Estudos biológicos de nanopartículas de óxido de zinco: interação com proteínas e avaliação de “Burst” oxidativo de leucócitos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito in vivo da deposição de filmes de DLC com e sem nanopartículas de prata sobre liga de titânio para utilização em próteses articulares

Pós-graduação em Biopatologia Bucal - ICT

Nanopartículas magnéticas como suporte para imobilização de lipases

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Nanopartículas de prata e glicerofosfato de cálcio: sínteses por rotas convencionais e fitoquímica, análise antimicrobiana e avaliação da citotoxicidade

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Filmes de borracha natural com nanopartículas de prata e pontos quânticos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Incorporação de nanopartículas de óxido de zinco a um cimento de ionômero de vidro por meio da calcinação: avaliação de propriedades mecânicas e físicas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Nanopartículas de Pd suportadas em compósitos óxido-carbono: influência das interações metal-suporte na oxidação de etanol em meio básico

Fuel cells powered directly with ethanol (Direct Ethanol Fuel Cell-DEFC) are very attractive for the possibility of using a renewable fuel in the generation of clean energy. However, it is still necessary to deepen the understanding of catalytic processes and their dependence on the catalytic properties. This work proposes to study the catalytic activity of ethanol oxidation in an alkaline medium of Pd nanoparticles supported in carbon oxide hybrids using various transition metal oxides (MoO3, TiO2, WO3 and ZrO2). The materials prepared were characterized by techniques such as X-ray diffraction, transmission electron microscopy (TEM) and X-ray dispersive spectroscopy (EDX) to verify the structure, the distribution of particles in the supports and the presence of Pd on particles oxide. Experiments of X-rays absorption spectroscopy were carried out using soft X-rays (SXS) to evaluate the changes in the electronic properties of the Pd particles caused by interactions with different oxides. Measurements of cyclic voltammetry and potential sweeps of adsorbed CO oxidation allowed evaluating general aspects of the catalysts' electrochemical behavior and determining the electrochemically active area thereof. The catalytic performances of ethanol oxidation in alkaline medium were evaluated by electrochemical techniques (potential scan and chronoamperometry), and showed an improvement in activity with the addition of oxides in material containing only carbon, which was most pronounced for the catalyst containing TiO2. This improvement was predominantly associated with the electronic effects caused by the interaction of Pd on the support, causing a vacancy in the 4d band of Pd which, in turn, produces variations in adsorption energies of the species...

Nanopartículas de CeO2 modificadas com Er obtidas pelo método hidrotermal microondas: estudo fotoluminescente

The development of nanostructured materials have aroused great interest of the industries all over the country, since they enable the development of devices that can be used as gate insulators on silicon transistors, electrochromic devices, solid electrolyte oxygen sensors and as a photoluminescent materials . In this project, it is proposed to investigate the optical properties of CeO2 modified with rare earth Er processed in hydrothermal-microwave. The synthesis of one-dimensional nanostructures (1D) was measured from dilute aqueous solutions of acids and salts of starting reagents in the presence of chemical basis, after these aqueous solutions were processed on hydrothermal-microwave to particle growth. The particles obtained after processing were characterized by X-ray Diffraction, Rietveld Analysis and Raman Spectroscopy. The particle morphology was observed by scanning electron microscopy with field emission gun. The synthesis of 1D nanostructures are evaluated for different surfactants and starting precursors (ceria different salts), pH, temperature and pressure which can modify the morphology of the nanostructures. Combining laboratory experiments and theoretical calculations it was desired to understand the organization of the nanoparticles and their resulting structure. Strict control of chemical homogeneity, crystal structure, microstructure and interaction of the CeO2 cluster with different surfactants using the Hartree-Fock method, was intended to obtain properties compatible with their use in catalysts and optical devices. The use of mineralizer agent KOH and 8 minutes of processing time synthesis conditions were chosen to evaluate the effect of Er dopant. It has been proved that this doping with rare earth increases the photoluminescent properties of the compound obtained without change the structural and morphological propreties of ceria

Nanopartículas à base de óxido de zinco dopadas com magnésio e com superfície modificada para aplicação em bioimagem

O diagnóstico precoce de diversas doenças, principalmente o câncer, é fundamental para o seu combate. Atualmente, muitos avanços têm sido feitos na área de nanotecnologia no sentido de desenvolver sistemas com aplicação na área biomédica e em bioimagem para o diagnóstico de doenças. Nesse contexto, nano-cristais semicondutores de ZnO apresentam elevado potencial como marcadores para aplicações biológicas devido á suas propriedades luminescentes. A fotoluminescência de pontos quânticos (PQs) de ZnO envolve dois aspectos: a emissão excitônica fraca na região do UV e a ampla emissão visível induzida por efeito da superfície PQ. Estudos sinalizam que na síntese de nanopartículas de ZnO, a introdução de magnésio (Mg) como dopante leva a uma mudança significativa no tamanho e forma dos nano-cristais, potencializando as propriedades de luminescência. Entretanto, ainda é um desafio para os pesquisadores obter nanopartículas de ZnO aptas a serem incorporados em nanocarreadores e que sejam estáveis em meio biológico. Desta forma, este trabalho, apresenta como objetivo principal a obtenção de pontos quânticos de ZnO dopados com Mg e recobertos com ácido cítrico e 3-Glycidilpropriltrimetóxisilano (GPTMS) como modificadores de superfície para prover estabilidade em meio biológico. Eles poderão posteriormente ser incorporados em sistemas carreadores a fim de constituir sistemas estáveis com potencialização das propriedades luminescentes dos PQs e, portanto, aptos para aplicação como material de diagnóstico em sistemas biológicos

Nanopartículas de Pd suportadas em compósitos óxido-carbono: influência das interações metal-suporte na oxidação de etanol em meio básico

Fuel cells powered directly with ethanol (Direct Ethanol Fuel Cell-DEFC) are very attractive for the possibility of using a renewable fuel in the generation of clean energy. However, it is still necessary to deepen the understanding of catalytic processes and their dependence on the catalytic properties. This work proposes to study the catalytic activity of ethanol oxidation in an alkaline medium of Pd nanoparticles supported in carbon oxide hybrids using various transition metal oxides (MoO3, TiO2, WO3 and ZrO2). The materials prepared were characterized by techniques such as X-ray diffraction, transmission electron microscopy (TEM) and X-ray dispersive spectroscopy (EDX) to verify the structure, the distribution of particles in the supports and the presence of Pd on particles oxide. Experiments of X-rays absorption spectroscopy were carried out using soft X-rays (SXS) to evaluate the changes in the electronic properties of the Pd particles caused by interactions with different oxides. Measurements of cyclic voltammetry and potential sweeps of adsorbed CO oxidation allowed evaluating general aspects of the catalysts' electrochemical behavior and determining the electrochemically active area thereof. The catalytic performances of ethanol oxidation in alkaline medium were evaluated by electrochemical techniques (potential scan and chronoamperometry), and showed an improvement in activity with the addition of oxides in material containing only carbon, which was most pronounced for the catalyst containing TiO2. This improvement was predominantly associated with the electronic effects caused by the interaction of Pd on the support, causing a vacancy in the 4d band of Pd which, in turn, produces variations in adsorption energies of the species...

Nanopartículas de CeO2 modificadas com Er obtidas pelo método hidrotermal microondas: estudo fotoluminescente

The development of nanostructured materials have aroused great interest of the industries all over the country, since they enable the development of devices that can be used as gate insulators on silicon transistors, electrochromic devices, solid electrolyte oxygen sensors and as a photoluminescent materials . In this project, it is proposed to investigate the optical properties of CeO2 modified with rare earth Er processed in hydrothermal-microwave. The synthesis of one-dimensional nanostructures (1D) was measured from dilute aqueous solutions of acids and salts of starting reagents in the presence of chemical basis, after these aqueous solutions were processed on hydrothermal-microwave to particle growth. The particles obtained after processing were characterized by X-ray Diffraction, Rietveld Analysis and Raman Spectroscopy. The particle morphology was observed by scanning electron microscopy with field emission gun. The synthesis of 1D nanostructures are evaluated for different surfactants and starting precursors (ceria different salts), pH, temperature and pressure which can modify the morphology of the nanostructures. Combining laboratory experiments and theoretical calculations it was desired to understand the organization of the nanoparticles and their resulting structure. Strict control of chemical homogeneity, crystal structure, microstructure and interaction of the CeO2 cluster with different surfactants using the Hartree-Fock method, was intended to obtain properties compatible with their use in catalysts and optical devices. The use of mineralizer agent KOH and 8 minutes of processing time synthesis conditions were chosen to evaluate the effect of Er dopant. It has been proved that this doping with rare earth increases the photoluminescent properties of the compound obtained without change the structural and morphological propreties of ceria

Nanopartículas à base de óxido de zinco dopadas com magnésio e com superfície modificada para aplicação em bioimagem

O diagnóstico precoce de diversas doenças, principalmente o câncer, é fundamental para o seu combate. Atualmente, muitos avanços têm sido feitos na área de nanotecnologia no sentido de desenvolver sistemas com aplicação na área biomédica e em bioimagem para o diagnóstico de doenças. Nesse contexto, nano-cristais semicondutores de ZnO apresentam elevado potencial como marcadores para aplicações biológicas devido á suas propriedades luminescentes. A fotoluminescência de pontos quânticos (PQs) de ZnO envolve dois aspectos: a emissão excitônica fraca na região do UV e a ampla emissão visível induzida por efeito da superfície PQ. Estudos sinalizam que na síntese de nanopartículas de ZnO, a introdução de magnésio (Mg) como dopante leva a uma mudança significativa no tamanho e forma dos nano-cristais, potencializando as propriedades de luminescência. Entretanto, ainda é um desafio para os pesquisadores obter nanopartículas de ZnO aptas a serem incorporados em nanocarreadores e que sejam estáveis em meio biológico. Desta forma, este trabalho, apresenta como objetivo principal a obtenção de pontos quânticos de ZnO dopados com Mg e recobertos com ácido cítrico e 3-Glycidilpropriltrimetóxisilano (GPTMS) como modificadores de superfície para prover estabilidade em meio biológico. Eles poderão posteriormente ser incorporados em sistemas carreadores a fim de constituir sistemas estáveis com potencialização das propriedades luminescentes dos PQs e, portanto, aptos para aplicação como material de diagnóstico em sistemas biológicos

Monitoramento in vivo por imagem por ressonância magnética de células C6 de glioma marcadas com nanopartículas superparamagnéticas de óxido de ferro

OBJECTIVE: The aim of the current study was to monitor the migration of superparamagnetic iron oxide nanoparticle (SPION)-labeled C6 cells, which were used to induce glioblastoma tumor growth in an animal model, over time using magnetic resonance imaging (MRI), with the goal of aiding in tumor prognosis and therapy. METHODS: Two groups of male Wistar rats were used for the tumor induction model. In the first group (n=3), the tumors were induced via the injection of SPION-labeled C6 cells. In the second group (n=3), the tumors were induced via the injection of unlabeled C6 cells. Prussian Blue staining was performed to analyze the SPION distribution within the C6 cells in vitro. Tumor-inducing C6 cells were injected into the right frontal cortex, and subsequent tumor monitoring and SPION detection were performed using T2- and T2*-weighted MRI at a 2T field strength. In addition, cancerous tissue was histologically analyzed after performing the MRI studies. RESULTS: The in vitro qualitative evaluation demonstrated adequate distribution and satisfactory cell labeling of the SPIONs. At 14 or 21 days after C6 injection, a SPION-induced T2- and T2*-weighted MRI signal reduction was observed within the lesion located in the left frontal lobe on parasagittal topography. Moreover, histological staining of the tumor tissue with Prussian Blue revealed a broad distribution of SPIONs within the C6 cells. CONCLUSION: MRI analyses exhibit potential for monitoring the tumor growth of C6 cells efficiently labeled with SPIONs.

Caracterización de nanopartículas magnéticas y de oro para posibles aplicaciones biomédicas en diagnóstico y terapia

Los nanomateriales han adquirido recientemente un gran interés debido a la gran variedad de aplicaciones que pueden llegar a tener en el ámbito de la biomedicina. Este trabajo recoge las posibilidades tanto diagnósticas como terapéuticas que presentan dos modalidades de nanomateriales: nanopartículas de óxido de hierro y nanopartículas de oro. Para ello, en una primera aproximación se ha llevado a cabo la caracterización de las nanopartículas desde el punto de vista de la biocompatibilidad asociada a su tamaño y al tiempo de contacto o circulación en células y tejidos, ensayada tanto in vitro como in vivo así como la cinética de acumulación de dichas nanopartículas en el organismo vivo. Posteriormente se ha realizado la biofuncionalización de los dos tipos de nanopartículas para reconocer dianas moleculares específicas y poder ser utilizadas en el futuro en dos aplicaciones biomédicas diferentes: diagnóstico de enfermedad de Alzheimer mediante imagen de resonancia magnética y destrucción selectiva de células tumorales mediante hipertermia óptica. ABSTRACT Nanomaterials have recently gained a great interest due to the variety of applications that can have in the field of biomedicine. This work covers both diagnostic and therapeutic possibilities that present two types of nanomaterials: iron oxide nanoparticles and gold nanoparticles. Therefore, in a first approximation it has performed the characterizing of nanoparticles from the standpoint of biocompatibility associated with their size and time of contact or movement in cells and tissues, tested both in vitro and in vivo as well as the kinetics of accumulation of the nanoparticles into the living organism. Subsequently the biofunctionalization of two types of nanoparticles was made to recognize specific molecular targets and can be used in the future in two different biomedical applications: diagnosis of Alzheimer's disease by magnetic resonance imaging and selective destruction of tumor cells by optical hyperthermia.