Two designs of inorganic/organic hybrid micro-structures are discussed: (1) silver nanowire reinforced layer-by-layer (LbL) polyelectrolyte composite film and (2) bimetallic silver-gold core-shell nanoparticles. In this work, zero-dimensional spherical gold nanoparticles (AuNPs), one-dimensional silver nanowires (AgNWs), and two-dimensional silver nanoplates (AgNPls) represent the inorganic component. Three-arm star polymer and polyelectrolytes represent the organic component. In the first design, the one-dimensional AgNWs serves as a mechanical reinforcement for the fabrication of mechanically isotropic and anisotropic polyelectrolyte composite films. The composite film is mechanically isotropic when the AgNWs are randomly oriented, and it is anisotropic when the AgNWs are unidirectionally oriented within the LbL polyelectrolyte matrix. Furthermore, above the AgNWs percolation threshold, the AgNWs reinforced LbL composite film is electrically conductive. Therefore, it can find application in ultrathin LbL film-based sensor. In the second design, the zero-dmensional AuNPs were assembled onto one-dimensional AgNWs and two-dimensional AgNPls by means of star polymer linker, or alternatively using polyelectrolytes via electrostatics interaction. The unique feature of these bimetallic silver-gold core-shell nanoparticles is their ability to greatly enhance electric field, due to the silver-gold intra-particle interaction. This allows it to serve as a single-nanoparticle surface enhanced Raman scattering (SERS) substrate for chemical sensing.

La diffusion Raman exaltée de surface (SERS) est utilisée pour la mise au point d’un biocapteur capable de détecter des pesticides dans l’eau, en se basant sur le suivi de l’activité enzymatique de l’Acétylcholinestérase (ACHE). Les nanoparticules d’or sont utilisées comme substrats SERS actifs. Le signal Raman exalté de l’analyte est optimisé en testant plusieurs types de nanoparticules.Le Raman SERS a permis la détection directe du Paraoxon (PO) et du carbaryl (CA) et la possibilité de suivi de l’activité de l’ACHE. En absence d'inhibiteurs, la molécule d’acétylcholine (ATC) est transformée en acide acétique et en choline par l’enzyme ACHE. La mesure de l’activité de l’ACHE repose sur le suivi des concentrations en ATC car sa transformation est inhibée en présence de pesticides. Il a été ainsi possible d’établir une relation linéaire entre la concentration de pesticides et l’exaltation du signal Raman de l’ATC non transformé. La méthode a permis la détection du PO et du CA, avec une limite de détection beaucoup plus faible que la détection directe. Ce biocapteur basé sur l’activité de l’ACHE a ensuite été utilisé pour l'évaluation d’autres polluants (inhibiteurs d’ACHE) comme les additifs contenus dans les plastiques notamment. Enfin, nous avons développé une seconde approche qui consistait à mesurer l’activité de l’ACHE en utilisant la diffusion dynamique de la lumière. En effet, nous avons montré que les paramètres physicochimiques (agrégation) des AuNPs en contact avec certaines molécules, sont fortement influencés par l’activité enzymatique de l’ACHE. C’est ce phénomène d’instabilité qui nous a permis de distinguer entre les deux cas : absence et présence de PO. / Surface-enhanced Raman scattering (SERS) was used to develop a biosensor for the detection of pesticides through the monitoring of the enzymatic activity of acetylcholinesterase (ACHE). Gold nanoparticles (AuNPs) were used as an active SERS substrate. The enhanced Raman signal of the analyte is optimized by testing several types of nanoparticles. Raman SERS allowed the direct detection of Paraoxon (PO) and carbaryl (CA) pesticides and the possibility of follow-up of the activity of the ACHE. In the absence of inhibitors, the acetylcholine (ATC) is transformed into acetic acid and choline by the enzyme ACHE. The measurement of ACHE activity is performed through the monitoring of ATC concentrations because its transformation is inhibited in the presence of pesticides. Results showed a linear correlation between the concentration of pesticides and the SERS signal of the untransformed ATC. The method was optimized for the quantification of paraoxon and carbaryl with a limit of quantification much lower than the one obtained with a direct detection. Their identification was also possible using chemometrics. This biosensors, based on the ACHE activities, was applied to the evaluation of emergent pollutants: additives of commercial polymers. Our results suggested that most of the tested polymers contained molecules that act as inhibitors of the ACHE. Finally, we propose another very simple approach to measure the ACHE activity using dynamic light scattering measurements. We found that the physicochemical parameters (aggregation) of AuNPs were strongly influenced by the enzymatic activity of ACHE when in contact with specified molecules, allowing to detect the presence of PO.

Cellular therapy is emerging as a clinically viable strategy in the field of solid organ transplantation, where it is expected to reduce the dependency on conventional immunosuppression. This has produced a demand for highly sensitive methods to monitor the persistence and tissue distribution of administered cells in vivo. However, tracking cells presents significant challenges. In many cases transplanted cells are autologous with the immune system of the transplant recipient, and hence are invisible to typical methods of detection. To enable their differentiation, the cells must be labelled with a suitable, non-toxic and long lifetime label, prior to their administration to patients. In addition, administered cells represent only a small fraction of the recipient's endogenous cells, which necessitates the use of an extremely sensitive detection method. Laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS) is an exquisitely sensitive analytical technique, capable of imaging trace elements in complex samples, at high spatial resolution.

[pt] Norfloxacina (NFX) é um antibiótico fluorescente de amplo espectro bacteriológico, membro da família das fluorquinolonas (FQs). A interação das FQs com íons metálicos pode incrementar a ação bactericida e agir contra a resistência das bactérias frente aos antibióticos. Diversos exemplos de complexos mistos de norfloxacina e Cu(II) podem ser encontrados na literatura. A compreensão dos mecanismos moleculares de interação desses antibióticos com os diferentes componentes das células e com nanopartículas de ouro, como transportadores do fármaco, é extremamente importante. Para entender essas interações, neste trabalho utilizamos diferentes técnicas espectroscópicas, como espectroscopia de fluorescência estacionária e resolvida no tempo, absorção de luz UV-Visível e ressonância paramagnética eletrônica (RPE). A interação de NFX e do complexo ternário Cu(II):L:NFX, onde o ligante L é a 1,10-fenantrolina (Phen) ou 2,2-bipiridina (Bipy), com micelas e lipossomas unilamelares pequenos de fosfatidilcolina de ovo (PC) foi estudada usando espectroscopia de fluorescência em estado estacionário e resolvida no tempo. Foi estudada a estabilidade dos complexos ternários formados em micelas. Foram obtidas constantes de estabilidade no interior de micelas de SDS, as quais mostraram valores muito maiores do que em tampão. Já os espectros de RPE deram maiores detalhes sobre a estrutura dos complexos e confirmaram a formação do complexo ternário dentro das micelas. Foram estudadas as interações de FQs e seus complexos de cobre com lipossomas de PC preparados com diferentes densidades superficiais de carga elétrica negativa. No estudo da interação de FQs com nanopartículas de ouro sintetizadas por ablação a laser (nanocompósitos, AuNCs), NFX mostrou maiores mudanças, tanto na absorbância como na fluorescência, do que as FQs ciprofloxacina (CFX) e levofloxacina (LFX). Os resultados sugerem mudanças no índice de refração na superfície dos AuNCs, por associação com o fármaco e/ou formação de aglomerados como resultado da interação. Observou-se também uma supressão lenta, porém significativa, na fluorescência da NFX, sem mudança na posição do pico, indicando que NFX mantém o seu estado inicial de protonação ligando-se à superfície dos AuNCs. Também foi observada a liberação de FQs ligadas à superfície de AuNPs mediante substituição por tióis, que ocasiona recuperação parcial da fluorescência da fluorquinolona. Por último, como o surfactante aniônico SDS se mostrou promissor na interação com NFX, em comparação com surfactantes catiônicos e neutros, e como os AuNCs são estáveis em SDS, estudamos a interação de NFX com AuNCs sintetizados em presença de SDS e, para comparação, com AuNCs colocados em solução de SDS após a síntese. / [en] Norfloxacin (NFX) is a fluorescent antibiotic of broad bacteriological spectrum, member of the fluoroquinolone (FQ) family. The interaction of FQs with metal ions can increase the bactericidal action and act against antibiotics bacterial resistance. Several examples of mixed-ligand norfloxacin Cu (II) complexes can be found in the literature. Understanding the molecular mechanisms of interaction of these antibiotics with different cell components and with gold nanoparticles as drug transporters is extremely important. To clarify these interactions, we used different spectroscopic techniques, such as steady-state and time-resolved fluorescence spectroscopy, UV-Visible light absorption, and electron paramagnetic resonance (EPR). The interaction of NFX and the ternary complex Cu(II):L:NFX, where the L is the ligand 1,10-phenanthroline (Phen) or 2,2-bipyridine (Bipy), with micelles and small unilamellar liposomes of egg phosphatidylcholine (PC) was studied using steady-state and time-resolved fluorescence spectroscopy. The stability of the ternary complexes formed in micelles was studied, and stability constants were obtained inside SDS micelles, which showed values much larger than in buffer. The EPR spectra gave further details on the structure of the complexes, and confirmed the formation of the ternary complex inside the micelles. The interactions of FQs and their copper complexes with PC liposomes prepared with different surface densities of negative electrical charge were studied. In the study of the interaction of FQs with gold nanoparticles synthesized by laser ablation (nanocomposites, AuNCs), NFX showed greater changes than FQs ciprofloxacin (CFX) and levofloxacin (LFX) in both absorbance and fluorescence. The results suggest changes in the surface refractive index of the AuNCs and/or cluster formation, as result of the interaction with the drug. A slow but significant quenching of NFX fluorescence was also observed, with no change in peak position, indicating that NFX maintains its initial state of protonation by binding to the surface of the AuNCs. Release of FQs attached to the surface of AuNCs by thiols has also been observed, which causes partial recovery of FQ fluorescence. Finally, as the anionic surfactant SDS showed to be promising in the interaction with NFX, compared to cationic and neutral surfactants, and because the AuNCs are stable in SDS, we studied the interaction of NFX with AuNCs synthesized in the presence of SDS and, for comparison, with AuNCs placed in SDS solution after synthesis.

Magister Scientiae - MSc / Coeliac disease (CD) is a gluten intolerance condition that results in the flattening of the villi, which line the bowel. It is the most common cause of malabsorption of food nutrients. This inability to absorb sufficient levels of nutrients causes many of the common symptoms experienced by CD patients. Some of the symptoms, which lead to an increase in mortality rate, include chronic diarrhea, fatigue, iron-deficient anemia and osteoporosis. People with CD have higher than normal levels of certain antibodies in their blood. Thus, the concentration of anti-transglutaminase antibody (anti-tTG) in human sera is an important analytical marker for the diagnosis of CD. An immunosensor is a type of biosensor that has an antigen or antibody fragment as its biological recognition component. The specificity of the molecular recognition of antigens by antibodies to form a stable complex is the basis of immunosensor technology. In this work, overoxidized polypyrrole (OvoxPpy) was electrosynthesized as a noval sensor platform on a glassy carbon electrode (GCE). The OvoxPpy was then doped with gold-nanoparticles (GNP) by electrodeposition using cyclic voltammetry to form GNP|OvoxPpy||GCE electrode system. Morphology and size of the GNP|OvoxPpy||GCE nanocomposite were determined using scanning electron microscopy. The electrochemical immunosensor for anti-tTG antibodies was prepared by immobilizing transglutaminase antigen (tTG-antigen) onto the GNP|OvoxPpy||GCE by drop coating and allowed to incubate for 2 hrs. The electrochemical characterization of the nanocomposite platform and immunosensor were studied by voltammetry and electrochemical impedance spectroscopy (EIS). Charge transfer resistance, Rct (obtained from EIS data fitting) of [Fe (CN)6]3-/4- redox probe was used as the analytical parameter for measuring the interfacial kinetics which occurred as a result of the bio-recognition event (affinitive binding) between the tTG-antigen and anti-tTG antibody. Rct was found to increase with increased concentration of the antibody as a result of the reluctance to the flow of redox probe charge across the interface. Antibody concentration as low as in 1:4000 dilutions was detected. / South Africa

Philosophiae Doctor - PhD / In the presented work, immunosensors for detection of Aflatoxin B1 based on different immobilization platforms were studied. Synthesis of an electroactive hydrogel was also carried out. Aflatoxins are a group of mycotoxins that have deleterious effects on humans and are produced during fungal infection of plants or plant products. Electrochemical immunosensor for the determination of Aflatoxin B1 (AFB1) was developed with anti-aflatoxin B1 antibody immobilized on Pt electrodes modified with polyaniline (PANi) and polystyrene sulphonic acid (PSSA). Impedimetric analysis shows that the electron transfer resistances of Pt/PANi-PSSA electrode, Pt/PANi-PSSA/AFB1-Ab immunosensor and Pt/PANi-PSSA/AFB1-Ab incubated in BSA were 0.458, 720 and 1066 kΩ, respectively. These results indicate that electrochemical impedance spectroscopy (EIS) is a suitable method for monitoring the change in electron-transfer resistance associated with the immobilization of the antibody. Modelling of EIS data gave equivalent circuits which showed that the electron transfer resistance increased from 0.458 kΩ for Pt/PANi-PSSA electrode to 1066 kΩ for Pt/PANi-PSSA/AFB1-Ab immunosensor, indicating that immobilization of the antibody and incubation in BSA introduced an electron transfer barrier. The AFB1 immunosensor had a detection limit of 0.1 mg/L and a sensitivity of 869.6 kΩL/mg. / South Africa

Philosophiae Doctor - PhD / In the presented work, immunosensors for detection of Aflatoxin B1 based on different immobilization platforms were studied. Synthesis of an electroactive hydrogel was also carried out. Aflatoxins are a group of mycotoxins that have deleterious effects on humans and are produced during fungal infection of plants or plant products. Electrochemical immunosensor for the determination of Aflatoxin B1 (AFB1) was developed with anti-aflatoxin B1 antibody immobilized on Pt electrodes modified with polyaniline (PANi) and polystyrene sulphonic acid (PSSA). Impedimetric analysis shows that the electron transfer resistances of Pt/PANi-PSSA electrode, Pt/PANi-PSSA/AFB1-Ab immunosensor and Pt/PANi- PSSA/AFB1-Ab incubated in BSA were 0.458, 720 and 1066 kΩ, respectively. These results indicate that electrochemical impedance spectroscopy (EIS) is a suitable method for monitoring the change in electron-transfer resistance associated with the immobilization of the antibody. Modelling of EIS data gave equivalent circuits which showed that the electron transfer resistance increased from 0.458 kΩ for Pt/PANi-PSSA electrode to 1066 kΩ for Pt/PANi- PSSA/AFB1-Ab immunosensor, indicating that immobilization of the antibody and incubation in BSA introduced an electron transfer barrier. The AFB1 immunosensor had a detection limit of 0.1 mg/L and a sensitivity of 869.6 k ΩL/mg. In the second platform an immunosensor based on gold nanoparticles (AuNP) and polythionine-modified glassy carbon electrode (GCE) for the determination of aflatoxin B1 (AFB1) was developed. Aflatoxin B1-BSA conjugate was immobilised on the modified GCE. Horseradish peroxidase (HRP) or Bovine serum albumin (BSA) were used to block sites against non-specific binding of the AFB1- conjugate with other compounds such as the salts used in preparing the buffer when the antibody interacts with the AFB1 conjugate and free AFB1. Competition reaction was allowed to take place between the free AFB1 and AFB1-conjugate for the binding sites of the anti-aflatoxin B1 antibody. Cyclic voltammetry (CV) was employed to characterize the electrochemical properties of the modified process. The peak separation of the immunosensor (ΔEp) was 62 mV indicating a quasi reversible process. Differential pulse voltammetry (DPV) was used to monitor the analytical signal. The response decreased with an increase in AFB1 concentration in the range of 0.6-2.4 ng/mL with a limit of detection of 0.07 and 0.16 ng/mL for HRP and BSA blocked immunosensors respectively. Significantly the low detection limit of 0.07 ng/mL is within the limits set by worl health organization (WHO) for AFB1 and its derivatives which is 2 ng/mL The proposed method eliminates the use of secondary antibody enzymatic labels. Synthesis and characterization of (p-(HEMA)-polyaniline hydrogels were investigated. The hydrogels were synthesized using: 2-Hydroxyeththyl methacrylate (HEMA), N-Tris (hydroxymethyl) methyl] acrylamide, 3- Sulfopropyl methacrylate potassium salt, Tetraethylene glycol diacrylate, Poly-(2- hydroxyethyl methacrylate), 2, 2-Dimethoxy-2-phenylacetophenone and aniline by UV irradiation. Two sets of the hydrogels were prepared using water / 1, 3, 3, 3-(tetramethyl butyl phenyl polyethylene glycol [Triton X-100] and water / ethylene glycol as the solvent. Scanning electron microscopy (SEM) revealed a more uniform pore size when Triton X 100 (TX-100 HG) was used as compared to ethylene glycol (EG-HG). Thermogravimetric analysis (TGA) showed that both hydrogels were stable up to 270 oC. Fourier transform-Infra red (FTIR) spectrum confirmed the incorporation of polyaniline (PANi) and HEMA in the composite. Electrochemical properties of the hydrogels evaluated using Cyclic Voltammetry and Electrochemical Impedance Spectroscopy (EIS) demonstrated the electroactivity and conductivity.

In recent years, the interest in improving the properties of liquid-crystalline systems by using metallic nanoparticles has grown. This is because these materials have particular optical and electrical characteristics, associated with the plasmon resonance phenomenon. Recently, several studies have shown that the addition of gold nanoparticles affects the electrical response of liquid crystals depending on the nanoparticles geometry and the liquid-crystalline alignment. In this study, we investigated the effects of the addition of gold nanoparticles with different geometries on the relaxation time of the 4-octyl-4-cyanobiphenyl (8CB) liquid crystal, under the helical confinement conditions. We used an experimental setup that explores the Brewster angle to investigate how the application of a external electrical field and temperature of the system affect the reorientation dynamics of the director vector nearby the transition of nematic-smectic-A phase. The results obtained were analyzed within the elastic theory of Franck-Oseen e allowed us to evaluate the effects of nanoparticles on the viscoelastic parameters of the system. Our results show that the addition of nanoparticles significantly affects the electro-optical response of the investigated liquid crystals, especially in conditions of high temperature and low amplitude of the applied electrical field. In addition, we have observed that the geometry of the nanoparticles plays a key role in the modification of the electro-optical properties of the system. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nos últimos anos, tem crescido o interesse no melhoramento das propriedades de sistemas líquido-cristalinos usando nanopartículas metálicas. Isso porque esses materiais apresentam propriedades ópticas e elétricas particulares, associadas ao fenômeno de ressonância de plásmon. Recentemente, vários trabalhos têm demonstrado que a adição de nanopartículas de ouro afetam a resposta elétrica de cristais líquidos dependendo da geometria das nanopartículas utilizadas e do alinhamento líquido-cristalino. Neste trabalho, nós investigamos os efeitos da adição de nanopartículas de ouro com diferentes geometrias sobre o tempo de relaxação de amostras do cristal liquido 4-octil-4-cianobifenil (8CB) nas condições de confinamento helicoidal. Nós usamos um aparato experimental que explora o ângulo de Brewster para investigar como a aplicação de um campo elétrico externo e a temperatura do sistema afetam a dinâmica de reorientação do vetor diretor nas proximidades da transição de fase nemática-esmética-A. Os resultados obtidos foram analisados dentro da teoria elástica de Franck-Oseen e permitiu-nos avaliar os efeitos das nanopartículas sobre os parâmetros viscoelásticos do sistema. Nossos resultados mostram que a adição de nanopartículas afeta significativamente a resposta elétro-óptica dos cristais líquidos investigados, especialmente nas condições de alta temperatura e baixa amplitude do campo elétrico aplicado. Além disso, nós observamos que a geometria das nanopartículas desempenha um papel fundamental namodificação das propriedades eletro-ópticas do sistema.

La détection de petites molécules est d'un grand intérêt dans les domaines pharmaceutique, environnemental, alimentaire et de la biologie clinique. Les aptamères, sélectionnés par la méthode SELEX (pour Systematic Evolution of Ligands by Exponential Enrichment), sont des oligonucléotides qui se lient à une cible donnée avec une affinité et une spécificité importantes. L'objectif de ce travail est d'établir de nouvelles méthodologies analytiques basées sur l'utilisation des aptamères pour la détection de petites molécules. Dans un premier temps, une méthodologie par électrophorèse capillaire, dérivée du concept de déplacement du brin complémentaire de l'aptamère, est décrite pour la détection simultanée de plusieurs analytes dans un seul capillaire. La deuxième étude se focalise sur le développement d'un aptacapteur colorimétrique simple, rapide et peu coûteux, qui utilise le concept général de protection enzymatique de l'aptamère et les nanoparticules d'or en tant que système de transduction. Enfin, deux méthodes par polarisation de fluorescence, basées sur le concept de déplacement (du brin complémentaire ou de l'aptamère lui-même), sont présentées afin d'accroitre les potentialités des aptacapteurs dédiés à la détection des petites molécules. / Small biomolecule detection is of great interest and importance in the pharmaceutical, environmental, food and clinical fields. Aptamers, selected by SELEX (Systematic Evolution of Ligands by Exponential Enrichment), are oligonucleotides that bind to a target with high affinity and specificity. The objective of the work is to establish novel methodologies of aptamer-based assays for the small biomolecule detection. In the first work, a rationalized capillary electrophoresis strategy, derived from the structure-switching aptamer concept, is described for the design of simultaneous detection of multiple analytes. The second work based on a gold nanoparticle colorimetric sensing strategy allows a rapid, label-free, homogeneous assay for small molecule using an aptamer enzymatic cleavage protection strategy. In the third work, two aptamer-based fluorescence polarization approaches, using the displacement concept, are described to improve the potentialities of the small molecule-dedicated aptasensors.

Made available in DSpace on 2016-06-02T19:22:59Z (GMT). No. of bitstreams: 1 5493.pdf: 2266591 bytes, checksum: fcc52b05d86dfd96d2e89c3f4e1f85dd (MD5) Previous issue date: 2013-07-05 / Financiadora de Estudos e Projetos / The process of formation and remodeling of bone tissue is influenced by several factors such as hormones, nutrition, genetics, sex, age, intercurrent disease and environmental factors. There are published reports of the performance of nanoparticles on the development and bone remodeling, and also on kidney, liver and heart. The objective of this study was to analyze the possible influence of gold nanoparticle (AuNPs) exposure on bone tissue and on kidney, heart and liver. After a single intravenous AuNPs exposure biometric, biophysical and biomechanical bone parameters of adult rats were analyzed. The animals were randomly distributed into three groups (1 week, 1 month and 2 months), divided into four, which were respectively treated with polymer poliaminoamida (PAMAM), PAMAM + AuNPs, citrate (citrate buffer) and citrate + AuNPs. Gold nanoparticles were administered by a single dose (0,01 mg Au/kg MC),via the jugular vein. The biomechanical properties of femurs were obtained by the three point bending test. The mass of the kidney, liver and heart were also analyzed. There were no significant differences of the different bone parameters and organs weights among the groups in their respective treatment periods. Therefore, the results indicated that the dose of AuNPs used in this study did not impair the quality of bone tissue as well as the organ weights. These results may help in understanding the possible actions of AuNPs on the bone tissue and organs. / O processo de formação e remodelamento do tecido ósseo é influenciado por diversos fatores tais como hormonais, alimentação, genética, sexo, idade, doenças intercorrentes e fatores ambientais. Há relatos na literatura da atuação de nanopartículas sobre o desenvolvimento e remodelamento ósseo e de sua influência sobre rim, fígado e coração. O objetivo deste estudo foi analisar possíveis influências da exposição de nanopartículas de ouro (AuNPs ) sobre o tecido ósseo, rim, fígado e coração. Após uma única exposição intravenosa, foram analisados parâmetros biométricos, biofísicos e biomecânicos ósseos de ratos adultos e o peso úmido do rim, coração e fígado. Os animais foram distribuídos aleatoriamente em três grupos (uma semana, um mês e dois meses), subdivididos em quatro, os quais foram tratados respectivamente com polímero poliaminoamida (PAMAM), PAMAM + AuNPs, Citrato (tampão citrato) e Citrato + AuNPs. As nanopartículas de ouro foram administradas em dose única (0,01 mg Au/kg MC), via veia jugular. As propriedades biomecânicas dos fêmures foram obtidas pelo teste de flexão a três. Não houve diferenças significativas dos diferentes parâmetros ósseos e massa dos órgãos entre os grupos nos seus respectivos períodos de tratamento. Portanto, os resultados apontam que a dose de AuNPs utilizada neste estudo não prejudicou a qualidade do tecido ósseo assim como a massa dos órgãos. Estes resultados podem auxiliar no entendimento de possíveis ações de AuNPs sobre o tecido ósseo e dos órgãos.