Electrospun Nanomaterials: Applications in Food, Environmental Remediation, and Bioengineering

This research was funded by the Spanish Ministerio de Economía y Competitividad, grant number MAT-2017-86805-R,and Spanish Ministerio de Ciencia e Innovación (MCI)—Agencia Estatal de Investigación (AEI)/Fondo Europeo de Desarrollo Regional (FEDER), grant number RTI2018-101969-J-I00

Formation of Multicolor Nanogels Based on Cationic Polyfluorenes and Poly(methyl vinyl ether-alt-maleic monoethyl ester): Potential Use as pH-Responsive Fluorescent Drug Carriers

In this study, we employed the copolymer poly(methyl vinyl ether-alt-maleic monoethyl ester) (PMVEMA-Es) and three fluorene-based cationic conjugated polyelectrolytes to develop flu orescent nanoparticles with emission in the blue, green and red spectral regions. The size, Zeta Potential, polydispersity, morphology, time-stability and fluorescent properties of these nanoparticles were characterized, as well as the nature of the interaction between both PMVEMA-Es and fluorescent polyelectrolytes. Because PMVEMA-Es contains a carboxylic acid group in its structure, the effects of pH and ionic strength on the nanoparticles were also evaluated, finding that the size is responsive to pH and ionic strength, largely swelling at physiological pH and returning to their initial size at acidic pHs. Thus, the developed fluorescent nanoparticles can be categorized as pH-sensitive fluorescent nanogels, since they possess the properties of both pH-responsive hydrogels and nanoparticulate systems. Doxorubicin (DOX) was used as a model drug to show the capacity of the blue-emitting nanogels to hold drugs in acidic media and release them at physiological pH, from changes in the fluorescence properties of both nanoparticles and DOX. In addition, preliminary studies by super-resolution confocal microscopy were performed, regarding their potential use as image probes

Physico-Chemically Distinct Nanomaterials Synthesized from Derivates of a Poly(Anhydride) Diversify the Spectrum of Loadable Antibiotics

Recent advances in the field of nanotechnology such as nanoencapsulation offer new biomedical applications, potentially increasing the scope and efficacy of therapeutic drug delivery. In addition, the discovery and development of novel biocompatible polymers increases the versatility of these encapsulating nanostructures, enabling chemical properties of the cargo and vehicle to be adapted to specific physiological requirements. Here, we evaluate the capacity of various polymeric nanostructures to encapsulate various antibiotics of different classes, with differing chemical structure. Polymers were sourced from two separate derivatives of poly(methyl vinyl ether-alt-maleic anhydride) (PMVE/MA): an acid (PMVE/MA-Ac) and a monoethyl ester (PMVE/MA-Es). Nanoencapsulation of antibiotics was attempted through electrospinning, and nanoparticle synthesis through solvent displacement, for both polymers. Solvent incompatibilities prevented the nanoencapsulation of amikacin, neomycin and ciprofloxacin in PMVE/MA-Es nanofibers. However, all compounds were successfully loaded into PMVE/MA-Es nanoparticles. Encapsulation efficiencies in nanofibers reached approximately 100% in all compatible systems; however, efficiencies varied substantially in nanoparticles systems, depending on the tested compound (14%–69%). Finally, it was confirmed that both these encapsulation processes did not alter the antimicrobial activity of any tested antibiotic against Staphylococcus aureus and Escherichia coli, supporting the viability of these approaches for nanoscale delivery of antibioticsThis research was funded by the Spanish Ministerio de Economía y Competitividad, grant numbers MAT-2017-86805-R and MAT-2014-53282-R,and Spanish Ministerio de Ciencia e Innovación (MCI)—Agencia Estatal de Investigación (AEI)/Fondo Europeo de Desarrollo Regional (FEDER), grant number RTI2018-101969-J-I0

Analytical Evaluation of the Ratio Between Injection and Space-Charge Limited Currents in Single Carrier Organic Diodes

An analytical, complete framework to describe the current-voltage (I-V) characteristics of organic diodes without the use of previous approaches, such as injection or bulk-limited conduction is proposed. Analytical expressions to quantify the ratio between injection and space-charge-limited current from experimental I-V characteristics in organic diodes have been derived. These are used to propose a numerical model in which both bulk transport and injection mechanisms are considered simultaneously. This procedure leads to a significant reduction in computing time with respect to previous rigorous numerical models. In order to test the model, different diode structures based on two different polymers: poly(2-methoxy-5-{3',7'-dimethyloctyloxy}-p-phenylenevinylene) (MDMO-PPV) and a derivative of the poly (2,7-fluorene phenylidene) [PFP:(CN)2], have been fabricated. The present model is excellently fitted to experimental curves and yields the microscopic parameters that characterize the active layer

O-esteres de alfa-oxoominas Sintesis, estudio fotoquimico y evaluacion como fotoiniciadores de polimerizacion

Centro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai

O-ésteres de alfa-oxooximas. Síntesis, estudio fotoquímico y evaluación como fotoiniciadores de polimerización

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química. Fecha de lectura: 09-05-199

Electrospun Nanomaterials: Applications in Food, Environmental Remediation, and Bioengineering

Among the large number of methods to fabricate nanofibers, electrospinning stands out because of its simplicity and versatility [...

Fish Skin Mucus Extracts: An Underexplored Source of Antimicrobial Agents

The slow discovery of new antibiotics combined with the alarming emergence of antibiotic-resistant bacteria underscores the need for alternative treatments. In this regard, fish skin mucus has been demonstrated to contain a diverse array of bioactive molecules with antimicrobial properties, including peptides, proteins, and other metabolites. This review aims to provide an overview of the antimicrobial molecules found in fish skin mucus and its reported in vitro antimicrobial capacity against bacteria, fungi, and viruses. Additionally, the different methods of mucus extraction, which can be grouped as aqueous, organic, and acidic extractions, are presented. Finally, omic techniques (genomics, transcriptomics, proteomics, metabolomics, and multiomics) are described as key tools for the identification and isolation of new antimicrobial compounds. Overall, this study provides valuable insight into the potential of fish skin mucus as a promising source for the discovery of new antimicrobial agents

Theoretical and experimental study of the bleaching of a dye in a film-polymerization process

The quantum efficiency and the molar-absorption coefficients of different phenothiazine dyes are obtained by means of fitting the experimental data of transmittance as a function of time. An analytical expression for the intensity transmitted in a photopolymerizable holographic material is obtained, and good agreement between theory and experience is also achieved. The analysis of these parameters is of fundamental quantities in the photochemical characterization of holographic recording materials.This study was supported by the Direcció General d'Ensenyaments Universitaris i Investigació de la Generalitat Valenciana, Spain (Project GV-C-CN-06-064-96)