Browsing by Author "Cussa, Jorgelina"

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Controlled drug release system: MCF-Chlorambucil mesoporous foam
(2022) Juárez, Juliana M.; Cussa, Jorgelina; Anunziata, Oscar Alfredo; Goméz Costa, Marcos Bruno
Mesostructured cellular foam (MCF) is a promising material for drug delivery systems due to its high biocompatibi0lity, biodegradability, and low toxicity. Its properties include a large surface area, uniform large pore. In this work, the MCF mesoporous foam was successfully synthesized for its application in drug nanocarriers, specifically Chlorambucil, obtaining the MCF-CLB composite. The synthesis of the mesoporous material and the process of incorporation of Chlorambucil in the pores of the MCF were successful as shown in the XRD, UV Vis Ref. Difusa, TEM analysis and analysis of textural properties. The release of the drug was conducted by simulating the physiological conditions to reproduce the conditions of the organism. The mechanism of drug release from the MCF-CLB host was evaluated. Different mathematical models were used to adjust the experimental data, the best model describing the phenomenon under study over the entire period is the Weibull model. The auspicious results we attained for the release of the drug using the new material, the main advantage of this release is that the rate of release is fast at the beginning and then gradually decreases until 24 h practically all the drug contained in the carrier is released (>95%).
Drug delivery system: large pore SBA-15 as host for ketorolac tromethamine
(2022) Juárez, Juliana María; Cussa, Jorgelina; Anunziata, Oscar Alfredo; Gómez Costa, Marcos Bruno
Drug-controlled release systems can keep the level of drugs in precise doses in the body above the optimal level and with low toxicity. We propose the LP-SBA-15 nanomaterial as a promising new host for drug delivery systems because of its high biocompatibility, in vivo biodegradability, and low toxicity. Ketorolac-LP-SBA-15 was prepared and characterized by XRD, FTIR, UV-Vis DRS, TEM, and texture analysis, determining the adsorption capacity and its release, achieving the required therapeutic efficacy. The host shows ordered mesoporous nanochannels with a diameter of 11-12 nm, maintaining the structure with the incorporation of Keto. The mechanism of drug release the LP-SBA-15 host was evaluated. Different mathematical models were used to adjust the experimental data, being the Ritger-Peppas model followed by the Weibull model the best ones. In this work, we show a promising drug storage material for effective encapsulation and controlled release of KETO, achieving the required therapeutic efficacy. Studies indicate that KETO was adsorbed on the channel surface of LP-SBA-15 without affecting the structure or chemical composition of KETO. Controlled drug delivery systems can achieve precise delivery at the time and place of destination, keeping the concentration of the drug at points in the body within the optimal range and below the toxicity threshold. The study also demonstrates the storage capacity and release properties of LPSBA-15 containing KETO. The release of KETO contained in LP-SBA-15 can offer a significant improvement in the controlled release of the drug and the analgesic and anti-inflammatory effects, positively influenced, by the links formed between the host and drug molecules and by diffusion through the host porosity. The promising results we obtained for the release of the drug thoroughly using the new material, reaching a rapid initial release rate, and maintaining a constant rate afterward, allow us to maintain the concentration of the drug in the therapeutic efficacy range, applying it largely to the treatment of diseases that require a rapid response.
Efficient retention of fluorides using SBA-3mesoporous Material.
(Univesidsad Tecnológica Nacional, 2022) Cussa, Jorgelina; López , Claudia; Anunziata, Oscar Alfredo; Anunziata, Oscar Alfredo
Highly ordered pore mesoporous silica composites, like SBA-3 and hydroxyapatite (HaP) nanocrystals, characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and textural properties, were successfully applied to remove fluoride from contaminated water. The proposed procedure to prepare HaP/SBA-3 was successful, which acts as supports to anchor the HaP crystals, in nanometer-scale (<2 nm), with higher fluoride retention from contaminated water. The free OH- groups of HaP nanocrystals, within the host, facilitated the high-performance fluoride trapping. The fluoride retention activity was much higher than that of pure HaP and the composites HaP/SBA-15 and HaP/MCM-41.
EXperimental design optimization of the ODS of DBT using vanadium oXide supported on mesoporous Ga-SBA-15
(2020) Rivoira, Lorena Paola; Cussa, Jorgelina; Martínez, María Laura; Beltramone, Andrea Raquel
EXperiment design-response surface methodology is applied in this work to model and optimize the o Xidation of dibenzothiophene (DBT) using VOX-Ga-SBA-15 catalyst. The analyzed variables are the influence of the nature of the catalyst (V and Ga loading), the s ubstrate/catalyst mass ratio (g DBT/g of catalyst) and the o Xidant/substrate molar ratio (H2O2/DBT). The response analyzed is conversion of DBT at 15 min of reaction time. A set of re- sponse surfaces were obtained applying the BoX-Behnken Design. Based on statistical methodology it was pos- sible to find the best arrangement between the amounts of the gallium heteroatom and the vanadium active species. The higher levels of the objective function were obtained employing the catalyst with 4 wt.% of gallium and 6 wt.% of vanadium; the optimal ratio between g DBT/g of catalyst was 4 and the molar ratio between H2O2/DBT was 5. Gallium incorporation as heteroatom in tetrahedral position allowed the better anchorage ofthe active species of vanadium, generating a very well dispersed catalyst. The optimized catalyst minimized the mass transfer limitation and moreover, was active after several recycles. The best catalyst was likewise very active for the oXidation of the most refractory sulfur compounds as benzothiophene and 4,6-dimetyldi- benzothiopene.
HaP / LP-SBA-15 Nanocomposite for efficient removal of fluoride from contaminated wáter
(2020) López, Claudia G.; Anunziata, Oscar A.; Cussa, Jorgelina
Hydroxyapatite (HaP) composites and highly ordered large pore mesoporous silica, such as LP-SBA-15 (Large Pore-SBA-15), were developed, characterized by XRD, BET, FTIR and HRTEM, and applied properly to fluoride removal from contaminated water. The proposed procedure to prepare HaP/LP-SBA-15 was successful, which acts as supports to anchor the HaP crystals, in nanometer-scale (<12 nm), with higher fluoride retention from contaminated water. The free OH- groups of HaP nanocrystals, inside the host, permitted fluoride retention with high capacity. The fluoride holding activity was over 3 orders of magnitude higher than pure HaP.
HaP/SBA-3 Nanostructured Composite to Remove Fluoride Effectively from Contaminated Water.
(Univesidsad Tecnológica Nacional, 2021) Cussa, Jorgelina; López , Claudia; Anunziata, Oscar Alfredo; Anunziata, Oscar Alfredo
Highly ordered pore mesoporous silica composites, like SBA-3 and hydroxyapatite (HaP) nanocrystals, characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and textural properties, were successfully applied to remove fluoride from contaminated water. The proposed procedure to prepare HaP/SBA-3 wassuccessful, which acts as supports to anchor the HaP crystals, in nanometer-scale (<2nm), with higher fluoride retention from contaminated water. The free OH- groups of HaP nanocrystals, within the host, facilitated the high-performance fluoride trapping. The fluoride retention activity was much higher than that of pure HaP and the composites HaP/SBA-15 and HaP/MCM-41.
Hidrogenación de tetralin utilizando un catalizador bifuncional de iridio/platino-SBA-15
(2014) Vallés, Verónica; Ledesma, Brenda; Rivoira, Lorena Paola; Cussa, Jorgelina; Martínez, María Laura; Anunziata, Oscar Alfredo; Beltramone, Andrea Raquel
Los catalizadores bimetálicos de Pt–Pd han recibido considerable atención debido a que demuestran tener una alta actividad en una amplia variedad de aplicaciones catalíticas (1). Con alta actividad, selectividad y estabilidad, comparada con catalizadores monometálicos de Pt y Pd. Por ejemplo, catalizadores bimetálicos Pt-Pd muestran tener mayor resistencia frente a envenenamientos en comparación con catalizadores de Pt (2-4). Las características estudiadas del catalizador serán correlacionadas con su performance catalítica en la hidrogenación del tetralin. El objetivo final es encontrar la proporción óptima de cada uno de los metales de forma de lograr la mayor actividad en dicho proceso.
Large pore SBA-15 functionalized as drug carrier of Cyclophosphamide.
(Univesidsad Tecnológica Nacional, 2023) Juárez , Juliana María; Cussa, Jorgelina; Anunziata, Oscar Alfredo; Gómez Costa, Marcos Bruno
Controlled drug administration systems can keep the level of drugs in specific locations in the organism with low toxicity and above the optimal level. We suggest the LP-SBA-15 material as an auspicious new host for drug delivery systems because of its low toxicity high biocompatibility and in vivo biodegradability. LP-SBA-15 materials were synthesized and functionalized using 0-15-30% of tert-butylamine (TBA) and used as effective drug delivery systems. The anticancer drug Cyclophosphamide (CP) is an alkylating compound which is a phosphoramide derivative and is habitually used in autoimmune diseases. Reactive oxygen species production has been related to the mechanism of CP-induced cell death or tumor cell killing. The activated metabolites of CP are released in both healthy and tumor tissues and destroy the cellular DNA and proteins as well as mitochondrial and lysosomal membranes. CP was loaded into the nanomaterial of the transporters and characterized by N2 adsorption-desorption, Ultraviolet-visible diffusereflectance spectroscopy (UV-Vis DRS), FTIR, determining the adsorption capacity and its release. The release of the drug was studied for each material by simulating the physiological conditions and submerging the composite, at 37 °C with constant stirring, in a HCl solution (0.1 M) for the first two hours and in Buffer solution pH = 7 the following hours to simulate the conditions of the organism. Release experiments were conducted to determine the requisite efficacy of treatment. The study was performed by UV-Vis spectrophotometry to evaluate the amount of CP released. The mechanism of drug release from the LP-SBA-15 functionalized matrix was evaluated by adjusting the experimental data, being the Ritger-Peppas model, Weibull model and First-Order model, the best models to adjust the experimental data is the, which is confirmed by the R2 coefficient of determination. The promising results we obtained for the controlled release of the drug in a controlled manner using the new material, reaching a quick initial release rate and maintaining a constant rate at high moments, allow us to keep the concentration of the drug in the therapeutic efficacy range, applying itto a great extent to the treatment of diseases that require a rapid response. Lastly, it was suggested thatthe LP SBA-15 nanomaterial functionalized with 15% TBA was the most desirable system due to they had adequate amounts of both drug loading and release
LP-SBA-15, functionalized with tert-butylamine a novel controlled release system for cyclophosphamide.
(Univesidsad Tecnológica Nacional, 2013) Juárez , Juliana María; Cussa, Jorgelina; Gómez costa , Marcos Bruno; Anunziata, Oscar Alfredo; Anunziata, Oscar Alfredo
Controlled drug administration systems can keep the level of drugs in specific locations in the organism with low toxicity and above the optimal level. We suggest the LP-SBA-15 material as an auspicious new host for drug delivery systems because of its low toxicity high biocompatibility and in vivo biodegradability. LP SBA-15 materials were synthesized and functionalized using 0-15-30% of tert butylamine (TBA) and used as effective drug delivery systems. The anticancer drug Cyclophosphamide (CP) is an alkylating compound which is a phosphoramide derivative and is habitually used in autoimmune diseases. Reactive oxygen species production has been related to the mechanism of CP-induced cell death or tumor cell killing. The activated metabolites of CP are released in both healthy and tumor tissues and destroy the cellular DNA and proteins as well as mitochondrial and lysosomal membranes. CP was loaded into the nanomaterial of the transporters and characterized by XRD, FTIR, TGA, TEM and texture, determining the adsorption capacity and its release. The release of the drug was studied for each material by simulating the physiological conditions and submerging the composite, at 37 °C with constant stirring, in a HCl solution (0.1 M) for the first two hours and in Buffer solution pH = 7 the following hours to simulate the conditions of the organism. Release experiment were conducted to determine the requisite efficacy of treatment. The study was performed by UV-Vis spectrophotometry to evaluate the amount of CP released. The mechanism of drug release from the LP-SBA-15 matrix was evaluated by adjusting the experimental data, being the Ritger-Peppas (figure 1) The promising results we obtained for the controlled release of the drug in a controlled manner using the new material, reaching a quick initial release rate and maintaining a constant rate at high moments, allow us to keep the concentration of the drug in the therapeutic efficacy range, applying it to a great extent to the treatment of diseases that require a rapid response. Lastly, it was suggested that the LP-SBA-15 nanomaterial functionalized with 15% TBA was the most desirable system due to they had adequate amounts of both drug loading and release
LP-SBA-15-TBA-CP: Tert-Butylamine and Cyclophosphamide detailed study by FTIR and 3D structure.
(Univesidsad Tecnológica Nacional, 2023) Anunziata , Oscar Alfredo; Cussa, Jorgelina
A careful study of the vibrational spectra of the host (LP-SBA-15), functionalizing agent, tert-Butylamine (TBA), and N, N-bis(2-chloroethyl)tetrahydro-2H-1,3,2- oxazaphosphorin-2-amine 2-oxide, cyclophosphamide (CP) was performed, as there is a diversity of assignments published by different authors [1-5]. Our preliminary OM studies (AM1, PM3, Density Functional Theory, application of the Fukui function), and extensive FTIR studies, we estimated the binding energies, bond lengths and bond angles of CP as well as for TBA-CP, leading us to suggest that CP is embedded in an ellipsoid.
LP-SBA-15/ketorolac nanocomposite: development, characterization, and mathematical modeling of controlled keto release
(2022) Cussa, Jorgelina; Juárez, Juliana María; Gómez Costa, Marcos Bruno; Anunziata, Oscar Alfredo
Drug-controlled release systems can keep the level of drugs in precise doses in the body above the optimal level and with low toxicity. We propose the nanomaterial LP-SBA-15 as an attractive new host for drug delivery systems due to its high biocompatibility, in vivo biodegradability, and low toxicity. LP-SBA-15/Ketorolac was prepared and characterized by XRD, FTIR, UV-Vis DRS, TEM, and texture analysis, determining the adsorption capacity and its release and achieving the required therapeutic efficacy. The host shows the ordered mesoporous nanochannels with a diameter of 11-12 nm, maintaining the structure with the incorporation of Keto. The mechanism of drug release from the LP-SBA-15 host was evaluated. Different mathematical models were used to adjust the experimental data, the Ritger-Peppas model followed by the Weibull model the best ones. The promising results we obtained for the release of the drug thoroughly using the new material, reaching a rapid initial release rate, and maintaining a constant rate afterward, allow us to maintain the concentration of the drug in the therapeutic efficacy range, applying it largely to the treatment of diseases that require a rapid response.
Mesoporous cellular foam (MCF): an efficient and biocompatible nanomaterial for the controlled release of chlorambucil
(2022) Juárez, Juliana María; Cussa, Jorgelina; Anunziata, Oscar Alfredo; Gómez Costa, Marcos Bruno
Nanotransporters have entered a great deal of exploration attention because of their promising openings in medicine delivery. We propose in this work, the Mesostructured siliceous cellular (MCFs) nanomaterial as a promising new host for drug delivery systems because both their specific physicochemical properties, in addition to the high biocompatibility, biodegradability, and low toxicity, make them seductive for controlled medicine release operations. Chlorambucil, is used as a chemotherapy drug administered for treating some types of cancer, chronic lymphocytic leukemia, low-grade non- Hodgkin’s lymphoma, Hodgkin’s lymphoma and ovarian cancer. Chlorambucil-loaded Mesostructured cellular foam (MCF-CLB) was prepared and characterized by XRD, TEM, UV- Vis DRS, FTIR, and texture analysis determining the adsorption capacity and its release, achieving the required therapeutic efficacy. The release of the drug was conducted by simulating the physiological conditions to reproduce the conditions of the organism. The mechanism of drug release from the MCF-CLB host was evaluated. Different mathematical models were used to adjust the experimental data, the best model describing the phenomenon under study over the entire period is the Weibull model. The auspicious results we attained for the release of the drug using the new material. The main advantage of this release is that the rate of release is fast at the beginning and then gradually decreases until 24 h practically all the drug contained in the carrier is released (> 95%).
Nanostructured SBA-15 host applied in ketorolac tromethamine release system
(Springer Science+Business Media, 2017) Cussa, Jorgelina; Juárez, Juliana María; Gómez Costa, Marcos Bruno; Anunziata, Oscar Alfreco
The ordered mesoporous silica SBA-15 has been applied in studies of ketorolac tromethamine adsorption andrelease. The SBA 15 materials with hexagonal and regular structure were obtained using a triblock copolymer Pluronic P123 as a template and TEOS as a silica source. Ketorolac tromethamine was adsorbed into SBA 15 silica nanochan- nels using ethanol as solvent. The physicochemical and textural properties of SBA-15 and ketorolac tromethamine/ SBA-15 were characterized by X-ray diffraction, thermo gravimetric analysis, transmission electron microscopy, fourier transform infrared spectroscopy and BET surface studies. Drug release was evaluated by soaking the loaded silica mesoporous material into a solution of HCl (0.1 N) at initial time (0–2 h) and buffer pH 7 at high times at 37 °C under continuous stirring. Oral commercial Keto tablets (Dolten® ) and Keto solution (Keto power) were study for the contrast. Release studies were performed in order to evaluate the required therapeutic efficacy. SBA 15 provides significant improvement in the controlled release of ketor- olac tromethamine.
Optimization of NOx selective catalytic reduction in presence of iso-butane and 02 using Fecontaining ZSM-11 zeolites by multivariate analysis.
(Univesidsad Tecnológica Nacional, 2012) Cussa, Jorgelina; Beltramone, Andrea; Anunziata, Oscar
The nitrogen oxides reduction is a problem that the environmental catalysis still tries to solve. Thus, for this problematic, the processes can be grouped in three general lines of work: minimization of the production of NOx; direct decomposition of NO to N2 + O2, and selective catalytic reduction (SCR). Fe-ZSM-5 has in recent times received much attention in catalysis research because of its promising activity in the decomposition or selective reduction of nitrous oxide. Fe-ZSM-11 zeolites, prepared by novel sol-gel process with Fe2+ and/or Fe3+ as active sites incorporated by reproducible post-synthesis methods were obtained. We reported the relationship between the catalytic activity and the nature of the active sites [1]. The experiment design - response surface methodology is used in this work to optimize the NOx selective catalytic reduction to N2 using the above cited catalyst. The main objective is to define the response surfaces, finding the best combination of different parameters in order to optimize the process, for this reason, the experiments design methodology was applied reducing the operation costs, achieving efficiency and effectiveness in the process. The application of this methodology leads us to a better understanding of the influence of the different factors such as: number and strength of the acid sites, Fe2+/Fe3+ relation, [NO3*] and [NO2*] adsorbed intermediates, the concerted reaction mechanism proposed in the previous work, and the effect of the reaction temperature and their interactions. The statistic model applied in this work is a powerful tool to interpret the overall process from the multivariate parameters. The goal of the present work would be to identify the key-factors to optimizing the best operation conditions and catalysts characteristics, which are responsible for the enhanced performance of Fe-zeolites and thereby to corroborate with even better catalyst formulations. According to the statistic methodology applied, the best operation conditions and catalysts characteristics can be identified, allowing us to re-design the catalyst to enhance the NOx conversion and N2 and CO2 selectivity at optimum reaction temperature.
Optimization of the synthesis of SBA-3 mesoporous materials by experimental design
(Elsevier Inc., 2016-02-18) Ponte, María Virignia; Rivoira, Lorena Paola; Cussa, Jorgelina; Martínez, Maria Laura; Beltramone, Andrea Raquel; Anunziata, Oscar Alfredo
SBA-3 mesoporous materials are characterized by hexagonal regular arrangements of channels with diameters >2 nm, high specific surface areas and high specific pore volumes. In the work reported herein, experimental design-response surface methodology (RSM) is used to model and optimize the synthesis conditions for SBA-3 mesoporous materials. In this study, we evaluate the influences of surfactant/silica source molar ratios, aging times, temperature and pH on the synthesis of SBA-3 mesoporous materials by analyzing the XRD intensities pertaining to the [100] signal. Response surfaces were obtained using the BoxeBehnken design, and the combination of reaction parameters was optimized. By applying statistical methodology, higher levels of the objective function (XRD intensities pertaining to the [100] signal) were obtained using cetyltrimethylammonium bromide (CTAB)/tetraethyl orthosilicate (TEOS) molar ratios of 0.07 and 0.16, HCl/TEOS molar ratios of 8 and 11, reaction temperatures of 35 and 45 ◦C and aging times of 12e24 h. The mesoporous SBA-3 samples obtained were characterized using small-angle X-ray powder diffraction (XRD), BET, FTIR and 29Si NMR-MAS, scanning electron microscopy (SEM) and transmission electron microscopy (TEM).
Preparation, characterization and mathematical modeling of keterolac release conteined in lpsba-15 host
(2021) Cussa, Jorgelina; Juárez, Juliana M.; Gómez Costa, Marcos B.; Anunziata, Oscar A.
Drug-controlled release systems can keep the level of drugs in precise doses in the body above the optimal level and with low toxicity. We propose the LP-SBA-15 nanomaterial as a promising new host for drug delivery systems because of its high biocompatibility, in vivo biodegradability, and low toxicity. Ketorolac-LP-SBA-15 was prepared and characterized by XRD, FTIR, UV-Vis DRS, TEM, and texture analysis, determining the adsorption capacity and its release, achieving the required therapeutic efficacy. The host shows ordered mesoporous nanochannels with a diameter of 11-12 nm, maintaining the structure with the incorporation of Keto. The mechanism of drug release the LP-SBA-15 host was evaluated. Different mathematical models were used to adjust the experimental data, being the Ritger-Peppas model followed by the Weibull model the best ones. In this work, we show a promising drug storage material for effective encapsulation and controlled release of KETO, achieving the required therapeutic efficacy. Studies indicate that KETO was adsorbed on the channel surface of LP-SBA-15 without affecting the structure or chemical composition of KETO. Controlled drug delivery systems can achieve precise delivery at the time and place of destination, keeping the concentration of the drug at points in the body within the optimal range and below the toxicity threshold. The study also demonstrates the storage capacity and release properties of LPSBA- 15 containing KETO. The release of KETO contained in LP-SBA-15 can offer a significant improvement in the controlled release of the drug and the analgesic and anti-inflammatory effects, positively influenced, by the links formed between the host and drug molecules and by diffusion through the host porosity. The promising results we obtained for the release of the drug thoroughly using the new material, reaching a rapid initial release rate, and maintaining a constant rate afterward, allow us to maintain the concentration of the drug in the therapeutic efficacy range, applying it largely to the treatment of diseases that require a rapid response.
Simultaneous optimization of methane conversion and aromatic yields by catalytic activation with ethane over Zn-ZSM-11 zeolite: the influence of the Zn-loading factor
(2011) Anunziata, Oscar Alfredo; Cussa, Jorgelina; Beltramone, Andrea Raquel
Experiment design-response surface methodology (RSM) is used in this work to model and optimize two responses in the process of activation of methane (C1) using ethane (C2) as co-reactant into higher hydro- carbons, over Zn-containing zeolite catalysts. The application of this methodology provides insights into a more comprehensive understanding of the influence attributed to from the different factors. In this study we analyze the influence of the C1 molar fraction (C1/C1 + C2), the reaction temperature and the Zn-loading factors. The responses analyzed were as follows: Y1: C1 conversion (mol% C) and Y2: aromatic hydrocarbon yields (mol% C). The response surfaces were obtained with the Box–Behnken Design, finding the best combination between the reaction parameters that allowed optimizing the process. By applying the statistic methodology, the higher levels of the two objective functions, C1 conversion of 48.6 mol% C and aromatic yields of 47.2 mol% C, were obtained employing, a higher temperature, 0.2–0.4 molar frac- tion of C1 and the catalysts with a higher Zn2+ content.
Síntesis y caracterización de SBA-3: a partir de una sal metalica
(2014) Ponte, María Virginia; Martínez, María Laura; Cussa, Jorgelina; Anunziata, Oscar Alfredo; Beltramone, Andrea Raquel
Materiales porosos bimodales son materiales que poseen poros de dos tamaños diferentes. En estos materiales, las superficies de los pequeños poros pueden interactuar con moléculas, mientras que grandes poros proporcionan rutas de alta velocidad para el transporte de moléculas de gas y líquidos. Estos materiales poseen numerosas aplicaciones potenciales como adsorbentes, tamices moleculares y soportes de catalíticos. En todos los casos, el área superficial y tamaño de poro de estos materiales son de fundamental importancia debido al hecho de que pequeños poros puede promover una interacción entre los materiales porosos y las moléculas huéspedes. En este trabajo, se sintetizan por primera vez materiales mesoporosos del tipo SBA-3 utilizando como fuente de silicio, una diferente al Tetaetilortosilicato (TEOS), una sal metálica como lo es el silicato de sodio. Los materiales sintetizados son caracterizados en primera instancia mediante XRD. El procedimiento empleado para la síntesis de los materiales mesoporosos del tipo SBA-3 es el que se detalla a continuación. Se preparan dos soluciones: Solución A) solución de silicato de sodio: se parte de sílica gel, el cual es disuelto en una solución de NaOH y solución B) Se disuelve el agente direccionante de estructura (Bromuro de cetiltrimetil amonio (CTAB)) en agua destilada acidificada con HCl. Una vez obtenidas las dos soluciones, la solución A es agregada a la solución B por medio de goteo bajo condiciones de agitación (400 rpm) y temperatura ambiente. Pasada una hora, el precipitado es filtrado, lavado con agua destilada y secado a 50ºC toda la noche. Posteriormente, el surfactante es eliminado por medio de calcinación no oxidativa con flujo de N2 con un caudal de 20 ml/min a 500ºC durante un periodo de 5 horas, seguido de calcinación oxidativa en mufla a 550 ºC en aire por 5 h, aumentando la temperatura con una rampa de 5ºC/min. La composición final de la síntesis original fue de SiO2:NaO:CTAB:HCl:H2O=1:1,2:0,13:32:86, y el material obtenido se denominó SBA-3(SG). El material obtenido fue caracterizado por la técnica de XRD. Los picos característicos correspondientes a los planos de difracción (1 0 0), (1 1 0) y (2 0 0) fueron observados. Espectroscopia FT-IR se utilizó para investigar la vibración de estiramiento T–O–T (T representa Si). Las bandas características de Si tetraédrico se encontraron a 1080 y 800 cm-1 las cuales son generalmente insensibles a la estructura.
Síntesis y caracterización de un catalizador soportado iridio/platino-SBA-15 para su aplicación
(2014) Vallés, Verónica; Ledesma, Brenda; Rivoira, Lorena Paola; Cussa, Jorgelina; Martínez, María Laura; Anunziata, Oscar Alfredo; Beltramone, Andrea Raquel
En el presente trabajo se estudió el efecto de la dispersión de metales nobles Ir y Pt y la interacción con el soporte SBA-15, relacionándolos con la actividad catalítica del catalizador en la reacción de hidrogenación del Tetralin utilizando un reactor Parr a 250°C y 15 atm. Con este objetivo se sintetizaron catalizadores Ir/Pt-SBA-15 modificados con distintos % de Ir y Pt. La mesoestructura del soporte SBA-15 le confiere una estabilidad térmica relativamente alta y el diámetro apropiado de poro permite convertir moléculas voluminosas como las presentes en los cortes de combustibles líquidos. El soporte fue preparado por el método de sol-gel. Para la obtencion del sitio catalitico se utilizó l método de impregnación incipiente. Se disuelven el Acetil acetonato de Iridio (IrAcAc) y el Acido cloroplatinico hidratado (H2PtCl6.H2O) en 50 ml de etanol a 50ºC con reflujo. Luego se agrega a la SBA-15 previamente pesada la solución y se lo lleva a un evaporador rotatorio a 60 ºC y 70 rpm hasta lograr evaporar todo el solvente. Luego se deja secando en estufa a 110 ºC por 24 h. Posteriormente es calcinado en mufla a 500 ºC por 5 horas, seguido de reducción con hidrógeno. El material fue caracterizado mediante difracción de rayos X (XRD), se puede observar que conserva la estructura mesoporosa a bajo ángulo, mientras que a alto ángulo se observan los índices de refracción característicos de Ir y Pt metálicos. También fueron caracterizados por XPS y TEM. La dispersión del Me fue calculada mediante quimisorción de H2 se obtuvieron partículas de iridio/Platino (d= 4,0-2.0 nm) homogéneamente disperso, con una dispersión de más del 60%. Se obtuvo una
Síntesis, caracterización y aplicación del nanomaterial lp-sba-15 en la liberación controlada de ketorolac trometamina
(2020) Juárez, Juliana M.; Gómez Costa, Marcos B.; Cussa, Jorgelina
Los sistemas controlados de administración de fármacos pueden mantener la concentración de medicamentos en los sitios exactos del cuerpo dentro del rango óptimo y por debajo del umbral de toxicidad, mejorando la eficacia terapéutica y reduciendo la toxicidad. El material LP-SBA-15 es un nuevo huésped prometedor para los sistemas de administración de fármacos debido a su alta biocompatibilidad, biodegradabilidad in vivo y baja toxicidad. Se sintetizó el composite ketorolac-trometamina/LP-SBA-15. La síntesis del material y la carga de ketorolac-trometamina en los poros LP-SBA-15 fue exitosa, como lo demuestran los análisis XRD, FTIR, TGA, TEM y análisis morfologicos. Obtuvimos resultados prometedores para la liberación controlada de fármacos utilizando el nuevo material. La aplicación de estos materiales en la liberación de KETO es innovadora, logrando una alta tasa de liberación inicial y luego manteniendo una liberación más lenta. Esto permite mantener la concentración del fármaco dentro del rango de eficacia terapéutica, siendo altamente aplicable para el tratamiento de enfermedades que necesitan una respuesta rápida.

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