Design and Fabrication of Polyvinylpyrrolidone-based Intelligent Materials Suitable for Controlled Release and Wound Treatment

Polyvinylpyrrolidone (PVP) is probably one of the most utilized pharmaceutical polymers with applications ranging from blood plasma substitute to nanoparticle drug delivery since its synthesis in 1938. It is a highly biocompatible, non-toxic and transparent film-forming polymer. Although high solubility of PVP in an aqueous environment is advantageous, it still poses several problems for some applications in which sustained targeting and release are needed, or hydrophobic drug inclusion and delivery systems are to be designed. For this reason, in the field of controlled drug release, it is often used as an additive and not as a protagonist. On the other hand, in case of wound treatment, PVP can be a suitable biopolymer for the design of wound dressings due to its capacity to inhibit the crystallinity of several drugs, opening to their topical application, and its adhesive properties to the skin. Therefore, the main goal of this Ph.D. was to demonstrate that this underestimated synthetic polymer can be a proper based material for the design, the fabrication and the formulation of new smart wound dressings for the delivery of antibiotic and antioxidant compounds. In the first part of this Ph.D. study, PVP and acetic acid (AcOH) were used to inhibit the crystallization of the antibiotic Ciprofloxacin (Cipro) and to prepare transparent PVP foils as well as nanofiber mats. The presence of the antibiotic and the acid inside of the PVP matrix caused a plasticizer effect of these ingredients in the final mechanical properties of the films. Both films and nanofibers were able to release the Cipro, and an antibacterial synergism between acetic acid and the antibiotic were highlighted in vitro antibacterial assay. The PVP/Cipro/AcOH materials showed biocompatibility and a different rate of resorption in an in vivo wound mice model. In the second part of the Ph.D., a multifunctional polyvinylpyrrolidone/hyaluronic acid-based bilayer construct for sequential delivery of cutaneous antiseptic and antibiotic was designed and fabricated by using two scalable methodologies. The bilayer material showed strong adhesion to skin, effective antibacterial activity against three strains, biocompatibility, hemocompatibility, anti-inflammatory properties both in vitro and in vivo, resorption by the skin and accelerate the wound closure in mice model. Then, the PVP/Cipro/AcOH films and nanofibers were further characterized on an infected wound model based on ex-vivo human skin. The materials resulted non-toxic and with suitable profiles of the release of Cipro inside of the skin. Moreover, they highlighted a strong antibacterial activity against biofilms infection of Pseudomonas aeruginosa and, especially, in case of the films they were able to eradicate completely the biofilms from the skin. Finally, PVP was combined with the dietary phenolic compounds, p-coumaric acid (PCA). The introduction of the PCA in transparent films led to an increase of the hydrophobicity of the PVP-based matrix. Indeed, changes in water contact angles, water uptake and the rate of dissolution in water were found. Furthermore, the new biocomposites were investigated as drug delivery system of two model drugs and their antioxidant and anti-inflammatory activity were analyzed in vitro and in vivo, respectively. In conclusions, several PVP-based wound dressings were designed and fabricated, demonstrating their potential efficacy for the treatment of infected wounds, burns, and chronic wounds

Âmbito da categoria de dignidade na reflexão moral de Arturo Andrés Roig

Este artículo busca profundizar aspectos de la propuesta filosófica de Arturo Andrés Roig con el objetivo de analizar un concepto fundamental de su reflexión moral: la dignidad. El punto de partida es la referencia al concepto kantiano de dignidad supuesto en la enunciación de la “moral de la emergencia”. Luego, se retoman las tesis desarrolladas por Roig en las cuales se resignifican las categorías de “oikeiosis” y “conciliatio” para una ampliación de los alcances de la noción de dignidad.This article discusses aspects of the philosophical proposal of Arturo Andrés Roig with the aim of analyzing a fundamental concept in his moral reflection: dignity. The starting point is the reference to the Kantian concept of dignity supposed in the enunciation of the “morality of emergence”. Then, the study takes the thesis developed by Roig which give a new meaning to categories of “oikeiosis” and “conciliatio” for widening the scope of the notion of dignity.Este artigo procura aprofundar os aspectos da proposta filosófica de Arturo Andrés Roig, com o objetivo de analisar um conceito fundamental de sua reflexão moral: a dignidade. O ponto de partida é a referência ao conceito kantiano de dignidade suposto no enunciado da “moral da emergência”. Logo, retomam-se as teses desenvolvidas por Roig nas quais resinificam-se as categorias de “oikeiosis” e “conciliatio” para um alargamento dos alcances da noção de dignidade.Fil: Contardi, Laura Aldana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentina. Universidad del Aconcagua; Argentin

Utopian function and human condition : inflections from Arturo Andrés Roig’s thought

Centramos la atención en la noción de “función utópica" del pensamiento de Arturo Andrés Roig. El problema se aborda partiendo del vínculo que se establece entre la función utópica y la condición humana. Apelamos al análisis de algunos textos de Ernst Bloch para mostrar los argumentos que esgrime en relación con el tratamiento de la utopía. A partir de la consideración de la función utópica como un ejercicio crítico mostramos que esta función implica un modo de habitar el hombre en el mundo. En otras palabras, trazamos un itinerario que lleva el propósito de esclarecer uno de los ejes que atraviesa la obra de Arturo Andrés Roig: la dimensión antropológica.We focus our attention on the concept “utopian function" of thought by Arturo Andrés Roig. This question starts with the link between “utopian function" and “human condition". We appeal to the analysis of some texts of Ernst Bloch in order to show the arguments he presents in relation to the treatment of utopia. From the consideration of utopian function as a critical exercise, we seek to show that this function involves a way of inhabiting the human being in the world. In other words, we draw up an itinerary which has the purpose of clarifying one axis that runs through the work of Arturo Andrés Roig: the anthropological dimension.Fil: Contardi, Laura Aldana. CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas) - Universidad Nacional de Cuy

Evaluation of Drug Delivery and Efficacy of Ciprofloxacin-Loaded Povidone Foils and Nanofiber Mats in a Wound-Infection Model Based on Ex Vivo Human Skin

Topical treatment of wound infections is often a challenge due to limited drug availability at the site of infection. Topical drug delivery is an attractive option for reducing systemic side effects, provided that a more selective and sustained local drug delivery is achieved. In this study, a poorly water-soluble antibiotic, ciprofloxacin, was loaded on polyvinylpyrrolidone (PVP)-based foils and nanofiber mats using acetic acid as a solubilizer. Drug delivery kinetics, local toxicity, and antimicrobial activity were tested on an ex vivo wound model based on full-thickness human skin. Wounds of 5 mm in diameter were created on 1.5 × 1.5 cm skin blocks and treated with the investigated materials. While nanofiber mats reached the highest amount of delivered drug after 6 h, foils rapidly achieved a maximum drug concentration and maintained it over 24 h. The treatment had no effect on the overall skin metabolic activity but influenced the wound healing process, as observed using histological analysis. Both delivery systems were efficient in preventing the growth of Pseudomonas aeruginosa biofilms in ex vivo human skin. Interestingly, foils loaded with 500 µg of ciprofloxacin accomplished the complete eradication of biofilm infections with 1 × 109 bacteria/wound. We conclude that antimicrobial-loaded resorbable PVP foils and nanofiber mats are promising delivery systems for the prevention or topical treatment of infected wounds

El desarrollo de colecciones y la selección de recursos en la biblioteca universitaria. México D. F.: UNAM, 2003. x, 143 p. (Sistemas bibliotecarios de Información y Sociedad)

Reseña de El desarrollo de colecciones y la selección de recursos en la biblioteca universitaria de María del Carmen Negrete Gutiérrez, realizada por Silvia ContardiFil: Contardi, Silvia. Universidad de Buenos Aires; Argentin

La Natación

La Natación es una multimedia educativa, en español, construida para dar apoyo a los alumnos, durante la enseñanza de los diferentes estilos de natación. Los contenidos que incluye son: Croll, Espalda, Pecho y Mariposa. Ofrece un recorrido interactivo con textos, imágenes, audios y videos producidos por su autor. Está dirigida a alumnos de 6º de secundaria entre 17 y 18 años de edad, que nadan aproximadamente hace 6 meses, con el fin de perfeccionar los estilos de natación mencionados.Este recurso ha sido recuperado en soporte DVD, desde la Biblioteca del Instituto Superior de Formación Docente Nº 84.Instituto Superior de Formación Docente Nº 8