Search

Nanocellulose (NC) has a wide variety of emerging applications, including enzyme immobilization, drug delivery, and imaging diagnosis. On the other hand, derivatives of hydrazinonicotinic acid (HYNIC) have been used as coordination-agents for their binding to 99mTc in the development of potential radiopharmaceuticals. To this end, we studied and developed NC-HYNIC-99mTc for diagnostic imaging using NC obtained from rice husk using Trichoderma reseii and Phanaerochaete chrysosporium in a semi-solid fermentation system to generate a potential nanoradiopharmaceutical agent. In this work, we performed the separation of nanosilica, microcellulose, and nanocellulose using the TAPPI T203 os-74 technique. The synthesis of conjugate NC-HYNIC was performed following a one-pot procedure. The NC and the conjugate NC-HYNIC were characterized by Fourier Transform Infrared Spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and atomic force microscopy (AFM). We obtained NC with a structure of laminar-like nanofibers. The yield of NC was 55% and the conjugate NC-HYNIC was obtained with a yield of 36%. The TGA and FTIR analyses showed that the NC functionalized with HYNIC had similar characteristics to those of NC. In addition, the AFM analysis of the functionalized NC showed an average height of 8 ± 3 nm, while the NC showed an average height of 10 ± 4 nm. The subsequent binding to 99mTc was assayed, and the purity of the radiolabeled product and the efficiency of the process was studied by ITLC chromatography. The radiolabeling process was very efficient with a radiochemical purity of 98 ± 1.2%, which opens the possibility of a new potential-imaging agent.

The objective of the research was to disseminate nanotechnology concepts, applications, and benefits among educators from different Costa Rican provinces to increase their acceptance and dissemination of the subject to elementary students. Teachers from different areas of the country were called to participate. Five training workshops were held in Turrialba, Cahuita, Alajuela, Buenos Aires, and Nicoya covering fundamental nanotechnology concepts and applications, as well as the contributions offered from an educational point of view. The workshops were held in person two full days including talks, practical activities, and discussions. In addition, educational materials were prepared, such as a poster and an information brochure, and two educational videos on nanotechnology. A total of 98 teachers, 87% men and 13% women, from different provinces were trained. Workshop evaluations were positive in terms of the knowledge acquired with an average of 57.30%, compared to 5.10% before starting the training. This project contributed to strengthen teachers’ knowledge about nanotechnology and its applications. In addition, national and international nanotechnology research projects were made known. The above will help teachers disseminate new knowledge to the student population, thus becoming knowledge multipliers. El objetivo de la investigación fue socializar los conceptos, aplicaciones y beneficios de la nanotecnología entre personal educador de las diferentes provincias de Costa Rica, para incrementar su aceptación y difusión del tema a los niños y niñas de educación primaria. Se realizó una convocatoria para seleccionar a sujetos educadores de distintas zonas del país. Se impartieron 5 talleres de capacitación en las siguientes localidades: Turrialba, Cahuita, Alajuela, Buenos Aires y Nicoya. En estos se abordaron temas fundamentales de la nanotecnología y sus aplicaciones, así como los aportes que se pueden ofrecer desde el punto de vista educativo. Los talleres se impartieron de manera presencial durante dos días completos, con exposición de charlas, actividades prácticas y discusiones. Además, se preparó material didáctico, como un afiche y un folleto informativo, y dos videos educativos alusivos a la nanotecnología. Se logró capacitar a 98 sujetos educadores, 87 % hombres y 13 % mujeres, de distintas provincias del país. Los resultados de las evaluaciones de los talleres fueron buenos, en términos del conocimiento adquirido con un promedio de calificación de un 57,30 %, comparado con un 5,10 % alcanzado antes de iniciar la capacitación. Este proyecto, contribuyó a fortalecer el conocimiento de los educadores sobre la nanotecnología y sus aplicaciones; además, se dieron a conocer proyectos de investigación nacionales e internacionales relativos a la nanotecnología. Lo anterior permitirá que los educadores sean capaces de transmitir los nuevos conocimientos a la población estudiantil, y se conviertan en multiplicadores del conocimiento. Esta pesquisa teve como objetivo socializar os conceitos, aplicações e benefícios da nanotecnologia entre os educadores dos diferentes municípios da Costa Rica, para aumentar a aceitação e difusão do tema nos estudantes do ensino fundamental. Foi realizada uma convocatória para escolher sujeitos educadores de distintas zonas do país. Foram ministradas 5 oficinas de capacitação nas seguintes localidades: Turrialba, Cahuita, Alajuela, Buenos Aires e Nicoya. Foram abordados temas fundamentais da nanotecnologia e suas aplicações, assim como as contribuições que podem ser dadas desde o ponto de vista educativo. Essas oficinas foram ministradas presencialmente durante dois dias completos, com exposição de palestras, atividades práticas e discussões. Além disso, foi preparado material didático, como um cartaz e um folheto informativo, e dois vídeos educativos alusivos à nanotecnologia. Foi possível capacitar 98 sujeitos educadores, 87 % homens e 13 % mulheres, de distintos municípios do país. Os resultados das avaliações das oficinas foram bons, em termos do conhecimento adquirido com uma média de nota de 57,30 %, comparado aos 5,10 % alcançados antes de iniciar a capacitação. Este projeto contribuiu para a consolidação do conhecimento dos educadores sobre a nanotecnologia e suas aplicações; além disso, divulgaram projetos de pesquisas nacionais e internacionais relativos à nanotecnologia. Isso permitirá que os educadores sejam capazes de transmitir os novos conhecimentos à população estudantil e de se transformar em multiplicadores do conhecimento.

Montes de Oca Vásquez, G. (2021). Impacto de concentraciones ambientalmente relevantes de nanopartículas de plata en la comunidad microbiana del suelo. [Tesis de Doctorado]. Universidad Nacional, Costa Rica. La nanotecnología es un área de la ciencia emergente que involucra la ingeniería de partículas nanométricas de diversos materiales (Khare et al., 2014). De acuerdo con la Agencia de Protección Ambiental de Estados Unidos (EPA, por sus siglas en inglés), la nanotecnología se define como "la creación y uso de estructuras, dispositivos y sistemas que tienen propiedades y funciones novedosas debido a su pequeño tamaño". Estas partículas y estructuras moleculares tienen dimensiones en el rango nanométrico (típicamente entre 1 y 100 nm en al menos una dimensión) (Hobson, 2011). Es debido a esta escala que los materiales pueden adquirir propiedades físicas y químicas diferentes a las que tienen en la escala macroscópica (Ivask et al., 2014; Tortella et al., 2020), como propiedades ópticas, electrónicas, antimicrobianas, magnéticas y catalíticas (Capek, 2006). Debido a estas características la producción global de las nanopartículas (NPs) continúa aumentando, y se han utilizado en numerosos productos comerciales con diversas aplicaciones industriales (Sharma et al., 2019; Tortella et al., 2020). Se han utilizado en el área agrícola, como fertilizantes y pesticidas (Madbouly et al., 2017), en el área médica (Her et al., 2017), principalmente con el desarrollo de NPs para la liberación controlada de fármacos (Pang et al., 2019), en el desarrollo de dispositivos de diagnóstico médico (McNamara & Tofail, 2015), además, de su uso para mejorar las imágenes médicas (Ryan et al., 2019). Asimismo, las NPs se han utilizado en dispositivos electrónicos (Khanra et al., 2018), en cosméticos (de la Calle et al., 2017), en la nanoremediación (Moustafa, 2017), en el sector agroalimentario (Dasgupta et al., 2017), entre otros. Nanotechnology is an emerging area of ​​science that involves the engineering of nanometric particles of various materials (Khare et al., 2014). According to the United States Environmental Protection Agency (EPA), nanotechnology is defined as "the creation and use of structures, devices and systems that have novel properties and functions due to their small size." These particles and molecular structures have dimensions in the nanometric range (typically between 1 and 100 nm in at least one dimension) (Hobson, 2011). It is due to this scale that materials can acquire physical and chemical properties different from those they have on the macroscopic scale (Ivask et al., 2014; Tortella et al., 2020), such as optical, electronic, antimicrobial, magnetic and catalytic properties. (Capek, 2006). Due to these characteristics, the global production of nanoparticles (NPs) continues to increase, and they have been used in numerous commercial products with various industrial applications (Sharma et al., 2019; Tortella et al., 2020). They have been used in the agricultural area, as fertilizers and pesticides (Madbouly et al., 2017), in the medical area (Her et al., 2017), mainly with the development of NPs for the controlled release of drugs (Pang et al. ., 2019), in the development of medical diagnostic devices (McNamara & Tofail, 2015), in addition to their use to improve medical images (Ryan et al., 2019). Likewise, NPs have been used in electronic devices (Khanra et al., 2018), in cosmetics (de la Calle et al., 2017), in nanoremediation (Moustafa, 2017), in the agri-food sector (Dasgupta et al. , 2017), between Universidad Nacional, Costa Rica Departamento de Física