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Study on preparation of a vovel silica adsorbent and its selective separation applied to genistein

Zhang,Yuqing; Zhang,Yahui; Zhang,Hongliu
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2008 EN
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In order to selectively separate genistein from its crude solution, a novel silica adsorbent was prepared using genistein as the template molecule, gamma-aminopropylthriethoxysilane as the functional monomer and tetraethyl orthosilicate as the cross-linker. It was analyzed by the BET, FTIR, TEM characteristics, the static adsorption experiment, and selective adsorption experiment. The results show that the silica adsorbent has high specific area, special selectivity and high adsorption capacity for genistein. It can recognize and bind genistein in aqueous solution, and lots of nanopores distribute on its surface uniformly. It is concluded that both the shape and size of the recognition sites matching the template molecule result in the performance of this adsorbent to bind genistein and that there are strong ionic and hydrogen bond attractions between the phenolic hydroxyl and the -NH2.

Pineapple fruit bromelain recovery using recyclable functionalized ordered mesoporous silica synthesized from sugarcane leaf ash

Arumugam,A.; Ponnusami,V.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2013 EN
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Bromelain, a protease enzyme found in Ananas comosus (Pineapple), was recovered from the fruit juice by adsorption using recyclable functionalized Santa Barbara Acid-15 (SBA-15) synthesized from sugarcane leaf ash. In this work, highly ordered mesoporous silica was synthesized from sugarcane leaf ash by a template-assisted method. It was successfully used as an adsorbent for the recovery of bromelain from pineapple fruit pulp. Amine-functionalized mesoporous silica exhibited a recovery efficiency of 97.89% and a 6.2-fold purification. It was also established that the adsorbent could be easily regenerated by adjusting the pH. In this study, the adsorbent was reused for three cycles without noticeable loss in recovery efficiency. Thus, adsroption using functionalized SBA-15 appears to be a promising alternate separation technique for the recovery of fruit bromelain.

Estudo comparativo do desempenho mecânico da sílica ativa e do metacaulim como adições químicas minerais em estruturas de concreto

Carmo,J. B. M. do; Portella,K. F.
Fonte: Associação Brasileira de Cerâmica Publicador: Associação Brasileira de Cerâmica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2008 PT
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Neste trabalho foram realizados estudos comparativos entre um concreto convencional e concretos contendo sílica ativa e metacaulim de alta reatividade (MCAR). O desempenho dos mesmos foi testado em termos das resistências à compressão e à tração por compressão diametral. Análises de custo foram efetuadas comparativamente, em função da resistência à compressão, do consumo de materiais cimentícios e, também, do preço do produto no mercado brasileiro. Os consumos totais de materiais cimentícios estudados estiveram compreendidos entre 180 kg/m³ e 650 kg/m³. O uso de 8% em peso de MCAR e de sílica ativa em relação à massa de cimento, foi suficiente para inibir as reações álcali-agregado verificadas no concreto convencional. O uso de ambas as adições proporcionou ganhos em termos de resistência e de custo nas primeiras idades (90 dias), sendo, praticamente equivalentes entre si.

Características da sílica coloidal e seus efeitos em concretos refratários

Magliano,M. V. M; Pandolfelli,V. C
Fonte: Associação Brasileira de Cerâmica Publicador: Associação Brasileira de Cerâmica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2010 PT
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A sílica coloidal se apresenta como um promissor substituto do cimento de aluminato de cálcio para utilização em concretos mulitizáveis. O uso deste ligante promove adequada resistência mecânica a verde, facilidade de secagem, inibe a formação de fases de baixo ponto de fusão, além de favorecer a formação de mulita in-situ. Entretanto, as propriedades finais do concreto dependem das características da solução coloidal utilizada. O objetivo deste trabalho é comparar as propriedades a verde e a quente de sistemas mulitizáveis ligados por sílica coloidal, variando suas características, tais como teor de sólidos, área superficial e tipo de estabilizante. Os resultados indicaram que sílicas coloidais com alta área superficial reduzem a trabalhabilidade dos concretos e diminuem as propriedades a quente devido ao acentuado trincamento durante a cura. A refratariedade dos sistemas é ainda comparada com concretos ligados por cimento de aluminato de cálcio e alumina hidratável, ressaltando a superioridade do ligante coloidal.

Effect of divalent chloride salts on lamellar silica conductivity

Araujo,A. C. P. C. de; Cavalcante,M. G.
Fonte: Associação Brasileira de Cerâmica Publicador: Associação Brasileira de Cerâmica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2013 EN
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Silica is an important raw material in the production of soluble silicates, silicon and its derivatives: silicon carbide and silicone, which are converted into the lamellar form using the sol-gel process. This compound, which has been extensively studied because it is structurally organized, can be used for selective adsorption of toxic substances or immobilization of photo-active species. Impedance spectroscopy was used in a study of the electrical properties of lamellar silica doped with the following metal salts: nickel chloride, manganese chloride, and copper chloride, in order to observe the cation effect in their structure. In this study, the following order of conductivity was obtained: manganese chloride nickel chloride copper chloride. This effect was also observed using X-ray diffraction analysis.

Método de extração de sílica da casca do arroz

Fernandes,L.; Sabino,M. G.; Rossetto,H. L.
Fonte: Associação Brasileira de Cerâmica Publicador: Associação Brasileira de Cerâmica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2014 PT
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A influência dos ácidos cítrico, acético e oxálico na extração da sílica a partir da casca do arroz foi estudada. As condições experimentais da extração, como pressão e concentração ácida, também foram estudadas. De acordo com o tamanho dos poros pela adsorção de N2, conforme método BET, foram classificadas como mesoporosa. Comparações entre diferentes tipos de ácidos utilizados foram realizadas pela área de superfície específica da sílica obtida.O ácido que apresentou melhor desempenho foi o acético, resultando em área de superfície específica 271 m²/g; o ácido cítrico apresentou o melhor resultado de pureza, 99,96%.

Influence of processing variables on the pore structure of silica gels obtained with tetraethylorthosilicate

Silva,Rúbia F.; Vasconcelos,Wander L.
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/1999 EN
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Received: August 15, 1998; Revised: March 30, 1999 In this work it was evaluated the influence of the type and concentration of the acid catalyst and the gelation temperature on the structure of pores of silica gels obtained with TEOS. The values of the major structural parameters related to the pores such as volume fraction of pore (VV), surface area per unit volume (SV), the average pore size (rP) and the connectivity of pores (GV), obtained in this work showed the possibility of tailoring the pore structure of silica gels by changing the processing variables. For the HF catalyzed gels the values of average pore radius varied from 6.8 nm to 21.6 nm, and the gelation time varied from 2 min to 140 min. For the gels obtained in this work the activation energy for gelation (E) was found to be 11.8 kcal/mole.

Preparation of silica by sol-gel method using formamide

Lenza,R.F.S.; Vasconcelos,W.L.
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2001 EN
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In this work we obtained microporous and mesoporous silica gels by sol-gel processing. Tetraethylortosilicate (TEOS) was used as precursor. Nitric acid and hydrofluoric acid were used as catalysts. In order to study the affect of formamide as drying additive, we used a molar ratio alkoxide/formamide of 1/1. The performance of formamide in obtaining crack-free gels was evaluated through monolithicity measurements. The structural evolution occurring in the interconnected network of the gels during thermal treatment was monitored by Fourier transform infrared spectroscopy (FTIR), shrinkage and density measurements and nitrogen gas sorption. We noted that in the presence of formamide, the Si-O-Si bonds are stronger and belong to a more cross-linked structure. The samples obtained in the presence of formamide have larger pore volume and its pore structure is in the range of mesoporosity. The samples obtained without additive are microporous. Formamide allowed the preparation of crack-free silica gels stabilized at high temperatures.

Europium incorporated in silica matrix obtained by sol-gel: luminescent materials

Nassar,Eduardo José; Ciuffi,Katia Jorge; Ribeiro,Sidney José Lima; Messaddeq,Younes
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2003 EN
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In this work we report some aspects of the chemistry involved in the preparation of modified silicon oxide by the sol-gel process. Europium III compounds were used as luminescent probe. An organic-inorganic hybrid was obtained by hydrolysis of tetraethylorthosilicate (TEOS) and 3-aminopropyltriethoxysilane (APTS). The Eu III compounds were added in different ways. In the first, silica was prepared in the presence of Eu III, and in the second, Eu III was added on the silica surface. These materials were studied by luminescence, infrared spectroscopy and termogravimetric analysis. The results obtained for the hybrid material show different behavior for Eu III emission, which could be excited by the antenna effect and the influence of the surrounding in the luminescence quenching. The thermogravimetric data present different mass loss in samples to range temperature 50 - 150 °C. Thermogravimetric and infrared spectra showed that inorganic polymers incorporated the organic part.

Rheological and mechanical characterization of poly (methyl methacrylate)/silica (PMMA/SiO2) composites

Silva,Erik dos Santos; Ribeiro,Lourdes Aparecida; Nascimento,Maria Carolina Burgos Costa do; Ito,Edson Noriyuki
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2014 EN
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The search for new materials with properties suitable for specific applications has increased the number of research studies to fill the market demands. The development of polymer composites by the addition of inorganic fillers to the poly(methyl methacrylate) (PMMA) increases the potential use of this polymer in various application fields. The main objective of this work was to study the rheological and mechanical behavior of composites obtained from the addition of silica in two different types of PMMA matrix: a common (PMMAc) and an elastomeric copolymer (PMMAel). The results showed that the addition of silica particles to the PMMA matrix promoted an increase in torque, a decrease in the melt flow index of composites and an increase in hardness compared to pure polymers. The composites also showed a reduction of the maximum tensile strength for composites with PMMAc matrix and maintenance of tensile strength for composites with PMMAel matrix. The average width of scratch decreased due to a change in wear mechanism, attributed to the increase of hardness in the composites obtained.

Relação entre a resistência à compressão da argamassa com adição de sílica ativa aplicada ao substrato e àquela obtida em corpos-de-prova cilíndricos normatizados

Vaske,N. R.; Campagnolo,J. L.; Dal Molin,D. C. C.
Fonte: IBRACON - Instituto Brasileiro do Concreto Publicador: IBRACON - Instituto Brasileiro do Concreto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2010 PT
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No uso de argamassa com adição de sílica ativa como material de reforço adotam-se valores de resistência à compressão provenientes de ensaios normatizados, que tendem a não representar a resistência à compressão da argamassa após lançada ao substrato. Na execução de um reforço, cada porção de argamassa que é lançada sofre um adensamento que varia em função da energia com que colide com o substrato, gerando, desta forma, pontos de diferentes resistências à compressão por toda a extensão do reforço, refletindo diretamente sobre a resistência do reforço como um todo, que por sua vez define a nova capacidade de carga do elemento estrutural que esta sendo reforçado. Procurando verificar o comportamento real da argamassa de reforço, executou-se uma placa de argamassa com adição de sílica ativa com dimensões iguais a um reforço de uma das faces de um pilar, sendo extraídas amostras prismáticas desta placa e ensaiadas à compressão. Deste ensaio foi de- terminada uma resistência à compressão média que, comparada com a resistência à compressão média obtida de corpos-de-prova cilíndricos, moldados com a mesma argamassa com que foi executada a placa, demonstrou que a resistência à compressão média das amostras prismáticas extraídas da placa apresenta...

Chloride accelerated test: influence of silica fume, water/binder ratio and concrete cover thickness

Pereira,E.; Resende,A.; Medeiros,M. H. F. de; Meneghetti,L. C.
Fonte: IBRACON - Instituto Brasileiro do Concreto Publicador: IBRACON - Instituto Brasileiro do Concreto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2013 EN
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In developed countries like the UK, France, Italy and Germany, it is estimated that spending on maintenance and repair is practically the same as investment in new constructions. Therefore, this paper aims to study different ways of interfering in the corrosion kinetic using an accelerated corrosion test - CAIM, that simulates the chloride attack. The three variables are: concrete cover thickness, use of silica fume and the water/binder ratio. It was found, by analysis of variance of the weight loss of the steel bars and chloride content in the concrete cover thickness, there is significant influence of the three variables. Also, the results indicate that the addition of silica fume is the path to improve the corrosion protection of low water/binder ratio concretes (like 0.4) and elevation of the concrete cover thickness is the most effective solution to increase protection of high water/binder ratio concrete (above 0.5).

Factors Affecting Survival of the Merchant Grain Beetle (Coleoptera: Cucujidae) and the Confused Flour Beetle (Coleoptera: Tenehrionidae) Exposed to Silica Aerogel

White, N. D. G.; Loschiavo, S. R.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica Formato: text/html
EN
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Mortality of Oryzaephilus mercator Fauvel exposed to 0.72 mg/cm2 silica aerogel (SG-67) bound to paper was directly related to length of exposure of the insects and length of time between exposure and placement in food. Exposures of 15 skilled 97% of starved adults in 2 d, but mortality was low if adults had access to food within 2 h. As exposure times increased, insects survived only if food was available at shorter intervals. Type and quantity of food also affected mortality. Mortality of O. mercator adults exposed to SG-67 was greater on bread crumbs and whole rolled oats than on ground rolled oats. Starved Tribolium confusum Jacquelin du Val required exposures of 6 h to SG-67 for complete mortality; the presence of food following exposure, rather than type or quantity, affected survival, although mortality was slightly higher on bread crumbs. Early larval instars of O. mercator and T. confusum were more susceptible than late instars, which responded to SG-67 in the same way as adults. Adults of both species exposed to SG-67 and subsequently held in inert cellulose powder died within 1-3 d, but many insects in ground rolled oats survived, probably because they had ingested and metabolized food and produced metabolic water. Adult O. mercator immobilized at 2.5°C during exposure to SG-67 for 4 h...

Sensor for fisetin based on gold nanoparticles in ionic liquid and binuclear nickel complex immobilized in silica

Brondani, Daniela; Vieira, Iolanda Cruz; Piovezan, Clovis; Silva, Jaqueline Maria Ramos da; Neves, Ademir; Dupont, Jairton; Scheeren, Carla Weber
Fonte: Universidade Federal do Rio Grande Publicador: Universidade Federal do Rio Grande
Tipo: Artigo de Revista Científica
ENG
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Gold nanoparticles dispersed in an ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (Au-BMI.PF6) and a binuclear nickel(II) complex ([Ni2(HBPPAMFF)??-(OAc)2(H2O)]BPh4) immobilized on functionalized silica were successfully applied in the construction of a novel sensor for the determination of fisetin by square-wave voltammetry. Under optimized conditions, the analytical curve showed two linear ranges for fisetin concentrations from 0.28 to 1.39 ??M and 2.77 to 19.50 ??M with a detection limit of 0.05 ??M. This sensor demonstrated suitable stability (ca. 150 days; at least 500 determinations) and good repeatability and reproducibility, with relative standard deviations of 2.91 and 5.11%, respectively. The recovery study of fisetin in apple juice samples gave values from 96.4 to 106.4%. The efficient analytical performance of the proposed sensor can be attributed to the effective immobilization of the NiIINiII complex on silica and the Au-BMI.PF6 contribution to the electrode response.

Instrumentação para espectroscopia de modos ópticos com alto fator de qualidade em microesferas de sílica

Lucas Siqueira de Lima e Silva, Rodolfo; de Souza Menezes, Leonardo (Orientador)
Fonte: Universidade Federal de Pernambuco Publicador: Universidade Federal de Pernambuco
Tipo: Outros
PT_BR
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Neste trabalho, realizou-se a instrumentação eletrônica de um laser de diodo sintonizável com cavidade estendida para espectroscopia no visível dos automodos de microesferas de sílica. Para isto, é desejável desenvolver uma fonte de luz sintonizável por alguns GHz, apresentando uma largura de linha máxima de 1 MHz, já que o intervalo espectral livre das microcavidades de interesse é de poucas centenas de GHz e as suas ressonâncias ópticas são muito estreitas ( 10 MHz). Esta ferramenta é um laser de diodo sintonizável, montado com uma cavidade externa, em uma configuração tipo Littrow. Foi necessário construir um circuito eletrônico para estabilizar a corrente e a temperatura do laser de diodo e instalá-lo em uma montagem mecânica que permite o estreitamento da largura de linha do laser, assim como a varredura do seu comprimento de onda, sem salto de modos, no maior intervalo possível. Para realizar a caracterização do laser, foi projetado e construído um interferômetro Fabry-Perot confocal. Para fabricar as microesferas, é utilizado um laser de CO2 para derreter um pedaço de fibra óptica de telecomunicações, colado dentro de um túbulo de cobre. Ao absorver a energia do laser, a sílica derrete e...

Éteres coroa com íons lantanídeos: de compostos de coordenação a novos materiais nanoestruturados de sílica

Freire Belian, Mônica; Alves Junior, Severino (Orientador)
Fonte: Universidade Federal de Pernambuco Publicador: Universidade Federal de Pernambuco
Tipo: Outros
PT_BR
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Com o objetivo de desenvolver novos materiais e ligantes, baseados em éteres coroa, capazes de coordenarem um ou mais íons lantanídeos, o presente trabalho mostra a síntese de compostos de coordenação mono e binucleares, livres ou ligados às matrizes de sílica. As caracterizações foram realizadas via análise elementar, análise termogravimétrica, espectroscopia na região do infravermelho e ultravioleta, ressonância magnética nuclear de 1H e 13C. Um estudo minucioso, acerca dos compostos inéditos sintetizados, mostrou a necessidade da substituição das moléculas de água (1a esfera de coordenação) por ligantes heterobi(tri)aris (bipiridina, fenantrolina e terpiridina); esses bem descritos na literatura, geralmente otimizam o processo de luminescência. Os dados de análise elementar (experimentais e teóricos) dos compostos sintetizados apresentaram boa concordância; confirmando assim, as fórmulas mínimas propostas. Os dados da espectroscopia na região do ultravioleta e infravermelho corroboraram para intuir que os ligantes encontram-se coordenados aos íons lantanídeos. A espectroscopia de luminescência, para os compostos de coordenação, mostrou que os sistemas mononucleares apresentam maior intensidade de luminescência quando comparados aos binucleares e às matrizes de sílica. Apenas o sistema NanoSilTb apresentou intensa luminescência...

Fluorescent compacts prepared by the entrapment of benzoxazole type dyes into a silica matrix at high pressure

Costa, Tânia Maria Haas; Stefani, Valter; Jornada, João Alziro Herz da
Fonte: Inmetro - Instituto Nacional de Metrologia, Qualidade e Tecnologia Publicador: Inmetro - Instituto Nacional de Metrologia, Qualidade e Tecnologia
Tipo: Artigo de Revista Científica
ENG
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5 p. : il.; We have produced silica-gel compacts doped with 2,5-Bis(benzoxazol-2´-yl)-4-methoxyphenol dye using high-pressure processing of powders synthesized by the sol–gel technique. The high-pressure compaction of powders with three different dye concentrations was done at 4.5 GPa and room temperature. We have measured optical and mechanical properties of the obtained compacts. They were very stable, transparent, crack free, hard (3.56 ± 0.07 GPa) and dense (1.95 ± 0.03 g/cm3), being resistant to polishing and leaching, which enables its use in optical applications. The Stokes shift observed was higher than 100 nm indicating that the intramolecular proton-transfer in the electronically excited state (ESIPT) of this dye is maintained, even in an OH rich environment like silica. A shift to higher wavelength in the fluorescence spectra of the compacts, attributed to the increasing in the conjugation of the pi system, was observed.

Phosphine-stabilised Au9 clusters interacting with titania and silica surfaces: The first evidence for the density of states signature of the support-immobilised cluster; The Journal of Chemical Physics

Andersson, Gunther G.; Golovko, Vladimir B.; Alvino, Jason F.; Bennett, Trystan; Wrede, Oliver; Mejia, Sol M.; Al Qahtani, Hassan S.; Adnan, Rohul; Gunby, Nathaniel; Anderson, David P.; Metha, Gregory F.
Fonte: Pontifícia Universidade Javeriana Publicador: Pontifícia Universidade Javeriana
Formato: 1 -12
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Vol. 141, no. 1; Chemically made, atomically precise phosphine-stabilized clusters Au9(PPh3)8(NO3)3 were deposited on titania and silica from solutions at various concentrations and the samples heated under vacuum to remove the ligands. Metastable induced electron spectroscopy was used to determine the density of states at the surface, and X-ray photoelectron spectroscopy for analysing the composition of the surface. It was found for the Au9 cluster deposited on titania that the ligands react with the titania substrate. Based on analysis using the singular value decomposition algorithm, the series of MIE spectra can be described as a linear combination of 3 base spectra that are assigned to the spectra of the substrate, the phosphine ligands on the substrate, and the Au clusters anchored to titania after removal of the ligands. On silica, the Au clusters show significant agglomeration after heat treatment and no interaction of the ligands with the substrate can be identified.

Functionalized diatom silica microparticles for removal of mercury ions

Yu, Y.; Addai-Mensah, J.; Losic, D.
Fonte: Institute of Physics Publishing Ltd Publicador: Institute of Physics Publishing Ltd
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
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Diatom silica microparticles were chemically modified with self-assembled monolayers of 3-mercaptopropyl-trimethoxysilane (MPTMS), 3-aminopropyl-trimethoxysilane (APTES) and n-(2-aminoethyl)-3-aminopropyl-trimethoxysilane (AEAPTMS), and their application for the adsorption of mercury ions (Hg(II)) is demonstrated. Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy analyses revealed that the functional groups (–SH or –NH2) were successfully grafted onto the diatom silica surface. The kinetics and efficiency of Hg(II) adsorption were markedly improved by the chemical functionalization of diatom microparticles. The relationship among the type of functional groups, pH and adsorption efficiency of mercury ions was established. The Hg(II) adsorption reached equilibrium within 60 min with maximum adsorption capacities of 185.2, 131.7 and 169.5 mg g-1 for particles functionalized with MPTMS, APTES and AEAPTMS, respectively. The adsorption behavior followed a pseudo-second-order reaction model and Langmuirian isotherm. These results show that mercapto- or amino-functionalized diatom microparticles are promising natural, cost-effective and environmentally benign adsorbents suitable for the removal of mercury ions from aqueous solutions.; Yang Yu...

Mesoporous silica nanoparticles act as a self-adjuvant for ovalbumin model antigen in mice

Mahony, D.; Cavallaro, A.; Stahr, F.; Mahony, T.; Qiao, S.; Mitter, N.
Fonte: Wiley - VCH Verlag GmbH & Co KGaA Publicador: Wiley - VCH Verlag GmbH & Co KGaA
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
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Immunization to the model protein antigen ovalbumin (OVA) is investigated using MCM-41 mesoporous silica nanoparticles as a novel vaccine delivery vehicle and adjuvant system in mice. The effects of amino surface functionalization and adsorption time on OVA adsorption to nanoparticles are assessed. Amino-functionalized MCM-41 (AM-41) shows an effect on the amount of OVA binding, with 2.5-fold increase in binding capacity (72 mg OVA/g AM-41) compared to nonfunctionalized MCM-41 (29 mg OVA/g MCM-41). Immunization studies in mice with a 10 μg dose of OVA adsorbed to AM-41 elicits both antibody and cell-mediated immune responses following three subcutaneous injections. Immunizations at a lower 2 μg dose of OVA adsorbed to AM-41 particles results in an antibody response but not cell-mediated immunity. The level of antibody responses following immunization with nanoformulations containing either 2 μg or 10 μg of OVA are only slightly lower than that in mice which receive 50 μg OVA adjuvanted with QuilA, a crude mixture of saponins extracted from the bark of the Quillaja saponaria Molina tree. This is a significant result, since it demonstrates that AM-41 nanoparticles are self-adjuvanting and elicit immune responses at reduced antigen doses in vivo compared to a conventional delivery system. Importantly...