Browsing by Author "Anunziata, Oscar Alfredo"

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    Controlled drug release system: cyclophosphamide delivery contained in LP-SBA-15 functionalized with tertbutylamine.
    (Univesidsad Tecnológica Nacional, 2023) Cussa, Jorgelina; Juárez , Juliana María; Gómez Costa, Marcos Bruno; Anunziata, Oscar Alfredo; Anunziata, Oscar Alfredo; Juárez , Juliana María
    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-SBA15 material as a 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. 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.
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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%).
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    Controlled drug release system: MCF-Chlorambucil mesoporous foam.
    (Univesidsad Tecnológica Nacional, 2022) Júarez , Juliana María; Cussa , Jorgelina; Anunziata, Oscar Alfredo; Gómez Costa, Marcos Bruno; Anunziata, Oscar Alfredo
    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%).
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    Desulfuración oxidativa utilizando material mesoporoso Ti-SBA-16
    (2014) Rivoira, Lorena Paola; Vallés, Verónica; Ledesma, Brenda; Martínez, María Laura; Anunziata, Oscar Alfredo; Beltramone, Andrea Raquel
    La oxidación de compuestos organosulfurados conduce a la formación de los sulfóxidos/sulfonas correspondientes, lo que permite que sean fácilmente removidos mediante extracción en solventes polares o por adsorción. El proceso de ODS es llevado a cabo bajo condiciones muy suaves, comparado con el proceso convencional de HDS. El objetivo del presente trabajo es estudiar el efecto del método de preparación de SBA-16 modificada con titanio en el rendimiento de la ODS del DBT con H2O2 y acetonitrilo como solvente en condiciones suaves de reacción. Se estudiaron dos materiales TiO2-SBA-16 obtenido por impregnación húmeda y Ti-SBA-16 obtenido mediante síntesis directa. con una relación de Si/Ti=20. Para la actividad catalítica se lleva a cabo la reacción de oxidación a 70°C y presión atmosférica se utilizó un reactor batch. Se utilizó H2O2 como agente oxidante y acetonitrilo como solvente.
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    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.
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    Drug release system: Chlorambucil loaded in mesoporous cellular foam (MCF)
    (2022) Juárez, Juliana María; Anunziata, Oscar Alfredo; Gómez Costa, Marcos Bruno
    Nanotransporters have received a great deal of research attention because of their promising opportunities in drug delivery [1-5]. Attempting to minimize the secondary adverse events of anticancer drugs and enhance the therapeutic rate, various nanotransporters have been devised, including dendrimers [6, 7], liposomes [8, 9], inorganic nanoparticles, and polymeric nanoparticles [10-13]. Chlorambucil (CLB), is a substance classified as a human carcinogen [14], it is used as a chemotherapy drug administered for treating some types of cancer. It is mainly used to treat chronic lymphocytic leukemia, low-grade nonHodgkin's lymphoma, Hodgkin's lymphoma and ovarian cancer. Chemically, it is 4-[4-bis(2-chloroethyl) amino phenyl butyric acid. MCFs (mesostructured siliceous cellular foams), that can be derived after the inclusion of a bulking medium in the synthesis procedure of SBA-15 [4], are composed of spherically uniform cells 15-50 nm diameter [15], exhibit high surface areas and porosities, and have adjustable pore size distributions [15, 16]. The open large pore system gives MCF unique advantages as catalyst support and separation media for processes involving large molecules. In addition to their specific physicochemical properties, they possess high biocompatibility and low adverse effects, which with their biodegradability, making them attractive for controlled drug release applications.
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    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.
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    Eliminación de azufre mediante desulfuración oxidativa con SBA-16 modificada con titanio
    (2014) Rivoira, Lorena Paola; Vallés, Verónica; Ledesma, Brenda; Martínez, María Laura; Anunziata, Oscar Alfredo; Beltramone, Andrea Raquel
    La oxidación de compuestos organosulfurados conduce a la formación de los sulfóxidos/sulfonas correspondientes, los cuales son mucho más polares, lo que permite que sean fácilmente removidos mediante extracción en solventes polares o por adsorción. El proceso de ODS es llevado a cabo bajo condiciones muy suaves (presión atmosférica y 60-90ºC), comparado con el proceso convencional de HDS, donde comúnmente son usadas presiones mayores a los 30 bar y temperaturas desde los 300 a los 380ºC. Resultados recientes muestran que tamices moleculares que contienen Ti exhiben buena reactividad catalítica en la oxidación de sulfuro, mercaptano, tiofeno y derivados (1). El objetivo del presente trabajo es estudiar el efecto del método de preparación de SBA-16 modificada con titanio (características de las especies activas de Ti y/o TiO2) en el rendimiento de la ODS del DBT con H2O2 y acetonitrilo como solvente en condiciones suaves de reacción.
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    Estudio de la influencia de la temperatura de síntesis y la concentración de surfactante en la síntesis de SBA-3
    (2014) Ponte, María Virginia; Martínez, María Laura; Gómez Costa, Marcos Bruno; Anunziata, Oscar Alfredo; Beltramone, Andrea Raquel
    En este trabajo se presentan resultados de preparación y caracterización de SBA-3, estudiando la variación de la temperatura de síntesis, así como la de la relación molar CTAB/TEOS. Condiciones de síntesis suaves (303 K) y adecuadas relaciones de surfactante/precursor de silicio conducen a un material mesoporoso con un ordenamiento regular hexagonal, característico de SBA-3 con elevada regularidad estructural.
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    H2 storage using Zr-CMK-3 developed by a new synthesis method
    (2021) Juárez, Juliana María; Venosta, Lisandro F.; Anunziata, Oscar Alfredo; Gómez Costa, Marcos Bruno
    One of the biggest problems in using hydrogen as an alternative fuel is that its storage must be safe and portable. This work addresses a new direct synthesis technique used to obtain a novel mesoporous carbon (CMK-3) modified with zirconium oxide. This novel material shows promise for hydrogen adsorption and storage application for energy harvesting. Zirconium oxide (Zr-CMK-3) material is achieved through successful synthesis and characterized by XRD, SEM, Raman, BET, UV-Vis-DRS, XPS and TEM analyses. Zr-CMK-3 signifi- cantly improved H2 storage performance (reaching at 77 K and 10 bar 4.6 wt%) compared to the pristine CMK-3. The novel material is favorable for H2 uptake by using weak bonding (physisorption). A hydrogen uptake mechanistic approach is proposed and the role of the Zr+4 cation in hydrogen adsorption is discussed.
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    H2 storage using Zr-CMK-3 developed by a new synthesis method.
    (Univesidsad Tecnológica Nacional, 2021) Juárez , Juliana María; Venosta , Lisandro; Anunziata, Oscar Alfredo; Gómez Costa , Marcos Bruno; Anunziata, Oscar Alfredo
    One of the biggest problems in using hydrogen as an alternative fuel is that its storage must be safe and portable. This work addresses a new direct synthesis technique used to obtain a novel mesoporous carbon (CMK-3) modified with zirconium oxide. This novel material shows promise for hydrogen adsorption and storage application for energy harvesting. Zirconium oxide (Zr-CMK-3) material is achieved through successful synthesis and characterized by XRD, SEM,Raman, BET, UV-Vis-DRS, XPS and TEM analyses. Zr-CMK-3 signifi- cantly improved H2 storage performance (reaching at 77 K and 10 bar 4.6 wt%) comparedto the pristine CMK-3. The novel material is favorable for H2 uptake by using weak bonding (physisorption). A hydrogen uptake mechanistic approach is proposed and the role of the Zr+4 cation in hydrogen adsorption is discussed.
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    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.
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    Hidrogenación de tetralin en presencia de quinolina sobre Ir/SBA-16 modificada con titanio
    (2014) Ledesma, Brenda; Vallés, Verónica; Rivoira, Lorena Paola; Anunziata, Oscar Alfredo; Beltramone, Andrea Raquel
    En el presente trabajo informamos resultados de la hidrogenación efectiva de tetralin en presencia de quinolina, en condiciones menos severas que las industriales; para lo cual desarrollamos un nuevo material catalítico mesoporoso Ir/SBA-16 modificado con titanio. La incorporación de Ti facilitó la mayor y mejor homogeneidad en la dispersión de partículas de Ir metálico (Ir0). Para conocer el efecto en la dispersión del metal de transición (1), el Ti fue incorporado vía post síntesis como TiO2 y en red empleando el método sol-gel obteniendo así los catalizadores Ir/TiO2-SBA-16 e Ir/Ti-SBA-16.
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    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.
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    Hydrogenation of tetralin over Ir catalysts supported on titania-modified SBA-16
    (2014) Ledesma, Brenda; Vallés, Verónica; Rivoira, Lorena Paola; Martínez, María Laura; Anunziata, Oscar Alfredo; Beltramone, Andrea Raquel
    Abstract A series of Ti modified SBA-16 supports and their respective Ir-catalysts were prepared and character- ized to study the effect of support preparation method on the dispersion of iridium and on the characteristics of Ir surface species. Two methods of incorporation of titania were tested: the sol–gel method in order to obtain Ti as heteroatom and incipient wetness impregnation to obtain Ti as TiO2 (anatase phase). The results show that supports with different Ti species and dispersion can be obtained. The final catalyst was characterized at different preparation stages by XRD, elemental analysis and BET. The presence of Ti as Ti4? in the nanostructure of SBA and as TiO2 (anatase phase) was analyzed by UV–Vis–DRS and Raman spectroscopy. The iridium oxidation sate upon Ti-con- taining SBA-16 was studied by XPS, EDX, TEM and XRD, arriving at the good proportion of Ir0. H2 chemi- sorption and TEM characterization for Ti-SBA-16 indi- cated that Ir particle size was lower than anatase/SBA-16. The catalyst that we synthesized had good activity mea- sured in tetralin hydrogenation in presence of quinoline at mild conditions. The experimental data were quantitatively represented by a modified Langmuir–Hinshelwood-type rate equation. The preliminary results show these materials as promising catalysts for HDS/HDN reactions.
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    Hydrogenation of tetralin over Ir-containing mesoporous catalysts
    (2012) Vallés, Verónica; Balangero, Gerardo Simón; Martínez, María Laura; Gómez Costa, Marcos Bruno; Anunziata, Oscar Alfredo; Beltramone, Andrea Raquel
    The yield in fluid catalytic cracking (FCC) depends on the extent of aromatic hydrogenation in the gas oil hydrotreater. To optimize the gas oil hydrotreater, it is crucial to understand the aromatic hydrogenation reaction chemistry occurring in the gas oil hydrotreater. Gas oils, which consist of hydrocarbons in the boiling point range of 290−570 °C, contain several aromatic compounds (including three rings, two rings, and one ring). Light cycle oil (LCO), which contains large concentrations of aromatics, has a poor cetane value and, hence, by itself, is a very poor-quality diesel. Because the current regulations [on cetane and polynuclear aromatic (PNA) hydrocarbons] are not stringent, LCO is currently blended with diesel. However, it is anticipated (based on existing regulations in Europe and California) that diesel quality in the near future will be more stringently regulated in terms of cetane and aromatics. To find alternative processes, it is necessary to develop new and more active catalysts to replace the current ones. Optimal design and operation of such hydrogenation processes can be achieved through the use of reliable simulation tools; however, such tools require detailed knowledge of kinetic pathways and rates.1−3 Kinetic experiments on hydrogenation are typically performed in the gas phase under atmospheric pressure on group VIII metal catalysts. Previously, Beltramone et al.4,5 reported a detailed study and a quantitative network analysis of polynuclear aromatics aromatization at industrial conditions, and Korre and Klein6 reported an exhaustive study in a batch reactor at high pressure. Otherwise, the sulfur and nitrogen compounds found in synthetic feedstocks and heavy petroleum fractions can strongly inhibit hydroprocessing reactions through competitive adsorp- tion. The presence of these species even at low concentrations can limit the observed catalytic activity and necessitate the use Article Current processes for dearomatization use catalysts combin- ing the acidity of a support and the hydrogenation and hydrogenolysis/ring-opening activity of an incorporated metal. Hydrogenation/hydrocracking is most often practiced on cyclic molecules over primarily acidic zeolite, alumina, or silica- alumina-supported noble and other group VIII metal catalysts. Different processes have used catalysts such as NiMo, CoMo, NiW, Pt, and Pd on various supports.7−17 The dominance of the acid function can lead to cracking, and thus, a primary focus is the optimization of the acid function. In fact, it was shown recently that significant enhancements in hydrogenation can be made by focusing on the metal function. The metal function is usually provided by Pt and/or Pd, but it has been shown that Ir, Ru, and Rh also have exceptional activities and selectivities for the target reaction of hydrogenation and, depending on the reaction conditions, selective ring-opening.18−20 Some alumina- supported transition-metal catalysts have much higher hydro- denitrogenation (HDN) and hydrodesulfurization (HDS) activities than the conventional NiMo system.21−25 For example, Rh, Ir, Ru, and Pt supported on silica or alumina are known to effectively catalyze nitrogen removal from methylamine, quinoline, or pyridine also in the reduced state.26 Noble-metal sulfides, either unsupported as bulk compounds27 or supported on active carbon,28 have been studied extensively in hydrorefining. It has been shown that transition-metal sulfides of the second and third rows such as those containing Ru, Rh, Os, and Ir are especially active during HDS reactions.27 Similarly, sulfides of Ir, Os, and Re were found to be most active in the HDN of quinoline,28 and sulfides of Ir and Pt were found to be most active in the HDN of pyridine.29 However, catalytic properties of metal deposited on alumina or other supports have been studied less frequently, and moreover, the primary attention to date has been devoted only to Ru.30 It was shown by Cinibulk and Vit́31 that the HDN of higher pressures and temperatures to obtain desired conversions. Therefore, the need for more active catalysts is crucial in this process. The development of highly active and selective hydrotreating catalysts is one of the most pressing problems facing the petroleum indu
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    Hydrogenation of tetralin over Ir-TI02/SBA-16
    (Universidad Tecnológica Nacional, 2013) Ledesma, Brenda; Valles , Verónica; Martínez , Maria Laura; Anunziata, Oscar Alfredo; Beltramone , Andrea Raquel
    A titanium modified catalyst based on noble metal has been prepared with the main aim of obtaining thiotolerant catalysts to be used in second stage processes of mild-hydrotreating. We study the catalytic properties of 1 wt% Ir-containing mesoporous materials modified with TiO2 in the hydrogenation of tetralin to decalin in the presence of 100 ppm of dibenzotiophene at 250°C and 15 atm of pressure of hydrogen, using a Parr reactor. Titanium oxide was added via post synthesis with the purpose of improve iridium dispersion. Ir/mesoporous materials were prepared by wetness impregnation. The catalyst synthesized by us had good activity measured in tetralin hydrogenation at mild conditions. The preliminary results show these materials as a promising catalyts for HDS/HDN reactions.
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    Inhibition of the hydrogenation of tetralin by nitrogen and sulfur compounds over Ir/SBA-16
    (2011) Balangero, Gerardo Simón; Martínez, María Laura; Gómez Costa, Marcos Bruno; Anunziata, Oscar Alfredo; Beltramone, Andrea Raquel
    In this work we study the catalytic properties of 5 wt.% Ir-containing SBA-16 catalysts (with and without aluminum as heteroatom), in the hydrogenation of tetralin to decalin, in the presence of 100 ppm of N as quinoline, indole and carbazole, and 100 ppm of S as dibenzothiophene and 4,6-dimethyl- dibenzothiophene at 250 ◦C and 15 atm of pressure of hydrogen, using a Parr reactor. Ir/SBA-16 and Ir/Al-SBA-16 were prepared by wetness impregnation using Iridium Acetylacetonate as source of Ir. The Ir/SBA-16 catalyst synthesized by us had high activity measured in tetralin hydrogenation at mild con- ditions. The experimental data was quantitatively represented by a modified Langmuir–Hinshelwood type rate equation, using the apparent adsorption constants calculated from the inhibition results for the individual compounds. The catalyst showed a good resistance to sulfur and nitrogen compounds. The inhibiting effect increased in the order: DBT < quinoline < 4,6-dimethyl-DBT < indole < carbazole. The inhibiting effect of the nitrogen/sulfur compounds was strong, but the activity was still higher than with commercial NiMo/alumina catalyst. We present in this contribution a successfully developed, high loaded and well dispersed Ir/SBA-16 catalysts, that have been shown to maintain a useful catalytic activity, even in the presence of relatively high amounts of sulfur compounds (up to 100 ppm, sulfur basis). Consequently, economically successful processes have evolved, based on this class of catalysts.
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    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
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    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