radioelements. Four organic phosphorylated-based monoliths were synthesized in situ through UV photo-polymerization in capillary and characterized. The capillary coupling to ICP-MS was set up in conventional laboratory using Th and Sm as chemical analogues of Pu and Am. A dedicated method was developed to quantify online Th and Sm amounts immobilized on the monolithic capillaries, allowing to select the best monolith candidate poly(BMEP-co-EDMA)adp. By precisely adjusting the elemental composition in the loading solutions and applying the developed quantification method, the controlled immobilization of several Th:Sm molar ratios onto the monolith was successful. Finally, the capillary ICP-MS coupling was transposed in a glove box and by applying the strategy developed to design the monolithic support using Th and Sm, the immobilization of a 10.5 ± 0.2 (RSD = 2.3%, n = 3) Pu:Am molar ratio reflecting Pu ageing over 48 years was achieved in a controlled manner on poly(BMEP-co-EDMA)adp. Hence, the new affinity capillary monolithic support was validated, with only hundred nanograms or less of engaged radioelements and can be further exploited to precisely determine differential interactions of Pu and Am with targeted biomolecules in order to better anticipate the effect of Am on Pu biodistribution.

Instrumental dead space: A glass ceiling for extremely low birth weight preterm infants? A dead space washout bench study.

BACKGROUND: When ventilating extremely low birth weight infants, clinicians face the problem of instrumental dead space, which is often larger than tidal volume. Hence, aggressive ventilation is necessary to achieve CO2 removal. Continuous tracheal gas insufflation can wash out CO2 from dead space and might also have an impact on O2 and water vapor transport. The objective of this bench study is to test the impact of instrumental dead space on the transport of CO2 , O2 , and water vapor and the ability of continuous tracheal gas insufflation to remedy this problem during small tidal volume ventilation. METHODS: A test-lung located in an incubator at 37°C was ventilated with pressure levels needed to reach different tidal volumes from 1.5 to 5 mL. End-tidal CO2 at the test-lung exit, O2 concentration, and relative humidity in the test-lung were measured for each tidal volume with and without a 0.2 L/min continuous tracheal gas insufflation flow. RESULTS: CO2 clearance was improved by continuous tracheal gas insufflation allowing a 28%-44% of tidal volume reduction. With continuous tracheal gas insufflation, time to reach desired O2 concentration was reduced from 20% to 80% and relative humidity was restored. These results are inversely related to tidal volume and are particularly critical below 3 mL. CONCLUSION: For the smallest tidal volumes, reduction of instrumental dead space seems mandatory for CO2 , O2 , and water vapor transfer. Continuous tracheal gas insufflation improved CO2 clearance, time to reach desired O2 concentration and humidification of airways and, thus, may be an option to protect lung development.

Towards comprehensive identification of pesticide degradation products following thermal processing below and above 120 °C: A review.

Characterising pesticide residues from a qualitative and quantitative point of view is key to both risk assessment in the framework of pesticide approval and risk management. In the European Union (EU), these concerns are addressed during the evaluation of active substances at the European level prior to marketing authorisation. In the framework of this review, we will focus on one specific item of the residue section, namely the effect of process (industrial or domestic transformation of the raw commodities) on the nature of the residue in food. A limited number of hydrolysis conditions defined by three parameters (temperature, pH and time) are set to be "representative of the most widely used industrial and domestic food processing technologies". These hydrolysis conditions, however, do not cover processes at temperatures higher than 120 °C, such as cooking with a conventional oven or in a pan, frying or using a microwave oven.

Metallic Nanoparticles Adsorbed at the Pore Surface of Polymers with Various Porous Morphologies: Toward Hybrid Materials Meant for Heterogeneous Supported Catalysis.

Hybrid materials consisting of metallic nanoparticles (NPs) adsorbed on porous polymeric supports have been the subject of intense research for many years. Such materials indeed gain from intrinsic properties, e.g., high specific surface area, catalytic properties, porous features, etc., of both components. Rational design of such materials is fundamental regarding the functionalization of the support surface and thus the interactions required for the metallic NPs to be strongly immobilized at the pore surface. Herein are presented some significant scientific contributions to this rapidly expanding research field. This contribution will notably focus on various examples of such hybrid systems prepared from porous polymers, whatever the morphology and size of the pores. Such porous polymeric supports can display pores with sizes ranging from a few nanometers to hundreds of microns while pore morphologies, such as spherical, tubular, etc., and/or open or closed, can be obtained. These systems have allowed some catalytic molecular reactions to be successfully undertaken, such as the reduction of nitroaromatic compounds or dyes, e.g., methylene blue and Eosin Y, boronic acid-based C-C homocoupling reactions, but also cascade reactions consisting of two catalytic reactions achieved in a row.

Contribution of the "Click Chemistry" Toolbox for the Design, Synthesis, and Resulting Applications of Innovative and Efficient Separative Supports: Time for Assessment.

The last two decades have seen the rapid expansion of click chemistry methodology in various domains closely related to organic chemistry. It has notably been widely developed in the area of surface chemistry, mainly because of the high-yielding character of reactions of the "click" type. Especially, this powerful chemical reaction toolbox has been adapted to the preparation of stationary phases from the corresponding chromatographic supports. A plethora of selectors can thus be immobilized on either organic, inorganic, or hybrid stationary phases that can be used in different chromatographic modes. This review first highlights the few different chemical ligation strategies of the "click" type that are up to now mainly devoted to the development of functionalized supports for separation sciences. Then, it gives in a second part an up-to-date survey of the different studies dedicated to the preparation of click chemistry-based chromatographic supports while highlighting the powerful and versatile character of the "click" ligation strategy for the design, synthesis, and developments of more and more complex systems that can find promising applications in the area of analytical sciences, in domains as varied as enantioselective separation, glycomics, proteomics, genomics, metabolomics, etc.

Molecularly Imprinted Hydrogels Selective to Ribavirin as New Drug Delivery Systems to Improve Efficiency of Antiviral Nucleoside Analogue: A Proof-of-Concept Study with Influenza A Virus.

This study describes the synthesis and evaluation of different imprinted hydrogels using ribavirin as template molecule. Ribavirin serves as a model molecule because it possesses a broad-spectrum antiviral effect against RNA viruses, which are expected as emerging viruses. The choice of monomers enables to stabilize the pre-polymerization complex and to synthesize biocompatible polymers. Predictive studies as well as experimental works conclude similar results on best ribavirin:monomers ratios. Thus, materials exhibit high selective cavities toward ribavirin. These affinities allow to show release profiles drastically different from the non-imprinted ones at two temperatures. The imprinted materials show a sustained profile able to release antiviral for more than 24 h. The hydrogels obtained are biocompatible with model cells retained, human lung epithelial BEAS-2B cells. Cell viability is excellent and pro-inflammatory response is insignificant when imprinted polymers are incubated with cells. Finally, viral tests carried out on Influenza A infected lung cells show that imprinted delivery systems delivering 1 to 3 µg of antiviral have the same efficiency as a medium containing 30 µg mL-1 of active agent. As a very interesting result, the molecularly imprinted polymers as drug delivery systems allow to increase the local concentration of antiviral, to improve their delivery when its bioavailability is low.

Raw and processed data used in non-covalent functionalization of single walled carbon nanotubes with Co-porphyrin and Co-phthalocyanine and its effect on field-effect transistor characteristics.

This scientific data article is related to the research work entitled "Non-Covalent functionalization of Single Walled Carbon Nanotubes with Fe-/Co-porphyrin and Co-phthalocyanine for Field-Effect Transistor Applications" published in "Organic electronics" (10.1016/j.orgel.2021.106212). In this work, we present the data of morphological, chemical and structural analyses of non-covalent functionalization of SWNTs with Co-porphyrin and Co-phthalocyanine. The analyses were performed by Raman spectroscopy, transmission electron microscopy as well as the electrical characterization of CNTFETs. This work is completed by the data of the theoretical calculations performed using Density Functional Theory (DFT).

Efficient and Recyclable Heterogeneous Catalyst Based on PdNPs Stabilized on a Green-Synthesized Graphene-like Nanomaterial: Effect of Surface Functionalization.

This work reports for the first time a straightforward and efficient approach to covalent surface functionalization of a sustainable graphene-like nanomaterial with abundant carboxylic acid groups. This approach results in an efficient and robust chelatant platform for anchoring highly dispersed ultrasmall palladium particles with excellent catalytic activity in the reduction of both cationic (methylene blue, MB) and anionic (eosin-Y, Eo-Y) toxic organic dyes. The large-specific-surface-area (SBET = 266.94 m2/g) graphene-like nanomaterial (GHN) was prepared through a green and cost-effective pyrolysis process from saccharose using layered bentonite clay as a template. To introduce a high density of carboxylic acid functions, GHN was first doubly functionalized by successive grafting reaction using two different strategies: (i) in the first case, GHN was first grafted by (3-glycidyloxypropyl) trimethoxysilane (GPTMS) and then bifunctionalized by chemical grafting of tris(4-hydroxyphenyl)methane triglycidyl ether (TGE). In the second case, the grafting order of the two molecules has been reversed. GHN-GPTMS-TGE provided the highest number of grafted reactive epoxy groups, and it was selected for further functionalization with carboxylic acid functions via a ring-opening reaction through a two-step hydrolysis (H2SO4)/oxidation (KMnO4) approach. The GHN nanomaterial bearing carboxylic acid groups was then treated with sodium hydroxide to produce a deprotonated carboxylic acid-rich platform. Finally, due to a high density of accessible chelatant carboxylic acid groups, GHN-COO- binds strongly a great amount of Pd2+ ions to form stable complexes which after reduction by NaBH4 leads to highly dispersed, densely anchored, and uniformly distributed nanoscale Pd particles (d ∼ 4.5 nm) on the surface of the functionalized GHN. The GHN-COO-@PdNPs nanohybrid proved to be highly efficient for dye reduction by NaBH4 in aqueous solution at room temperature. Moreover, because of the high stability of the as-prepared graphene-like supported PdNPs, it exhibited very good reusability and could be recycled up to eight times without any significant loss in activity.

Dataset for synthesis of conducting polymers nanocomposites based on aniline and 4-amino-benzylamine catalyzed by chromium (III) exchanged maghnite (Algerian MMT) via in situ polymerization.

In this data we report on conductors polymers nanocomposites synthesized by in situ polymerization of aniline (ANI) and/or 4-aminobenzylamine (4-ABA) in presence of chromium montmorillonite (MMT-Cr+3) and ammonium persulfate as oxidizing agent. Homopolymers and copolymers (PANI-co-4-ABA) were prepared at various initial monomer composition and were characterized by Fourier transform Infrared (FT-IR) and UV-vis spectroscopy, X-ray diffraction (XRD) and cyclic voltammeter. The data describes the behavior of the corresponding homopolymers Poly (4-ABA) and (PANI) and showed that the in-situ polymerization produced real nanocomposites containing aniline and 4-aminobenzylamine units and films of products exhibit good electrochemical properties.

Chitosan based self-assembled nanocapsules as antibacterial agent.

Creating an appropriate antibacterial disinfection system without forming any harmful compounds is still a major challenge and calls for new technologies for efficient disinfection and microbial control. Towards this aim, we report on the elaboration of biodegradable and biocompatible polymeric nanocapsules, also called hollow nanoparticles, for potential applications in antibiotic therapy. These nanomaterials are based on the self-assembly of charged polysaccharides, namely chitosan and alginate, onto gold nanoparticles as a sacrificial matrix (60 nm). Electrostatic interactions between the protonated amine groups of chitosan (+35 mV) and the carboxylate groups of alginate (- 20 mV) are the driving attraction force enabling the elaboration of well-ordered multilayer films onto the spherical substrate. The removal of the colloidal gold, via cyanide-assisted hydrolysis, is evidenced by time-dependent variation of the gold spectroscopic signature (30 min is required). TEM shows the obtention of nanocapsules. An inhibitory effect of these particles has been demonstrated during the growth of two representative bacteria in a liquid medium: Staphylococcus aureus (Gram-positive) (from 4.6% to 16.3% for gold nanomaterials + and from 18.6% to 34.9% for (chi+/alg-)n-chi+ nanocapsules) and Escherichia coli (Gram-negative) (from 5.4% to 20% for gold nanomaterials and from 23.7% to 40% for (chi+/alg-)n-chi+ nanocapsules). Acridine orange staining demonstrated the bactericidal effect of chitosan-based capsules. These findings demonstrate that (chitosan/alginate)n capsules can be exploited as new antibacterial material. Thus, we present a complementary approach to classical nanoparticles prepared by complexation between alginate and chitosan or other materials.

Cationic poly(cyclodextrin)/alginate nanocapsules: From design to application as efficient delivery vehicle of 4-hydroxy tamoxifen to podocyte in vitro.

Most of the drug molecules are partially insoluble in aqueous solution and then may accumulate in fat tissues hampering efficient therapy. Innovative drug delivery strategies have emerged in industry or academia over the last decades, however preserving the activity of the encapsulated drug, having high drug loading capacity and controlling drug release kinetics, are still challenging. In this context, we explored the preparation of new nanocarriers, namely nanocapsules, via a templating method, and using polysaccharides exhibiting biological functions. Cationic poly(cyclodextrin) (P(CD+)) and alginate (alg-) were initially self-assembled layer-by-layer on colloidal gold nanoparticles. Removal of gold nanoparticles was then induced thorough cyanide-assisted hydrolysis, enabling the recovery of nanocapsules. A hydrophobic drug known to allow the mutation of genes inside cells, namely 4-hydroxy-tamoxifen, was loaded within the nanocapsules' shell via inclusion with the cyclodextrin cavities. The so-designed nanomaterials were incubated with immortalized podocytes to investigate i) their incorporation inside cells and ii) their efficiency for in vitro 4-hydroxy-tamoxifen-induced CreERT2 recombination. This work undoubtedly highlights a proof-of-concept for drug delivery using polysaccharides-based capsules with host properties.

Synthesis of imprinted hydrogel microbeads by inverse Pickering emulsion to controlled release of adenosine 5'­monophosphate.

Herein, we propose the synthesis of a microspherical imprinted hydrogel meant for the controlled release of a nucleotide, adenosine 5'-monophosphate (5'-AMP). Indeed, molecularly imprinted polymers-based (MIPs) materials possess remarkable selective molecular recognition ability that mimicks biological systems. MIPs have been used in numerous applications and hold great promise for the vectorization and/or controlled release of therapeutics and cosmetics. But, the conception of imprinted hydrogels-based drug delivery systems that are able to release polar bioactive compounds is explored weakly. Herein, the synthesis of imprinted hydrogel microbeads by inverse Pickering emulsion is detailed. Microspheres showed a large 5'-AMP loading capacity, around 300 mg·g-1, and a high binding capacity comparatively to the non-imprinted counterpart. The MIP had a thermo-responsive release behavior providing sustained release of adenosine 5'-monophosphate in an aqueous buffer simulating both human skin pH and temperature.

Glucose-sensitive capsules based on hydrogen-bonded (polyvinylpyrrolidone / phenylboronic -modified alginate) system.

Glucose-responsive multilayer capsules have been produced through the layer-by-layer deposition of biodegradable polymers based on hydrogen bonding. The used polymers are alginate derivative and polyvinylpyrolidone (PVPON). Concentration-dependent glucose responsiveness was reached through chemical modification of alginate, selected as polyanion, with phenylboronic acid moieties (known to enable complexes with diols derivative) demonstrated that the alginate derivative self-assembles with the PVPON in accordance with (i) the formation of hydrogen bonding layer-by-layer assembly, and (ii) also evidence an enhancement of the stability versus the pH. We demonstrate that incorporating boronic acid moieties inside a polymer chain allows (i) glucose-responsiveness and (ii) using boronic moieties as hydrogen bond acceptor. This strategy was implemented for the fabrication of smart capsules employing calcium carbonate microparticles as a removable core template. This later enables to consider the loading of two probes. The porosity of the calcium carbonate microparticles template has been used to load the first probe (rhodamine b) and the other one has been loaded through electrostatic interaction with the carboxylate moiety in the alginate (methylene blue hydrate). Insulin has also been loaded as chemical of interest to demonstrate the interest of the present strategy.

Antibacterial hop extracts encapsulated in nanochitosan matrices.

Hops and the components extracted from them are well known antibacterial agents used in beers and as food preservatives, in formulations for topical applications on their own or together with other antimicrobial agents, in hormone replacement therapy, as antioxidants, tumor development antagonists, and angiogenesis inhibitors. Their shortcomings: very low bioavailability, bitter taste, and susceptibility to oxidative decomposition have limited their applications. We propose nanosized chitosan, an inexpensive, readily available biopolymer with a broad spectrum of antibacterial activity, as carrier for lupulone (L) and xanthohumol (X), two components of hops. Chitosan nanoparticles (CNP) and chitosan-based nanocomposites encapsulating lupulone (CNL) and xanthohumol (CNX) were prepared by ionotropic gelation using sodium tripolyphosphate (TPP) as crosslinker. Different preparative ratios and conditions were investigated and the nanoparticles obtained were characterized by FTIR, colloidal titration, size, zeta potential, and antimicrobial activity. The kinetics of the release of L/X from composites was studied in vitro. All the nanoparticles were active against several Gram-positive, Gram-negative, and Candida strains. Synergistic interactions were observed in all cases, although hops are known mainly for their activity against Gram-positive bacteria. All nanoparticles showed good stability over several months.

Glucose-sensitive polyelectrolyte microcapsules based on (alginate/chitosan) pair.

Novel chemical stimulus-responsive multilayer assemblies have been elaborated through the layer-by-layer deposition of oppositely charged polysaccharides on either flat or spherical surfaces. Concentration-dependent glucose responsiveness was obtained through chemical modification of alginate, selected as polyanion, with phenylboronic acid moieties. QCM measurements showed that the alginate derivate still self-assembles though electrostatically-driven interactions with chitosan at pH 4, and that the polysaccharides multilayer assemblies, as obtained after crosslinking, exhibit improved stability versus pH (in the range 4-9) as well as swelling ability in the presence of glucose-containing solution. Glutaraldehyde-mediated crosslinking was achieved through reaction with free primary amines of chitosan. This approach was further extended to the preparation of smart capsules using CaCO3 microparticles as dissolvable core templates. Success of the LbL deposition process, stability (pH range 4-9) of the multilayer assemblies and glucose-induced swelling were fully confirmed for the microcapsules. One of the major result of this study is that crosslinking prevents total dissolution of the capsules and enables modulating the permeability of the polysaccharide shell yielding controlled release on in-capsule entrapped low molecular weight molecules.

A lab-on-a-chip for monolith-based preconcentration and electrophoresis separation of phosphopeptides.

A microdevice combining online preconcentration and separation of phosphopeptides was developed in a glass microchip. An ethylene glycol methacrylate phosphate (EGMP), acrylamide (AM) and bisacrylamide (BAA) based monolith was synthesized within microchannels through a photo-driven process. Morphological investigations revealed a homogeneous monolithic structure composed of uniform nodules (∼0.8 µm), with a large pore volume (0.62 cm3 g-1) and sufficiently high specific surface area (34.1 m2 g-1). These features make the monolith particularly interesting for preconcentration purposes. Immobilization of Zr4+ ions on the phosphate groups present at the poly(EGMP-co-AM-co-BAA) monolith surface leads to immobilized metal affinity chromatography support. This monolith-Zr4+ showed a great capacity to capture phosphopeptides. Successful preconcentration and separation of a mixture of ERK2 derived peptides differing only by their phosphorylation degree and sites could be achieved with signal enhancement factors between 340 and 910 after only 7 min of preconcentration. This integrated microdevice represents a novel approach for phosphoproteomic applications.

Solid supports for extraction and preconcentration of proteins and peptides in microfluidic devices: A review.

Determination of proteins and peptides is among the main challenges of today's bioanalytical chemistry. The application of microchip technology in this field is an exhaustively developed concept that aims to create integrated and fully automated analytical devices able to quantify or detect one or several proteins from a complex matrix. Selective extraction and preconcentration of targeted proteins and peptides especially from biological fluids is of the highest importance for a successful realization of these microsystems. Incorporation of solid structures or supports is a convenient solution employed to face these demands. This review presents a critical view on the latest achievements in sample processing techniques for protein determination using solid supports in microfluidics. The study covers the period from 2006 to 2015 and focuses mainly on the strategies based on microbeads, monolithic materials and membranes. Less common approaches are also briefly discussed. The reviewed literature suggests future trends which are discussed in the concluding remarks.

Microscope-assisted UV-initiated preparation of well-defined porous polymer monolithic plugs in glass microchips for peptide preconcentration.

Herein, highly defined monolithic beds were prepared in glass microchips by photopolymerization of ethylene glycol methacrylate phosphate (EGMP), acrylamide, and N,N'-methylenebisacrylamide (BAA) using an epifluorescence microscope as UV-irradiation source. Such a fast and easy method allowed precise control of (i) the edge shape, (ii) the location along the microchannel, and (iii) the length of the monolithic plugs within glass microchips. The addition of hydroquinone, a polymerization inhibitor, to the prepolymerization mixture was beneficial for achieving local and robust incorporation of monoliths with sharp edges within microchannels. The monolith length was easily tuned from 160 to 400 µm through simple change in the magnification of the objective and was found to be repeatable (relative standard deviation <7.5%). Further application for on-chip monolith-assisted solid - phase extraction is demonstrated for fluorescently labeled peptide. Both binding and subsequent elution behaviors were found to fully agree with a cation-exchange mechanism in concordance with the presence of phosphate groups at the monolith surface. Graphical abstract In-chip microscope-UV-synthesis of monolithic plugs with sharp edges.

Silanized aryl layers through thiol-yne photo-click reaction.

Nanometer-scale multilayered coatings were prepared by sequential surface reactions on gold plates. First 4-ethynylphenyl organic layer was electrografted from the parent diazonium tetrafluoroborate salt providing reactive alkynylated gold plate (Au-Y). The latter served for clicking mercaptosilane via a thiol-yne photo-triggered reaction to obtain alkoxysilane-functionalized surface. The trialkoxysilane top groups in turn served as anchor sites for the final sol-gel coating resulting from the surface reaction between aminopropylsilane and tetraethoxysilane (TEOS). It is demonstrated that two coupling agents, namely, aryl diazonium salt and silane, can be coupled using photo-triggered thiol-yne click reaction, resulting in robust multilayered coatings. In addition, the process is versatile in that it offers the possibility to design patterned surfaces. The top sol-gel layer can in turn be reacted with aminosilane, therefore providing a reactive and functional surface that can be used for different applications given the reactivity of amine groups. This approach opens new avenues for photo-triggered click reactions of aryl layers from diazonium salts. It shows that the new class of surface modifiers and coupling agents has much to offer and continues to be renewed for achieving tightly bound, reactive top coatings.

Functionalization of nanomaterials with aryldiazonium salts.

This paper reviews the surface modification strategies of a wide range of nanomaterials using aryldiazonium salts. After a brief history of diazonium salts since their discovery by Peter Griess in 1858, we will tackle the surface chemistry using these compounds since the first trials in the 1950s. We will then focus on the modern surface chemistry of aryldiazonium salts for the modification of materials, particularly metallic, semiconductors, metal oxide nanoparticles, carbon-based nanostructures, diamond and clays. The successful modification of sp(2) carbon materials and metals by aryldiazonium salts paved the way to innovative strategies for the attachment of aryl layers to metal oxide nanoparticles and nanodiamonds, and intercalation of clays. Interestingly, diazotized surfaces can easily trap nanoparticles and nanotubes while diazotized nanoparticles can be (electro)chemically reduced on electrode/materials surfaces as molecular compounds. Both strategies provided organized 2D surface assembled nanoparticles. In this review, aryldiazonium salts are highlighted as efficient coupling agents for many types of molecular, macromolecular and nanoparticulate species, therefore ensuring stability to colloids on the one hand, and the construction of composite materials and hybrid systems with robust and durable interfaces/interphases, on the other hand. The last section is dedicated to a selection of patents and industrial products based on aryldiazonium-modified nanomaterials. After nearly 160 years of organic chemistry, diazonium salts have entered a new, long and thriving era for the benefit of materials, colloids, and surface scientists. This tempts us to introduce the terminology of "diazonics" we define as the science and technology of aryldiazonium salt-derived materials.