Determining the Optimal Conditions for the Production by Supercritical CO2 of Biodegradable PLGA Foams for the Controlled Release of Rutin as a Medical Treatment

Poly(D,L,-lactide-co-glycolide) (PLGA) foam samples impregnated with rutin were successfully produced by supercritical foaming processes. A number of parameters such as pressure (80–200 bar), temperature (35–55 C), depressurization rate (5–100 bar/min), ratio lactide:glycolide of the poly(D,L,-lactide-co-glycolide) (50:50 and 75:25) were studied to determine their effect on the expansion factor and on the glass transition temperature of the polymer foams and their consequences on the release profile of the rutin entrapped in them. The impregnated foams were characterized by scanning electron microscopy, differential scanning calorimetry, and mercury intrusion porosimetry. A greater impregnation of rutin into the polymer foam pores was observed as pressure was increased. The release of rutin in a phosphate buffer solution was investigated. The controlled release tests confirmed that the modification of certain variables would result in considerable differences in the drug release profiles. Thus, five-day drug release periods were achieved under high pressure and temperature while the depressurization rate remained low.This research was funded by Spanish Ministry of Economy, Industry and Competitiveness: CTQ2017-86661-R

From olive leaves to spherical nanoparticles by one-step RESS process precipitation

In this work, spherical nanoparticles to be used in cosmetic, agro food or pharmaceutical industries have been directly precipitated from olives leaves in one-step RESS process. The leaves were brought into contact with supercritical CO2, and a fraction of the compounds from the flavone and flavonol families that can be found in the leaves were dissolved; then, by depressurizing the vessel, these compounds formed particles in the nanometer range. A complete factorial design was generated to thoroughly determine the influence from the main parameters on the RESS process with respect to the precipitated nanoparticles and their heterogeneity. Their antioxidant activity was also evaluated. Different pressures (250-350 bar), temperatures (60 and 100 degrees C), leaves sample weights (2 and 4 g) and cosolvent volumes, namely ethanol (9 and 18 mL), were studied as the main parameters that could affect the solvation and precipitation of the particle with active compounds in the leaves. Other parameters such as contact time (1 h) or nozzle size diameter (100 mu m) remained unchanged. The antioxidant activity was evaluated by means of the radical scavenging method using the radical 2,2-diphenyl-1-picrylhydrazole (DPPH). Spherical particles with diameters in the range of 55 nm to 4 mu m were obtained. Lower pressures and higher temperatures seemed to result in a reduction of the mean particle size. Greater volume of cosolvent is also recommended to reduce mean particle size. However, lower pressure, temperature and volume of cosolvent seems to promote a greater homogeneity of the particles. By means of chromatographic analyses, the main compounds, responsible for the antioxidant activity, such as oleuropein, quercetin or apigenin among others were identified

Structural Modification of Polymers Functionalized with Mango Leaf Extract by Supercritical Impregnation: Approaching of Further Food and Biomedical Applications

Identifying new polymers from natural resources that can be effectively functionalized can have a substantial impact on biomedical devices and food preservation fields. Some of these polymers would be made of biodegradable, renewable and compostable materials, and present the kind of porosity required to effectively carry active compounds that confer on them the desired properties for their intended applications. Some natural extracts, such as mango leaf extract, have been proven to have high levels of antioxidant, antimicrobial or anti-inflammatory properties, making them good candidates for controlled-release applications. This work intends to investigate the supercritical impregnation of different types of polymers (ABS, PETG, TPU, PC and PCL) with mango leaf extract. The influence of temperature and pressure on the polymers' structure (swelling and foaming processes) and their different behaviors have been analyzed. Thus, TPU and PC experience minimal structural modifications, while PETG, PCL and ABS, on the other hand, suffer quite significant structural changes. TPU and PETG were selected as the representative polymers for each one of these behaviors to delve into mango leaf extract impregnation processes. The bioactive capacity of the extract is present in either impregnated polymer, with 25.7% antioxidant activity by TPU processed at 35 degrees C and 100 bar and 32.9% antioxidant activity by PETG impregnated at 75 degrees C and 400 ba

Foaming of Polycaprolactone and Its Impregnation with Quercetin Using Supercritical CO2

Foamed polycaprolactone impregnated with quercetin was carried out with a batch foaming technique using supercritical CO2. The experimental design was developed to study the influence of pressure (15–30 MPa), temperature (308–333 K), and depressurization rate (0.1–20) on the foam structure, melting temperature, and release tests of composites. The characterization of the experiments was carried out using scanning electron microscopy, X-ray di ractometer, and di erential scanning calorimetry techniques. It was observed that the porosity created in the polymer had a heterogeneous structure, as well as the impregnation of the quercetin during the process. On the other hand, controlled release tests showed a significant delay in the release of quercetin compared to commercial quercetin

Deposition of CAP/Antioxidants Systems on Silica Particles Using the Supercritical Antisolvent Process

Supercritical carbon dioxide has been used to deposit co-precipitates of natural antioxidants with a polymer onto silica microparticles. The supercritical antisolvent process (SAS) was carried out with the antioxidants by introducing the silica microparticles into the precipitator vessel. Two di erent configurations were employed to pump the solution. In one configuration, the antioxidant and the polymer were dissolved and injected together through a nozzle. In the second configuration, the antioxidant and the polymer were dissolved in di erent solutions and sprayed through di erent nozzles. The use of operating conditions significantly above the critical point (180 bar and 323 K) led to the formation of composites made up of co-precipitates and silica. Delivery profiles showed that the presence of the polymer and the silica delayed release of the antioxidant into gastric media, thus protecting it and allowing its full delivery to the intestinal fluids to improve the e ectiveness of the antioxidant

Potential Use of Annona Genus Plants Leaf Extracts to Produce Bioactive Transdermal Patches by Supercritical Solvent Impregnation

The objective of the present work was to develop a bioactive transdermal patch functionalized with Annona leaf extracts (ALE) by means of supercritical impregnation technique. The potential of six different Annona leaf extracts (ALE) obtained with the enhanced solvent system formed by carbon dioxide + ethanol/acetone was evaluated taking into account the antioxidant activity, total phenol composition and global extraction yields. For the impregnation of ALE, two drug supporting systems were tested: hydrocolloid sodium carboxymethyl cellulose (NaCMC) and polyester dressings (PD). The effect of the impregnation conditions, including pressure (P), temperature (T), percent of co-solvent (ethanol) and ALE/polymer mass ratio, was determined with regard to the loading and the functional activity of the impregnated samples. The optimal impregnation conditions of ALE were established at 55 degrees C and 300 bar which led to obtained transdermal patches with antioxidant and antimicrobial capacity. In order to understand the behavior of the process, the homogeneity of the samples in the vessels was also evaluated. The best results were obtained at higher proportions of co-solvent in the system.The authors would like to thank the research group in "The Institute for Mediterranean and Subtropical Horticulture La Mayora (IHSM)" (CSIC, Malaga, Spain) for providing the raw material and for their support. This research was funded by Junta de Andalucia-FEDER funds 2014-2020, project P18-RT-3272, the Spanish Ministry of Science and Technology, project CTQ2017-86661-R and the European Regional Development Fund(ERDF)

Class-modeling analysis reveals T-cell homeostasis disturbances involved in loss of immune control in elite controllers

Despite long-lasting HIV replication control, a significant proportion of elite controller (EC) patients may experience CD4 T-cell loss. Discovering perturbations in immunological parameters could help our understanding of the mechanisms that may be operating in those patients experiencing loss of immunological control. Methods A case–control study was performed to evaluate if alterations in different T-cell homeostatic parameters can predict CD4 T-cell loss in ECs by comparing data from EC patients showing significant CD4 decline (cases) and EC patients showing stable CD4 counts (controls). The partial least-squares–class modeling (PLS-CM) statistical methodology was employed to discriminate between the two groups of patients, and as a predictive model. Results Herein, we show that among T-cell homeostatic alterations, lower levels of naïve and recent thymic emigrant subsets of CD8 cells and higher levels of effector and senescent subsets of CD8 cells as well as higher levels of exhaustion of CD4 cells, measured prior to CD4 T-cell loss, predict the loss of immunological control. Conclusions These data indicate that the parameters of T-cell homeostasis may identify those EC patients with a higher proclivity to CD4 T-cell loss. Our results may open new avenues for understanding the mechanisms underlying immunological progression despite HIV replication control, and eventually, for finding a functional cure through immune-based clinical trials.projects RD12/0017/0031, RD16/0025/ 0013, and SAF2015-66193-R as part of the Health Research and Development Strategy, State Plan for Scientific and Technical Research and Innovation (2008– 2011 and 2013–2016) and cofinanced by the Institute of Health Carlos III (ISCIII), Sub-Directorate General for Research Assessment and Promotion and European Regional Development Fund. NR is a Miguel Servet investigator from the ISCIII (CP14/00198), Madrid, Spain. C Restrepo was funded by project RD12/0017/ 0031 and is currently funded by project RD16/0025/0013. M García is a predoctoral student co-funded by grant CP14/00198 and an Intramural Research Scholarship from Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD)

VIII Encuentro de Docentes e Investigadores en Historia del Diseño, la Arquitectura y la Ciudad

Acta de congresoLa conmemoración de los cien años de la Reforma Universitaria de 1918 se presentó como una ocasión propicia para debatir el rol de la historia, la teoría y la crítica en la formación y en la práctica profesional de diseñadores, arquitectos y urbanistas. En ese marco el VIII Encuentro de Docentes e Investigadores en Historia del Diseño, la Arquitectura y la Ciudad constituyó un espacio de intercambio y reflexión cuya realización ha sido posible gracias a la colaboración entre Facultades de Arquitectura, Urbanismo y Diseño de la Universidad Nacional y la Facultad de Arquitectura de la Universidad Católica de Córdoba, contando además con la activa participación de mayoría de las Facultades, Centros e Institutos de Historia de la Arquitectura del país y la región. Orientado en su convocatoria tanto a docentes como a estudiantes de Arquitectura y Diseño Industrial de todos los niveles de la FAUD-UNC promovió el debate de ideas a partir de experiencias concretas en instancias tales como mesas temáticas de carácter interdisciplinario, que adoptaron la modalidad de presentación de ponencias, entre otras actividades. En el ámbito de VIII Encuentro, desarrollado en la sede Ciudad Universitaria de Córdoba, se desplegaron numerosas posiciones sobre la enseñanza, la investigación y la formación en historia, teoría y crítica del diseño, la arquitectura y la ciudad; sumándose el aporte realizado a través de sus respectivas conferencias de Ana Clarisa Agüero, Bibiana Cicutti, Fernando Aliata y Alberto Petrina. El conjunto de ponencias que se publican en este Repositorio de la UNC son el resultado de dos intensas jornadas de exposiciones, cuyos contenidos han posibilitado actualizar viejos dilemas y promover nuevos debates. El evento recibió el apoyo de las autoridades de la FAUD-UNC, en especial de la Secretaría de Investigación y de la Biblioteca de nuestra casa, como así también de la Facultad de Arquitectura de la UCC; va para todos ellos un especial agradecimiento

Procesing Naproxen with supercritical CO2

El naproxeno se ha procesado con fluidos supercríticos para mejorar la tasa de disolución y la biodisponibilidad. Las micropartículas de naproxeno se han obtenido mediante un proceso de Expansión Rápida de Soluciones Supercríticas (RESS) en el que se ha utilizado dióxido de carbono como solvente y metanol como cosolvente. También se ha investigado la influencia de la presión de extracción (200-300 bar) y la temperatura de extracción (60 C y 100 C) sobre la precipitación de naproxeno. En general, la morfología de las partículas precipitadas mejoró y el tamaño de las partículas (PS) disminuyó en comparación con la materia prima. Una presión de extracción más baja y una temperatura de extracción más alta llevaron a un tamaño de partícula más pequeño. Por otro lado, se ha aplicado un proceso supercrítico antisolvente (SAS) debido a los valores relativos de solubilidad media del naproxeno en dióxido de carbono supercrítico, con precipitación obtenida con éxito en todos los casos. Se han analizado tanto la concentración inicial de la solución como el efecto disolvente. Se han analizado morfologías y rangos de diámetro medio mediante microscopia electrónica de barrido (SEM) y se ha evaluado la influencia sobre la cristalinidad de ambos procesos supercríticos mediante mediciones de difracción de rayos X (DRX)Naproxen has been processed with supercritical fluids in order to improve the dissolution rate and bioavailability. Microparticles of naproxen have been obtained by a Rapid Expansion of Supercritical Solutions (RESS) process in which carbon dioxide has been used as a solvent and methanol as a cosolvent. The influence of extraction pressure (200–300 bar) and extraction temperature (60 ◦C and 100 ◦C) on the naproxen precipitation has also been investigated. In general, the morphology of the precipitated particles improved and particle size (PS) decreased in comparison to the raw material. Lower extraction pressure and higher extraction temperature led to a smaller particle size. On the other hand, a supercritical antisolvent (SAS) process has been applied due to the relative medium solubility values of naproxen in supercritical carbon dioxide, with precipitation obtained successfully in all cases. The initial concentration of the solution and the solvent effect has both been analysed. Morphologies and mean diameter ranges have been analysed by scanning electron microscopy (SEM) and the influence on crystallinity of both supercritical processes has been evaluated by X-ray diffraction (XRD) measurement

Remoción de arsénico en localidades de la provincia de Santiago del Estero, Argentina: Evaluación del acceso, uso y calidad de agua en poblaciones rurales con problemas de arsénico

Se realizó un trabajo sobre remoción de arsénico y provisión de agua segura en localidades rurales de dos zonas de la provincia de Santiago del Estero, Argentina: una cercana a la capital, en el Departamento Banda y otra al norte, en el Departamento Copo. El trabajo estuvo a cargo de un grupo transdisciplinario formado por investigadores de las ciencias químicas y las ciencias sociales. Un diagnóstico sobre acceso, usos y calidad de agua, que incluyó entrevistas en la población con respecto al acceso al agua segura, indicó que la zona al norte presentaba graves problemas en la calidad del agua de consumo, agravados por difíciles condiciones socioeconómicas; mientras que en la zona de Banda, las aguas no presentaron contaminación microbiológica ni altos niveles de arsénico. Se tomaron muestras de agua de las distintas poblaciones y se caracterizaron fisicoquímicamente. En las que se consideró necesaria la remoción de arsénico, se evaluó la capacidad de algunos materiales económicos con vías al diseño de dispositivos útiles para las poblaciones afectadas. En regiones similares podrían realizarse réplicas de este proyecto.A joint work was performed by a transdisciplinary group involving chemical and social scientists about arsenic removal and provision of safe water in two rural localities of the Santiago del Estero province, Argentina, one close to the capital, in the Banda Department and another one in the north, in the Copo Department. A diagnosis about access, uses and water quality, including interviews to the population with respect to the access to safe water, indicated that the northern zone presented serious problems in the quality of water for human consumption, deepened by difficult socioeconomic conditions, whereas in the Banda zone, the waters presented neither microbiological contamination nor high arsenic levels. Samples of water were taken in the different localities, their properties were measured and, in the samples containing the highest arsenic levels, the capability of some low-cost materials for arsenic removal were evaluated envisaging the design of useful devices for the affected localities. Further replicates of this project can be performed in similar regions.Fil: Litter, Marta Irene. Universidad Nacional de San Martín; Argentina. Comisión Nacional de Energia Atomica. Gerencia D/area de Seguridad Nuclear y Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pereyra, Sebastian. Universidad Nacional de San Martín. Instituto de Altos Estudios Sociales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: López Pasquali, Clara E.. Universidad Nacional de Educación a Distancia; España. Universidad Nacional de Santiago del Estero; ArgentinaFil: Iriel, Analia. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Senn, Alejandro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro; ArgentinaFil: García, Fabiana Elena. Comisión Nacional de Energía Atómica; ArgentinaFil: Blanco Esmoris, María Florencia. Universidad Nacional de San Martín; Argentina. Sistema Federal de Medición de Audiencia; ArgentinaFil: Rondano, Karina del Valle. Universidad Nacional de Santiago del Estero; Argentina. Universidad Nacional de Educación a Distancia; EspañaFil: Pabón Reyes, Deisy Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Dicelio, Lelia Elina. Universidad de Buenos Aires; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Lagorio, María Gabriela. Universidad de Buenos Aires; Argentina. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Noel, Gabriel David. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Instituto de Altos Estudios Sociales; Argentin