Superhydrophobic surfaces with low and high adhesion made from mixed (hydrocarbon and fluorocarbon) 3,4-propylenedioxythiophene monomers

International audienceThis work concerns new superhydrophobic surfaces, generated by replacing long fluorocarbon chains, which bioaccumulate, with short chains whilst at the same time retaining oleophobic properties. Here, is described the synthesis of novel original 3,4-propylenedioxythiophene derivatives containing both a short fluorocarbon chain (perfluorobutyl) and a hydrocarbon chain of various lengths (ethyl, butyl and hexyl). Superhydrophobic (contact angle water > 150° ) surfaces with good oleophobic properties (60° > contact angle hexadecane > 80° ) have been obtained by electrodeposition using cyclic voltammetry. Surprisingly, the lowest hystereses and sliding angles (Lotus effect) are obtained with the shortest alkyl chains due to the presence of microstructures made of nanofibers on the surfaces, whereas, the longest alkyl chains leads to nanosheets with high adhesion (Petal effect). Such materials are potential candidates for biomedical applications

Marine anticancer agents: An overview with a particular focus on their chemical classes

UID/Multi/04378/2019 IF/00700/2014 grant number 216Z167 grant RTA 2015-00010-C03-02 No. PBA/MB/16/01 PDOC/19/02/01The marine environment is a rich source of biologically active molecules for the treatment of human diseases, especially cancer. The adaptation to unique environmental conditions led marine organisms to evolve different pathways than their terrestrial counterparts, thus producing unique chemicals with a broad diversity and complexity. So far, more than 36,000 compounds have been isolated from marine micro- and macro-organisms including but not limited to fungi, bacteria, microalgae, macroalgae, sponges, corals, mollusks and tunicates, with hundreds of new marine natural products (MNPs) being discovered every year. Marine-based pharmaceuticals have started to impact modern pharmacology and different anti-cancer drugs derived from marine compounds have been approved for clinical use, such as: cytarabine, vidarabine, nelarabine (prodrug of ara-G), fludarabine phosphate (pro-drug of ara-A), trabectedin, eribulin mesylate, brentuximab vedotin, polatuzumab vedotin, enfortumab vedotin, belantamab mafodotin, plitidepsin, and lurbinectedin. This review focuses on the bioactive molecules derived from the marine environment with anticancer activity, discussing their families, origin, structural features and therapeutic use.publishersversionpublishe

Surfactants with low fluorine content

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Synthesis, characterization and surface wettability of polythiophene derivatives containing semi-fluorinated liquid-crystalline segment

International audienceIn the scope of increasing our knowledge on the elaboration of smart surfaces, the aim of this work was to synthesize monomers as starting materials for the polymerization or copolymerization via electrochemical route. We report the synthesis and characterization of original structures containing a single phenyl unit bound, on one side, to a semi-fluorinated tail via a thioester connector and, on the other side, to a thiophene moiety. This design approach using cheap raw materials (a single phenyl ring as mesogenic core) associated to an electropolymerizable unit is of great interest in the development of liquid crystal low cost materials to build-up non-wetting surfaces based on the fluorophobic effect. The mesomorphic properties were characterized using differential scanning calorimetry and optical polarizing microscopy. The effect of the length of the fluorinated tail induced the formation of a smectic enantiotropic mesophase for F-hexyl and F-octyl tails. The polymerization of the films was performed in solution of sodium perchlorate in acetonitrile. Hydrophobic surfaces were obtained from the monomers containing a F-hexyl and F-octyl tail, while superhydrophobic surfaces (contact angle of water of 158°) were reached from the monomer containing a F-butyl tail

Influence of long alkyl spacers in the elaboration of superoleophobic surfaces with short fluorinated chains

International audienceIn order to produce extremely high oleophobic properties with a low fluorine content, long dodecyl spacers were introduced between a polymer and fluorinated chains in order to reduce the mobility of the fluorinated chains, especially short perfluorobutyl (F-butyl) chains. We report the synthesis and characterization of electrodeposited polymer surfaces obtained from original fluorinated 3,4-ethylenedioxypyrrole (EDOP) derivatives. Semi-fluorinated chains of three different lengths (F-octyl: PEDOPC12F8, F-hexyl: PEDOPC12F6 and F-butyl: PEDOPC12F4) were grafted to EDOP and separated with a n-dodecyl chain in order to reduce the mobility of F-butyl chains. For the first time, a surprisingly high contact angle of 138u was measured with hexadecane on PEDOPC12F4, although F-octyl tails are necessary to produce robust superoleophobic surfaces. By producing smooth surfaces, we successfully separate the influence of the intrinsic hydro- and oleophobicity and the surface structuration on the static contact angles of water and hexadecane. Here, the surface structuration increases the contact angle of hexadecane by 90u for PEDOPC12F4. The Cassie-Baxter equation predicts a porosity of 84.5% between the surface and a hexadecane droplet

Superhydrophobic and oleophobic surfaces containing wrinkles and nanoparticles of PEDOT with two short fluorinated chains

International audienceSuperhydrophobic and oleophobic surfaces are obtained by electrodeposition of original PEDOT derivatives containing two short fluorinated chains. The liquid-repellent properties are due to the combination of high intrinsic hydrophobicity and oleophobicity of polymers due the presence of two fluorinated chains, and the formation of wrinkles and spherical particles induced by the electrodeposition process. The presence of wrinkles and spherical particles and as a consequence the surface hydrophobicity and oleophobicity is correlated to the fluorinated chain length and electrochemical parameters (the deposition charge for the depositions at constant potential and the scan rate and number of scans for the depositions by cyclic voltammetry). Here, the increase in the number of wrinkles and spherical particles induce an increase in the surface roughness increasing especially the surface hydrophobicity while the surface oleophobicity is not always affected. However, it is possible to increase also the surface oleophobicity by a careful choice in the electrochemical parameters. This work also allows the elaboration of super liquid-repellent surfaces with low fluorine content (materials with low bioaccumulative potential)

Use of reconstructed human epidermis as alternative models for efficiency studies against the penetration of organophosphates

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Investigation of structure-surface properties relationship of semi-fluorinated polymerizable cationic surfactants

International audienceNovel hybrid hydrocarbon/fluorocarbon ammonium type surfactant monomers (surfmers) of the general formula RF (CH2)l N(CH3)2(CH2)m OCOCH = CH2 with (RF = C4F9, C6F13, C8F17, l = 4, 6, 11, and m = 2-11) were synthesized and characterized. They exhibit very low surface tension as well as low critical micellar concentrations down to 1.39 10 5 mol/L. Special attention was focused on the effect of the polymerizable moiety, the length of the hydrocarbon spacers, and the fluorinated chains on surface activities of the reactive surfactants as compared to hydrocarbon surfmer analogs. Results indicate that the acrylic function has a pronounced effect on increasing the hydrophobic micelle character. This was confirmed by surface tensions and average surfaces occupied by these molecules at the water-gas interface. The micellar sizes were investigated by dynamic light scattering

Conception de matériaux antibactériens par plasma et par électropolymérisation

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Superhydrophobic surface for anti-bioadhesion

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