Biorefinery of biomass of agro-Industrial banana waste to obtain high-value biopolymers

On a worldwide scale, food demand is increasing as a consequence of global population growth. This makes companies push their food supply chains’ limits with a consequent increase in generation of large amounts of untreated waste that are considered of no value to them. Biorefinery technologies offer a suitable alternative for obtaining high-value products by using unconventional raw materials, such as agro-industrial waste. Currently, most biorefineries aim to take advantage of specific residues (by either chemical, biotechnological, or physical treatments) provided by agro-industry in order to develop high-value products for either in-house use or for sale purposes. This article reviews the currently explored possibilities to apply biorefinery-known processes to banana agro-industrial waste in order to generate high-value products out of this residual biomass source. Firstly, the Central and Latin American context regarding biomass and banana residues is presented, followed by advantages of using banana residues as raw materials for the production of distinct biofuels, nanocellulose fibers, different bioplastics, and other high-value products Lastly, additional uses of banana biomass residues are presented, including energy generation and water treatmen

Conjugados poliméricos y su utilización como nanomedicinas anticancerígenas

Independientemente del descubrimiento de nuevos fármacos para dianas farmacológicas bien establecidas, el compromiso de la ciencia con la sociedad demanda del desarrollo de análogos macromoleculares que mejoren las posibilidades terapéuticas de los fármacos existentes aportando una mayor actividad biológica y una mayor especificidad. Se postula, cada vez con más fuerza, que la aplicación de la nanotecnología a la medicina es la clave para conseguir las mejoras necesarias tanto en diagnosis como en terapia anticancerígeno [1]. Para poder distinguirlos de otros productos biotecnológicos como proteínas y anticuerpos, los nanofármacos han sido definidos como “... sistemas complejos de escala nanométrica constituidos al menos por dos componentes, siendo uno de ellos el agente bioactivo...” [2]. Con varios conjugados polímero-proteína en el mercado y más de 11 conjugados polímero-fármaco en fase clínica, los polímeros terapéuticos pueden ser considerados como una de las primeras nanomedicinas poliméricas [3]. Es importante mencionar que aunque este artículo se centra en el uso de conjugados poliméricos como anticancerígenos, su aplicación clínica es mucho más amplia habiendo sido descritos como posibles inmunomoduladores, agentes antivíricos o fármacos para reconstitución enzimát ica entre otros [3].Independently of the discovery of new drugs for good established pharmacologic targets, the commitment of science with the society demands the development of macromolecular analogs, in order to improve the therapeutic possibilities of existing drugs, contributing to an increase on their biological activity and a greater specificity. Every time becomes more strongly the postulated that the application of nanotechnology in medicine is the key to obtain the necessary improvements in diagnosis and anticancer therapy [1]. In order to distinguish them from the other biotechnological products, such as proteins and antibodies; the nanodrugs have been defined as “… complex systems of nanometric scale, at least constituted by two components, being one of them a bioactive agent…” [2]. With several polymer-protein conjugates in the market and more than eleven polymer-drug conjugates in clinical trails; polymer therapeutics can be considered as the first polymeric nanomedicines [3]. It is important to make clear that although this article is focused on the use of polymeric conjugates as anticancerigenic agents, its clinical application is wider than. Other potential applications have been described for these nanomedicines, such as inmunomodulation, antiviral agents or drugs for enzymatic reconstruction, among others [3][email protected]

Effects of heat on seven endodontic sealers

Purpose: To examine the microscopic surface features, chemical composi-tion, and thermodynamic profile of seven endodontic sealers (AH Plus, Adseal, MTA-Fillapex, RoekoSeal, GuttaFlow 2, GuttaFlow BioSeal, and EndoRez) exposed to high-temperature changes using an endodontic obturation device. Methods: The thermal properties were examined using scanning calorim-etry (DSC) and thermogravimetric analysis (TGA). Then, six disc-shaped specimens of each sealer were prepared and divided into two groups – a room temperature group and a heat exposure group – for analysis of surface and chemical changes using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Results: DSC analysis showed that AH Plus had the highest exothermal signal (122.9°C), while TGA analysis showed that MTA-Fillapex was most affected by increased temperature (32.4% mass loss at 230ºC). SEM analysis showed that while AH Plus and GuttaFlow BioSeal maintained their surface integrity after heat exposure, the EDS profiles demonstrated changes in the chemical composition of the sealers after heat exposure for 5 s. High-temperature exposure had a negative impact on the properties of five of the sealers (Adseal, MTA-Fillapex, RoekoSeal, GuttaFlow 2, and EndoRez). Conclusion: AH Plus and GuttaFlow BioSeal showed minimal changes upon high-temperature exposure, suggesting their suitability for thermal endodontic obturation techniques

Materiales poliméricos compuestos con polietileno (PEBD) y fibras del árbol Maclura tinctoria (Moraceae)

Costa Rica has extensive areas of tropical forests that, managed with care and knowledge, can provide renewable raw materials and conserve biodiversity. Here we characterize the branches, leaves and bark of the “Mora Tree”, Maclura tinctoria. We manufactured composite polymeric materials and applied infrared spectrometry, liquid chromatography, optical microscopy, and the analysis of thermal and mechanical properties. We found polyphenols in all parts of the tree. The natural substrate increases crystallization temperature and reduces the crystallinity of low density polyethylene (LDPE). The elasticity modulus is higher for the composite material than for the LDPE. The fibers of this species are a promissing alternative for new products and to reduce the environmental impact of traditional polymeric materials.Costa Rica cuenta con extensas áreas de bosques tropicales, las cuales deben ser manejadas con cuidado y con el conocimiento adecuado, para lograr conservar la biodiversidad y proporcionar materias primas renovables. En esta investigación caracterizamos las ramas, las hojas y la corteza de  Maclura tinctoria o popularmente conocido como el “árbol de mora”. Se fabricaron materiales poliméricos compuestos, posteriormente se aplicó espectrometría de infrarrojos, cromatografía de líquidos, microscopía óptica y se realizo el análisis de las propiedades térmicas y mecánicas de los materiales. Encontramos polifenoles en todas las partes del árbol. El sustrato natural aumenta la temperatura de cristalización y reduce la cristalinidad del polietileno de baja densidad (LDPE). El módulo de elasticidad es más alta para el material compuesto que para el LDPE. Las fibras de esta especie son una alternativa prometedora para los nuevos productos y para reducir el impacto ambiental de los materiales poliméricos tradicionales

Cholic acid covalently bound to multi-walled carbon nanotubes: Improvements on dispersion stability

Despite the vast volume of literature regarding the interaction between carbon nanotubes and surfactants, the effect of the covalent attachment of an amphiphilic surfactant based on a biomimetic approach to multiwalled carbon nanotubes (MWCNT) has not been explored. In this report, the functionalization of the MWCNT surface with cholic acid by a chemical route is described. A three-step MWCNT chemical modification route was carried out and the properties of the intermediate and final materials were evaluated employing X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM),atomic force microscopy (AFM) and zeta potential measurements. After functionalization, the MWCNT showed a facial bio-amphiphilic behavior; improving the dispersion stability as compared to commercial and oxidized MWCNT. The resulting material preserved the pristine multi-walled structure and originated surprisingly stable dispersions in aqueous and organic polar and low-polarity solvents

Materiales poliméricos compuestos con polietileno (PEBD) y fibras del árbol Maclura tinctoria (Moraceae)

Costa Rica has extensive areas of tropical forests that, managed with care and knowledge, can provide renewable raw materials and conserve biodiversity. Here we characterize the branches, leaves and bark of the “Mora Tree”, Maclura tinctoria. We manufactured composite polymeric materials and applied infrared spectrometry, liquid chromatography, optical microscopy, and the analysis of thermal and mechanical properties. We found polyphenols in all parts of the tree. The natural substrate increases crystallization temperature and reduces the crystallinity of low density polyethylene (LDPE). The elasticity modulus is higher for the composite material than for the LDPE. The fibers of this species are a promissing alternative for new products and to reduce the environmental impact of traditional polymeric materials.Costa Rica cuenta con extensas áreas de bosques tropicales, las cuales deben ser manejadas con cuidado y con el conocimiento adecuado, para lograr conservar la biodiversidad y proporcionar materias primas renovables. En esta investigación caracterizamos las ramas, las hojas y la corteza de  Maclura tinctoria o popularmente conocido como el “árbol de mora”. Se fabricaron materiales poliméricos compuestos, posteriormente se aplicó espectrometría de infrarrojos, cromatografía de líquidos, microscopía óptica y se realizo el análisis de las propiedades térmicas y mecánicas de los materiales. Encontramos polifenoles en todas las partes del árbol. El sustrato natural aumenta la temperatura de cristalización y reduce la cristalinidad del polietileno de baja densidad (LDPE). El módulo de elasticidad es más alta para el material compuesto que para el LDPE. Las fibras de esta especie son una alternativa prometedora para los nuevos productos y para reducir el impacto ambiental de los materiales poliméricos tradicionales

Cholic acid covalently bound to multi-walled carbon nanotubes: Improvements on dispersion stability

Despite the vast volume of literature regarding the interaction between carbon nanotubes and surfactants, the effect of the covalent attachment of an amphiphilic surfactant based on a biomimetic approach to multiwalled carbon nanotubes (MWCNT) has not been explored. In this report, the functionalization of the MWCNT surface with cholic acid by a chemical route is described. A three-step MWCNT chemical modification route was carried out and the properties of the intermediate and final materials were evaluated employing X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM),atomic force microscopy (AFM) and zeta potential measurements. After functionalization, the MWCNT showed a facial bio-amphiphilic behavior; improving the dispersion stability as compared to commercial and oxidized MWCNT. The resulting material preserved the pristine multi-walled structure and originated surprisingly stable dispersions in aqueous and organic polar and low-polarity solvents

Self-assembly study of type I collagen extracted from male Wistar Hannover rat tail tendons

Se seleccionó la licencia Creative Commons para este envío. El documento trae lo siguiente: © The Author(s). 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. (En caso de duda consultar a Meilyn Garro).Background: Collagen, the most abundant protein in the animal kingdom, represents a promising biomaterial for regenerative medicine applications due to its structural diversity and self-assembling complexity. Despite collagen’s widely known structural and functional features, the thermodynamics behind its fibrillogenic self-assembling process is still to be fully understood. In this work we report on a series of spectroscopic, mechanical, morphological and thermodynamic characterizations of high purity type I collagen (with a D-pattern of 65 nm) extracted from Wistar Hannover rat tail. Our herein reported results can be of help to elucidate differences in selfassembly states of proteins using ITC to improve the design of energy responsive and dynamic materials for applications in tissue engineering and regenerative medicine. Methods: Herein we report the systematic study on the self-assembling fibrillogenesis mechanism of type I collagen, we provide morphological and thermodynamic evidence associated to different self-assembly events using ITC titrations. We provide thorough characterization of the effect of pH, effect of salts and protein conformation on self-assembled collagen samples via several complementary biophysical techniques, including circular dichroism (CD), Fourier Transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), atomic force microscopy (AFM), scanning electron microscopy (SEM), dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). Results: Emphasis was made on the use of isothermal titration calorimetry (ITC) for the thermodynamic monitoring of fibrillogenesis stages of the protein. An overall self-assembly enthalpy value of 3.27 ± 0.85 J/mol was found. Different stages of the self-assembly mechanism were identified, initial stages take place at pH values lower than the protein isoelectric point (pI), however, higher energy release events were recorded at collagen’s pI. Denatured collagen employed as a control exhibited higher energy absorption at its pI, suggesting different energy exchange mechanisms as a consequence of different aggregation routesAntecedentes: el colágeno, la proteína más abundante en el reino animal, representa un biomaterial prometedor para aplicaciones de medicina regenerativa debido a su diversidad estructural y complejidad de autoensamblaje. A pesar de las características estructurales y funcionales ampliamente conocidas del colágeno, la termodinámica detrás de su proceso de autoensamblaje fibrilogénico aún debe entenderse completamente. En este trabajo informamos sobre una serie de caracterizaciones espectroscópicas, mecánicas, morfológicas y termodinámicas de colágeno tipo I de alta pureza (con un patrón D de 65 nm) extraído de la cola de rata Wistar Hannover. Nuestros resultados aquí reportados pueden ayudar a dilucidar las diferencias en los estados de autoensamblaje de proteínas usando ITC para mejorar el diseño de materiales dinámicos y sensibles a la energía para aplicaciones en ingeniería de tejidos y medicina regenerativa. Métodos: A continuación presentamos el estudio sistemático sobre el mecanismo de fibrilogénesis autoensamblante del colágeno tipo I, aportamos evidencia morfológica y termodinámica asociada a diferentes eventos de autoensamblaje mediante titulaciones ITC. Proporcionamos una caracterización completa del efecto del pH, el efecto de las sales y la conformación de proteínas en muestras de colágeno autoensambladas a través de varias técnicas biofísicas complementarias, que incluyen dicroísmo circular (CD), espectroscopía infrarroja por transformada de Fourier (FTIR), calorimetría diferencial de barrido (DSC), microscopía de fuerza atómica (AFM), microscopía electrónica de barrido (SEM), análisis térmico mecánico dinámico (DMTA) y análisis termogravimétrico (TGA). Resultados: Se hizo énfasis en el uso de calorimetría de titulación isotérmica (ITC) para el monitoreo termodinámico de las etapas de fibrilogénesis de la proteína. Se encontró un valor de entalpía de autoensamblaje general de 3,27 ± 0,85 J / mol. Se identificaron diferentes etapas del mecanismo de autoensamblaje, las etapas iniciales tienen lugar a valores de pH más bajos que el punto isoeléctrico de la proteína (pI), sin embargo, se registraron eventos de liberación de energía más altos en el pI del colágeno. El colágeno desnaturalizado empleado como control exhibió una mayor absorción de energía en su pI, lo que sugiere diferentes mecanismos de intercambio de energía como consecuencia de diferentes rutas de agregación.Instituto Tecnológico de Costa Rica, Costa RicaUniversidad SEK Chile, ChileUniversidad de Costa Rica, Costa RicaCentro Nacional de Alta Tecnología, Costa RicaUniversidad Nacional, Costa RicaEscuela de Químic

Crystal Forms of the Antihypertensive Drug Irbesartan: A Crystallographic, Spectroscopic, and Hirshfeld Surface Analysis Investigation.

The design of new pharmaceutical solids with improved physical and chemical properties can be reached through in-detail knowledge of the noncovalent intermolecular interactions between the molecules in the context of crystal packing. Although crystallization from solutions is well-known for obtaining new solids, the effect of some variables on crystallization is not yet thoroughly understood. Among these variables, solvents are noteworthy. In this context, the present study aimed to investigate the effect of ethanol (EtOH), acetonitrile (MeCN), and acetone (ACTN) on obtaining irbesartan (IBS) crystal forms with 2,3-dibromosuccinic acid. Crystal structures were solved by single-crystal diffraction, and the intermolecular interactions were analyzed using the Hirshfeld surfaces analysis. The characterization of physicochemical properties was carried out by powder X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), thermal analysis, and solution-state NMR techniques. Two different IBS salts were obtained, one from MeCN and ACTN (compound 1) and a different one from EtOH (compound 2). The experimental results were in agreement with the findings obtained through quantum mechanics continuum solvation models. Compound 1 crystallized as a monoclinic system P21/c, whereas compound 2 in a triclinic system P1̅. In both structures, a net of strong hydrogen bonds is present, and their existence was confirmed by the FT-IR results. In addition, the IBS cation acts as a H-bond donor through the N1 and N6 nitrogen atoms which interact with the bromide anion and the water molecule O1W in compound 1. Meanwhile, N1 and N6 nitrogen atoms interact with the oxygen atoms provided by two symmetry-related 2,3-dibromo succinate anions in compound 2. Solution-state NMR data agreed with the protonation of the imidazolone ring in the crystal structure of compound 1. Both salts presented a different thermal behavior not only in melting temperature but also in thermal stability