Publications by authors named "Luis M Leon"

Branched ionic cyclodextrins multilayers were assembled onto the surface of previously aminolyzed poly(ethylene terephthalate) in order to construct local drug delivery tailored platforms with potential applicability as materials for indwelling medical devices. The construction of the multilayers took place by the alternate deposition of ionic cyclodextrin derivatives and was characterized by surface zeta-potential measurements, X-ray photoelectron spectroscopy and, after fluorescent labeling of anionic branched cyclodextrins, by UV-vis spectroscopy and confocal fluorescence spectroscopy. Transmission electron microscopy is used for the first time to show the deposited coating, and an average thickness of ∼270nm for 20 bilayered covering was measured.

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The present study summarizes the formation and characterization of multilayers of polyacrylonitrile (PAN) membranes with β-cyclodextrin derivatives in order to be potentially interesting for triclosan (TR) controlled delivery with antibacterial purposes, as well as, for the removal of TR from wastewater. With this object, cationic and anionic branched β-cyclodextrins (bβCDs) were incorporated by layer-by-layer (LbL) process onto previously synthesized and hydrolyzed PAN membranes. FTIR, XPS and labelling with fluoresceinamine (FA) let to study the formation and stability of the prepared multilayered systems.

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AbstractIn February 2014, the Malaria Elimination Working Group, in partnership with the Peruvian Ministry of Health (MoH), hosted its first international conference on malaria elimination in Iquitos, Peru. The 2-day meeting gathered 85 malaria experts, including 18 international panelists, 23 stakeholders from different malaria-endemic regions of Peru, and 11 MoH authorities. The main outcome was consensus that implementing a malaria elimination project in the Amazon region is achievable, but would require: 1) a comprehensive strategic plan, 2) the altering of current programmatic guidelines from control toward elimination by including symptomatic as well as asymptomatic individuals for antimalarial therapy and transmission-blocking interventions, and 3) the prioritization of community-based active case detection with proper rapid diagnostic tests to interrupt transmission.

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This study aims to synthesize, characterize and investigate the water solubility and cytotoxicity of branched anionic/cationic β-cyclodextrins (bβCDs) obtained by reaction with epichlorohydrin and chloroacetic acid or choline chloride, respectively, by a single step polycondensation reaction. Obtained ionic bβCDs were investigated as an attempt to comparatively study anionic and cationic bβCDs. Water solubility of both ionic derivatives was similar (400 mg/mL) at neutral and basic pHs and remarkably higher than that of their neutral homologues.

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Cellulose nanocrystals (CNC), extracted from microcrystalline cellulose by acid hydrolysis, were grafted by ring opening polymerization of L-Lactide initiated from the hydroxyl groups available at their surface and two different CNC:L-lactide ratios (20:80 and 5:95) were obtained. The resulting CNC-g-PLLA nanohybrids were incorporated in poly(lactic acid) (PLA) matrix by an optimized extrusion process at two different content (1 wt.% and 3 wt.

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Conjugated polyimides (PI) are successfully synthesized by chemical imidization through in situ silylation of diamines by the alteration of different donor-acceptor monomers. A detailed photophysical characterization is performed in the monomers and different polymers in tetrahydrofuran solutions. The emission spectra of the related donor-acceptor polymers with electron withdrawing cyano groups showed broader and more intense fluorescence bands in comparison to the polymer without -CN groups.

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