Artículos científicos

URI permanente para esta colecciónhttp://10.0.96.45:4000/handle/11056/14823

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Biodegradable plastics in aquatic ecosystems: latest findings, research gaps, and recommendations
(IOP Publishing (Reino Unido), 2022) Ribba, Laura; Lopretti, Mary; Montes de Oca-Vásquez, Gabriela; Batista, Diego; Goyanes, Silvia; Jose-Roberto, Vega-Baudrit
Abstract. The negative impact of plastic accumulation in aquatic ecosystems is a known and undeniable problem. However, while many of the scientific community’s countermeasures against such accumulation target the effects of the most common commodity plastics, the consequences of so-called ‘biodegradable’ plastics in those ecosystems are seldom discussed. After all, though their alleged biodegradability sustains the widespread belief that they are harmless to the environment, because a material’s fate determines its classification as biodegradable or not, many plastics classified as biodegradable do not in fact meet the required norms and standards of biodegradability in aquatic ecosystems. Furthermore, during the past five years, the scientific community has shown that the degradation of such plastics can generate bio-microplastics that have effects similar to or worse than those of conventional microplastics (MPs). Against that background, this review details the latest findings regarding how biodegradable plastics can influence aquatic ecosystems and thus cause adverse health effects in living organisms and/or act as vectors of chemical pollutants. Beyond that, it identifies the key aspects of such trends to be investigated in greater depth, including the need to consider a wider variety of biodegradable plastics and to develop systematic methods that allow quantifying and identifying the remains of those pollutants in living species. Other aspects worth considering include the arrival and mobilisation dynamics of MPs in oceans. The ways in which small animals fed by filtering (e.g. red crabs and other zooplankton organisms) move MPs through the water column and into food webs also merit attention, for those MPs are ingested by numerous species at different trophic levels, at which point bioaccumulation in tissues has to be considered as a factor of toxicity. This review closes with a series of recommendations and perspectives for future studies on biodegradable plastics in aquatic ecosystems.
Tracing Groundwater-Surface Water Interactions in a Volcanic Maar Lake Using Stable Isotopes and 222Rn
(Universidad Nacional Costa Rica, 2024-12-09) Esquivel Hernández, Germain; Montealegre Viales, Emanuel; Sánchez‐Gutiérrez, Rolando; Villalobos‐Forbes, Mario; Pérez‐Salazar, Roy; Sánchez‐Murillo, Ricardo; Mena‐Rivera, Leonardo; Birkel, Christian; Ortega, Lucía
Isotope hydrological studies to understand groundwater-surface water interactions in tropical, high-elevation catchments are limited. These interactions are important in controlling lake water residence time, aqueous biogeochemistry, and water availability for downstream communities and ecosystems. To better comprehend the complexity of spatio-temporal variations in the aquifer-lake domain in tropical volcanic regions, a multi-tracer approach including water and inorganic carbon stable isotopes (δ2H, δ18O, δ13CDIC), hydrochemistry, and 222Rn was applied in Lake Hule, northern Costa Rica. Seasonal isotope mass balance calculations using lake, stream, precipitation, and groundwater compositions were supplemented with local hydrometeorological information. Evaporation to inflow ratios (E/I) revealed a small variability between the dry (December–April) and wet seasons (May–November), with relatively low evaporation losses, 2.9 ± 1.0 % and 3.2 ± 1.8 %, respectively. Bayesian end-member analysis indicated that annual inputs from groundwater, precipitation, and runoff represented 61.3 ± 8.1%, 24.4 ± 8.4, and 14.3 ± 5.9% of total lake inflow, respectively. Temporal variations of δ13CDIC confirmed the key role volcanic carbonate buffering plays in this lake and indicated greater CO2 degassing from groundwater sources in the wet season. This tracer-aided assessment in a volcanic lake maar of northern Costa Rica provides evidence of previously unknown groundwater-surface water interactions and illustrates the application of isotopic tools for estimating water balances and seasonal variability of groundwater discharge into natural lakes across the volcanic front of Central America.
Interaction and Compatibility Studies in the Development of Olmesartan Medoxomil and Hydrochlorothiazide Formulations under a Real Manufacturing Process
(Multidisciplinary Digital Publishing Institute (MDPI) (Suiza), 2022) Murillo Fernández, Mac Arturo; Montero Zeledón, Ernesto; Abdala-Saiz, Ariadna; Jose-Roberto, Vega-Baudrit; Araya Sibaja, Andrea Mariela
Abstract. Adrug–drug and drug–excipient interactions and compatibilities studywas conducted for two fixed-dose combination (FDC) products containing olmesartan medoxomil (OLM)/hydrochlorothiazide (HCT) 20/12.5 mg and OLM/HCT 40/12.5 mg during their development including storage. The study consisted of the evaluation of samples retrieved during all stages of a real manufacturing process. Powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetry (TGA), Fourier transform infrared spectroscopy (FT-IR), and contact angle techniques were applied to the samples to determine interactions and incompatibilities. Dissolution tests and long-term stability studies were conducted to evaluate dosage form performance. Results showed weak solid–state interactions able to obtain a eutectic mixture of OLMand HCT while microcrystalline cellulose (MC) impacted the thermal stability of both drugs. Reliable dissolution and long-term stability tests confirmed that the interactions observed were not considered incompatibilities because they were not influenced by the performance of the final products.
Pretreatment methods of lignocellulosic wastes into value-added products: recent advances and possibilities
(Springer (Alemania), 2022) Batista Meneses, Diego; Montes de Oca-Vásquez, Gabriela; Jose-Roberto, Vega-Baudrit; Rojas-Álvarez, Mauricio; Corrales-Castillo, Joshua; Murillo-Araya, Luis C.
Abstract. A number of industries currently produce many tons of agroindustrial wastes with significant consequences on the environment and human and animal health. In recent years, increasing emphasis has been placed on reducing this negative impact. This review article aims to investigate the use of pretreatmentmethods that can be applied as an alternative to the usage of residual biomass. In addition, we seek to highlight the efficiency of the processes as well as possible weaknesses, which are associated with high energy and reagent consumption, low yields, and possible secondary impacts. Generally, the waste chemical composition consists mainly of cellulose, hemicellulose, and lignin; these can be fractionated, extracted, and purified to produce different value-added products, such as biofuels, organic acids, enzymes, biopolymers, and chemical additives. Despite the multiple possibilities to produce different products from lignocellulosic biomass, further research is still required to enhance the efficiency of the methods used nowadays and find new procedures.
Bio-Inspired Proanthocyanidins from Blueberries’ Surface Coating Prevents Red Blood Cell Agglutination on Urinary Silicon-Based Catheters
(Multidisciplinary Digital Publishing Institute (MDPI) (Suiza), 2022) Orozco-Fernández, Viviana; Gómez-Solano, Sofía; Calderón, Jennifer; Jose-Roberto, Vega-Baudrit; Rischka, Klaus; Corrales, Yendry
Abstract. Thrombosis can cause the occlusion of implantable medical devices, leading to the rejection of the device and subsequent mortality. Thrombosis is primarily induced by red blood aggregation and coagulation. The administration of anticoagulant drugs is generally used as a treatment to avoid these processes. Adverse effects such as bleeding in the event of an anticoagulant overdose, osteoporosis associated with prolonged use, hypersensitivity, and hives have been reported. New strategies such as biomolecule surface functionalization have recently been studied to overcome these problems. In this study, we report a novel coating composed of polydopamine (PDA) and proanthocyanidins (PACs) from blueberry extract to avoid red blood aggregation in short-term use medical devices such as silicone catheters. We showed that PDA formed stable films on silicone surfaces and PACs could be immobilized on PDA layers using laccase as a catalyst. The PDA–PACs films decreased surface hydrophilicity, increased surface roughness, and decreased plasma protein adsorption. The films were stable in phosphate buffer saline (PBS) and cell culture media. Furthermore, red blood cell adsorption and aggregation decreased. These effects are attributed to changes in the membrane fluidity that influences adhesion, the steric hindrance of the layers, and the low adsorption of plasma proteins on the PAC layer.
Nanocellulose Extracted from Paraguayan Residual Agro-Industrial Biomass: Extraction Process, Physicochemical and Morphological Characterization
(Multidisciplinary Digital Publishing Institute (MDPI) (Suiza), 2022) Velázquez, María Edelira; Ferreiro Balbuena, Omayra B.; Batista Menezes, Diego; Corrales, Yendry; Jose-Roberto, Vega-Baudrit; RIVALDI CHAVEZ, JUAN DANIEL
Abstract. Residual biomasses from agro-industries in Paraguay, including soybean hulls (SBHs) and sugarcane bagasse (SCB), were studied as a source for nanocellulose extraction for the first time. For that purpose, both biomasses were delignified in a semi-pilot stainless-steel reactor, and the cellulose pulp was subjected to a bleaching process with NaClO (2.5%, w/v). The nanocellulose (CNC) was obtained after two-step acid hydrolysis. Firstly, the bleached cellulose was hydrolyzed with HCl (17%, w/w) for two hours at 60 °C to obtain microcrystals by removing most of the amorphous fraction. The celluloses were then treated with H2SO4 (65%, w/w) at 45 °C for 45 min to obtain nanocellulose. Physicochemical and morphological properties were analyzed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction analysis (XRD). The SBHs nanocellulose had a whisker-like form with a 230 ± 42 nm diameter and a 12 ± 2 nm height, and the SCB nanocellulose had a fibril-like form with a 103 ± 30 nm diameter and a height of 6 ± 3 nm. The nanocellulose from SBHs and SCB had good thermal stability as its degradation temperature started at 250 °C. Furthermore, the nanocellulose obtained was negatively charged and formed stable dispersion in water at 0.1 mg/mL concentration and a pH of around 6.5.
Hybrid Nanoparticles of Proanthocyanidins from Uncaria tomentosa Leaves: QTOF-ESI MS Characterization, Antioxidant Activity and Immune Cellular Response
(Multidisciplinary Digital Publishing Institute (MDPI) (Suiza), 2022) Araya Sibaja, Andrea Mariela; Wilhelm, Krissia; Vargas-Huertas, Felipe; Quiros, Maria Isabel; Alvarado-Corella, Diego; Mora Román, Juan José; Jose-Roberto, Vega-Baudrit; SANCHEZ-KOPPER, ANDRES; Navarro-Hoyos, Mirtha
Abstract. Previous studies in Uncaria tomentosa have shown promising results concerning the characterization of polyphenols with leaves yielding more diverse proanthocyanidins and higher bioactivities values. However, the polyphenols-microbiota interaction at the colonic level and their catabolites avoid the beneficial effects that can be exerted by this medicinal plant when consumed. In this regard, a new generation of hybrid nanoparticles has demonstrated improvements in natural compounds’ activity by increasing their bioavailability. In this line, we report a detailed study of the characterization of a proanthocyanidin-enriched extract (PA-E) from U. tomentosa leaves from Costa Rica using UPLC-QTOF-ESI MS. Moreover, two types of hybrid nanoparticles, a polymeric-lipid (F-1) and a protein-lipid (F-2) loaded with PA-E were synthesized and their characterization was conducted by dynamic light scattering (DLS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FT-IR), high-resolution transmission electron microscopy (HR-TEM), and encapsulation efficiency (%EE). In addition, in vitro release, antioxidant activity through 2,2-diphenyl-1-picrylhidrazyl (DPPH) as well as in vivo delayed-type hypersensitivity (DTH) reaction was evaluated. Results allowed the identification of 50 different compounds. The PA-E loaded nanoparticles F-1 and F-2 achieved encapsulation efficiency of ≥92%. The formulations exhibited porosity and spherical shapes with a size average of 26.1 ± 0.8 and 11.8 ± 3.3 nm for F-1 and F-2, respectively. PA-E increased its release rate from the nanoparticles compared to the free extract in water and antioxidant activity in an aqueous solution. In vivo, the delayed-type hypersensitive test shows the higher immune stimulation of the flavan-3-ols with higher molecular weight from U. tomentosa when administered as a nanoformulation, resulting in augmented antigen-specific responses. The present work constitutes to our knowledge, the first report on these bioactivities for proanthocyanidins from Uncaria tomentosa leaves when administrated by nanosystems, hence, enhancing the cellular response in mice, confirming their role in immune modulation.
Preparation and Characterization of a Novel Nanocellulose‑Derivative as a Potential Radiopharmaceutical Agent
(Springer (Alemania), 2022) Lecot, Nicole; Gandaras, Rosario; Batista‑Menezes, Diego; Montes de Oca-Vásquez, Gabriela; Cabral, Pablo; García, Ma. Fernanda; Jose-Roberto, Vega-Baudrit; Cerecetto, Hugo; Lopretti, Mary
Abstract. 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.
Topical Chitosan-Based Thermo-Responsive Scaffold Provides Dexketoprofen Trometamol Controlled Release for 24 h Use
(Multidisciplinary Digital Publishing Institute (MDPI) (Suiza), 2021) Castillo, Luis; Sanabria-Espinoza, Pablo; Murillo-Castillo, Brayan; Montes de Oca-Vásquez, Gabriela; Batista-Menezes, Diego; Calvo-Guzmán, Briner; Ramírez, Nils; Jose-Roberto, Vega-Baudrit
Chronic and non-healing wounds demand personalized and more effective therapies for treating complications and improving patient compliance. Concerning that, this work aims to develop a suitable chitosan-based thermo-responsive scaffold to provide 24 h controlled release of Dexketoprofen trometamol (DKT). Three formulation prototypes were developed using chitosan (F1), 2:1 chitosan: PVA (F2), and 1:1 chitosan:gelatin (F3). Compatibility tests were done by DSC, TG, and FT-IR. SEM was employed to examine the morphology of the surface and inner layers from the scaffolds. In vitro release studies were performed at 32 °C and 38 °C, and the profiles were later adjusted to different kinetic models for the best formulation. F3 showed the most controlled release of DKT at 32 °C for 24 h (77.75 ± 2.72%) and reduced the burst release in the initial 6 h (40.18 ± 1.00%). The formulation exhibited a lower critical solution temperature (LCST) at 34.96 °C, and due to this phase transition, an increased release was observed at 38 °C (88.52 ± 2.07% at 12 h). The release profile for this formulation fits with Hixson–Crowell and Korsmeyer–Peppas kinetic models at both temperatures. Therefore, the developed scaffold for DKT delivery performs adequate controlled release, thereby; it can potentially overcome adherence issues and complications in wound healing applications.
Use of nanosystems to improve the anticancer effects of curcumin
(Beilstein-Institut zur Förderung der Chemischen Wissenschaften (Alemania), 2021) Araya Sibaja, Andrea Mariela; Salazar-López, Norma Julieta; Wilhelm Romero, Krissia; Jose-Roberto, Vega-Baudrit; Domínguez-Avila, J. Abraham; Velázquez Contreras, Carlos A.; Robles Zepeda, Ramón Enrique; Navarro-Hoyos, Mirtha; González-Aguilar, Gustavo A.
Curcumin (CUR) is a phenolic compound that is safe for human consumption. It exhibits chemopreventive, antiproliferative, antiangiogenic, and antimetastatic effects. However, these benefits can be hampered due to the lipophilic nature, rapid metabolism, low bioavailability, and fast elimination of the molecule. Considering this, the present work reviews the use of CUR-based nanosystems as anticancer agents, including conventional nanosystems (i.e., liposomes, nanoemulsions, nanocrystals, nanosuspensions, polymeric nanoparticles) and nanosystems that respond to external stimuli (i.e., magnetic nanoparticles and photodynamic therapy). Previous studies showed that the effects of CUR were improved when loaded into nanosystems as compared to the free compound, as well as synergist effects when it is co-administrated alongside with other molecules. In order to maximize the beneficial health effects of CUR, critical factors need to be strictly controlled, such as particle size, morphology, and interaction between the encapsulating material and CUR. In addition, there is an area of study to be explored in the development of CUR-based smart materials for nanomedical applications. Imaging-guided drug delivery of CUR-based nanosystems may also directly target specific cells, thereby increasing the therapeutic and chemopreventive efficacy of this versatile compound.
Tropical agroindustrial biowaste revalorization through integrative biorefineries—review part I: coffee and palm oil by-products
(Springer (Alemania), 2023) Mora Villalobos, José Aníbal; Aguilar, Francisco; Carballo Arce, Ana Francis; Jose-Roberto, Vega-Baudrit; Trimino-Vazquez, Humberto; Villegas Peñaranda, Luis Roberto; Stöbener, Anne; Eixenberger, Daniela; Bubenheim, Paul; Sandoval-Barrantes, Manuel; Liese, Andreas
Tropical crops are an important source of wealth in many countries. The current agribusiness model is based on the production of a final commodity, leading to the production of organic by-products (biowastes) that in many cases contain bioactive compounds with a potential added value. The exploitation of these by-products is the foundation of the circular economy that leads to the generation of greener bioprocesses for the industry with foreseeable economic improvements in production systems. This review aims to point out the idle opportunities of agricultural production systems and their associated biowastes to contribute to the establishment of a bioeconomy. Hence, the focus lies on five tropical extensive crops: coffee, oil palm, sugar cane, banana, and pineapple. This first part of the review explores agricultural wastes originated from the coffee and oil palm industrial process and is oriented on the potential use of these by-products as a starting material for the alternative obtention of chemicals, otherwise obtained from petrochemistry. The second part of the review focuses on prospective use of lignocellulosic rich biowaste that is derived from the industrialization of sugar cane, banana, and pineapple. A fundamental difference for the use of coffee biomass compared to other crops is the presence of numerous bioactive compounds that are not yet properly utilized, such as antioxidants (i.e., caffeic acid, chlorogenic acid, ferulic acid), as well as their possible use in the manufacture of products of interest in the cosmetic (i.e., quinic acid) or pharmaceutical industry (i.e., caffeic acid phenethyl ester). In the case of oil palm, its potential lies in obtaining chemicals such as glycerol and carotenoids, or in the bioenergy production.
Tropical agroindustrial biowaste revalorization through integrative biorefineries—review part II: pineapple, sugarcane and banana by‑products in Costa Rica
(Springer (Alemania), 2024) Eixenberger, Daniela; Carballo Arce, Ana Francis; Jose-Roberto, Vega-Baudrit; Trimino‑Vazquez, Humberto; Villegas Peñaranda, Luis Roberto; Stöbener, Anne; Aguilar, Francisco; Mora Villalobos, José Aníbal; Sandoval-Barrantes, Manuel; Bubenheim, Paul; Liese, Andreas
Biorefineries are a model for greener production processes, based on the concept of bioeconomy. Instead of targeting firstgeneration biofuels—that compete with food supply—the focus relies on lignocellulosic material, considering many aspects, such as sustainable fuel production, as well as valorization of waste, as an alternative to the traditional petrochemical approach of goods production. Especially, in tropical countries agricultural activities lead to tremendous amounts of biomass, resulting in waste that has to be dealt with. In the case of Costa Rica, the five major crops cultivated for export are coffee, oil palm, pineapple, sugarcane, and banana. Traditional ways of waste treatment cannot cope with the increasing amount of biomass produced and therefore, bear various challenges often related to increased pollution. This review aims to bring up the recent state of waste treatment but even more, stress potential opportunities of adding value to not used residues; thus, improve sustainability in the agro industrial sector. Part I of the review already highlighted the potential of producing promising bioactive chemical compounds by novel biorefinery concepts from agricultural waste originating from coffee and oil palm cultivation. This second part focuses on the lignocellulose-rich biowaste from pineapple, sugarcane, and banana, showing biorefinery concepts, where fuel and energy production, as well as establishment of novel products and new applications, play an important role.
Evaluación del Efecto del uso de Aditivos de Carbono en las Propiedades Térmicas y Mecánicas de un Material Termoplástico con Potenciales Aplicaciones en el Sector Biomédico y Aeroespacial
(Universidad del País Vasco (España), 2021) Mora Bolaños, Rodrigo José; Chaves Villareal, Claudia; Jose-Roberto, Vega-Baudrit
Resumen. Se realizó un estudio comparativo para evaluar el efecto de agregar nanotubos de carbono multipared (NTCPM) y de fibra de carbono (FC) en las propiedades mecánicas y térmicas, en una resina termoplástica de Acrilonitrilo–Butadieno–Estireno (ABS), con potenciales aplicaciones en los sectores de dispositivos biomédicos y aeroespaciales, de gran auge en Costa Rica. Se empleó ABS comercial con FC al 15%, y se comparó con ABS conteniendo 1 y 0,5% de NTCPM, según se sugiere en la literatura. Se realizaron estudios mediante análisis termogravimétrico (TGA), calorimetría diferencial de barrido (DSC) y análisis térmico dinámico mecánico (DMTA). Los TGA mostraron un mejoramiento en las propiedades térmicas, el ABS sin aditivos mostró una degradación inicial a 320°C, mientras que al estar reforzado con FC lo hizo 370°C y con NTCPM al 0,5% y 1% lo hizo a 340°C. En DSC se mostraron ligeros cambios, poco significativos en la temperatura de transición vítrea (Tg) entre los materiales con aditivos y el material puro. En el DMTA se mostró disminución de propiedades mecánicas al añadir FC, sin embargo, se observó un aumento al agregar nanotubos de carbono. Se concluyó que el impacto obtenido en las propiedades térmicas en ambos aditivos puede ser ventajoso para aplicaciones que requieren cuidados de temperatura en procesamiento, y que las propiedades mecánicas se optimizan con los NTCPM ante mayor porcentaje agregado debido a la buena adhesión de los nanotubos a la matriz de ABS.
Hidrogeles Híbridos de Quitosano y Polietilenglicol (QUIT:PEG) para Potenciales Aplicaciones Biomédicas
(Universidad del País Vasco (España), 2021) Elizondo Castillo, Hellen; Madrigal-Carballo, Sergio; ESQUIVEL, MARIANELLY; Lopretti, Mary; Jose-Roberto, Vega-Baudrit
Resumen. En este trabajo se sintetizaron hidrogeles híbridos de quitosano y polietilenglicol (QUIT:PEG) utilizando PEG de diferentes masas moleculares y en proporciones variadas, con el objetivo de determinar las condiciones de formulación óptimas para obtener la mejor relación entre la matriz y el entrecruzante. Las pruebas de caracterización de los hidrogeles formulados, permitieron comprobar la eficacia del proceso de modificación de la matriz polimérica de quitosano, mediante la adición de polietilenglicol. Los ensayos permiten concluir que se produce un efecto entrecruzante de tipo físico sobre la matriz polimérica bidimensional de los hidrogeles de quitosano, al interaccionar con el polietilenglicol. Conforme se adicionó entrecruzante a la matriz, el hidrogel se tornó más estable al entrar en contacto con líquidos, esto demostrado por su capacidad de hinchamiento y menor degradación, comparado al hidrogel sin modificar, se determinó que el sistema 90:10, es el más adecuado para ensayos de aplicabilidad biomédica. Los ensayos de esterilización de las matrices híbridas mediante irradiación ultravioleta, no presentaron ningún efecto significativo sobre las propiedades físicas y químicas del biomaterial. Adicionalmente este proceso de esterilización permitió eliminar de forma efectiva hasta un 100% el crecimiento de las bacterias, hongos y levaduras que contenían la matriz sin irradiar.
Crystal Forms of the Antihypertensive Drug Irbesartan: A Crystallographic, Spectroscopic, and Hirshfeld Surface Analysis Investigation
(American Chemical Society (ACS) (Estados Unidos), 2022) Araya Sibaja, Andrea Mariela; Fandaruff, Cinira; Guevara-Camargo, Ana María; Vargas-Huertas, Felipe; Zamora Ramírez, William J.; Jose-Roberto, Vega-Baudrit; Guillen-Girón, Teodolito; Navarro-Hoyos, Mirtha; Paoli, Paola; Rossi, Patrizia; Jones, William
Abstract. 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 singlecrystal 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.
Membranas de Quitosano obtenidas a partir de Biomasa: Efecto contra Fusarium Verticillioides
(Universidad del País Vasco (España), 2021) Lluberas, Gabriela; Herrera, Jimena M.; Montes de Oca-Vásquez, Gabriela; Batista Menezes, Diego; Raimonda, Pablo; Jose-Roberto, Vega-Baudrit; Zygadlo, Julio A.; Lopretti, Mary
Resumen. La industrialización de la biomasa de granos y cereales ha demostrado ser valiosa para los residuos industriales que no se utilizan en todo su potencial. En este trabajo se utilizó aceite de soja como emulsionante y quitosano como biopolímero para formar membranas con actividad antifúngica. Las membranas de quitosano se fabricaron por emulsificación (w/o). En las membranas, incorporamos biopesticidas como fenoles funcionalizados (FF) y 1–octen–3–ol por adsorción e inclusión. Así, se evaluaron las propiedades ópticas, mecánicas, térmicas, químicas y biológicas. Se evaluó la actividad antifúngica de las membranas que contenían FF frente a Fusarium verticillioides. Las micrografías electrónicas de barrido determinaron membranas con diferentes morfologías según el método de incorporación, inclusión y adsorción. El ensayo de tracción de las membranas de control y de las membranas con FF mostró un porcentaje de elongación del 5%, y la ruptura de la probeta a 1,95 kg·cm-2. Las membranas desarrolladas fueron eficaces en el control de la plaga de los granos almacenados, mostrando un 80% de inhibición del crecimiento de Fusarium verticillioides.
Design of Hybrid Polymeric-Lipid Nanoparticles Using Curcumin as a Model: Preparation, Characterization, and In Vitro Evaluation of Demethoxycurcumin and Bisdemethoxycurcumin-Loaded Nanoparticles
(Multidisciplinary Digital Publishing Institute (MDPI) (Suiza), 2021) Wilhelm, Krissia; Quiros, Maria Isabel; Vargas-Huertas, Felipe; Jose-Roberto, Vega-Baudrit; Navarro-Hoyos, Mirtha; Araya Sibaja, Andrea Mariela
Abstract. Polymeric lipid hybrid nanoparticles (PLHNs) are the new generation of drug delivery systems that has emerged as a combination of a polymeric core and lipid shell. We designed and optimized a simple method for the preparation of Pluronic F-127-based PLHNs able to load separately demethoxycurcumin (DMC) and bisdemethoycurcumin (BDM). CUR was used as a model compound due to its greater availability from turmeric and its structure similarity with DMC and BDM. The developed method produced DMC and BDM-loaded PLHNs with a size average of 75.55 ± 0.51 and 15.13 ± 0.014 nm for DMC and BDM, respectively. An FT-IR analysis confirmed the encapsulation and TEM images showed their spherical shape. Both formulations achieved an encapsulation efficiency ≥ 92% and an exhibited significantly increased release from the PLHN compared with free compounds in water. The antioxidant activity was enhanced as well, in agreement with the improvement in water dissolution; obtaining IC50 values of 12.74 ± 0.09 and 16.03 ± 0.55 for DMC and BDM-loaded PLHNs, respectively, while free curcuminoids exhibited considerably lower antioxidant values in an aqueous solution. Hence, the optimized PHLN synthesis method using CUR as a model and then successfully applied to obtain DMC and BDM-loaded PLHNs can be extended to curcuminoids and molecules with a similar backbone structure to improve their bioactivities.
Persea Americana Agro-Industrial Waste Biorefinery for Sustainable High-Value-Added Products
(Multidisciplinary Digital Publishing Institute (MDPI) (Suiza), 2021) Mora-Sandí, Anthony; Ramírez-González, Abigail; Castillo-Henríquez, Luis; Lopretti-Correa, Mary; Jose-Roberto, Vega-Baudrit
Abstract. Significant problems have arisen in recent years, such as global warming and hunger. These complications are related to the depletion and exploitation of natural resources, as well as environmental pollution. In this context, bioprocesses and biorefinery can be used to manage agro-industrial wastes for obtaining high-value-added products. A large number of by-products are composed of lignin and cellulose, having the potential to be exploited sustainably for chemical and biological conversion. The biorefinery of agro-industrial wastes has applications in many fields, such as pharmaceuticals, medicine, material engineering, and environmental remediation. A comprehensive approach has been developed toward the agro-industrial management of avocado (Persea americana) biomass waste, which can be transformed into high-value-added products to mitigate global warming, save non-renewable energy, and contribute to health and science. Therefore, this work presents a comprehensive review on avocado fruit waste biorefinery and its possible applications as biofuel, as drugs, as bioplastics, in the environmental field, and in emerging nanotechnological opportunities for economic and scientific growth.
Cardanol: Una Alternativa Ecológica para Potenciales Aplicaciones en la Industria de los Polímeros
(Universidad del País Vasco (España), 2019) Herrera Báez, Randall; Vargas Jiménez, Christian; Herrera Ubau, Mario; Jose-Roberto, Vega-Baudrit
Resumen. Teniendo en cuenta la forma en que se llevan a cabo los procesos dentro del sector industrial desde hace varios años, es claro destacar el consumo excesivo de recursos naturales no renovables y el uso de materias primas tóxicas para la elaboración de productos. Debido a esto, ha surgido una tendencia en la cual se fomenta el uso inteligente de los recursos, y además, la sustitución de materiales contaminantes y dañinos para la salud humana por otros que presentan características más apropiadas. El cardanol aparece como una alternativa valiosa que resuelve los problemas descritos anteriormente. Este se obtiene a partir del líquido de la cáscara de anacardo (CNSL), el cual es un subproducto del procesamiento de las semillas de la fruta, que generalmente se desecha. Este compuesto, debido a su estructura fenólica con un sustituto meta sustituido de cadena alifática, resulta ser una materia prima muy versátil que puede sufrir una gran variedad de reacciones químicas para formar intermediarios importantes en los procesos de síntesis de resinas, medicamentos, surfactantes, entre otros. La presente revisión bibliográfica, tiene como objetivo, analizar desde un punto de vista de la aplicación, el potencial del cardanol como materia prima sostenible y no tóxica, en la elaboración de diferentes productos industriales.
Bio Refinery of Oily Wastes
(Juniper Publishers (Estados Unidos), 2018) Rojas Alfaro, Juan José; Fernández Araya, Luis Marcial; Redondo, Carlos; Jose-Roberto, Vega-Baudrit
Abstract. Many attempts have been made in order to establish a concept for biorefinery. The simplest way to do so is in an analogous way to the current oil refinery, where multiple fuels and products are manufactured from fossil source, but in the biorefinery scenario, biomass is converted into a range of biochemicals, materials and energy products in an industrial process.

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