Treatment with gold nanoparticles (Au NPs) exhibit a variety of biological effects, including anti-inflammatory effects. In the present study, we investigated the effect of intranasal treatment with the Au NPs on allergic inflammatory response induced by ovalbumin (OVA) in rats subjected to experimental model of asthma. The animals were sensitized on days 0, 7 and 14 by intraperitoneal injection with 50 mg OVA. On days 21, 22 and 23 after the initial stimulus, the animals were challenged with OVA (50 mg / 25 μl PBS) intranasally. Treatment with the Au NPs (6 or 60 mg / kg) occurred 1 h before the antigen challenge, and the evaluation of the biological parameters performed 48 h after the last challenge. The effect of Au NPs in airway hyperresponsiveness induced by methacholine was investigated by determining the resistance and elastance; eosinophil infiltration, peribronchial fibrosis and mucus production were investigated using histological techniques; Leukocyte infiltration and production of pro-inflammatory mediators in allergic airways induced stimulation by enzyme- linked immunoassay (ELISA); The production of reactive oxygen species in vitro and in vivo measures was the reduction of nitroblue tetrazolium (NBT) and flow cytometry using cells labeled with 2 ', 7'-dichlorofluorescein diacetate (DCFH-DA), respectively; The interference ability of Au NPs on phagocytosis, generation of TNF-α in murine macrophages and viability was evaluated by determining the phagocytic capacity, ELISA and MTT method, respectively. In the lungs, treatment with Au NPs reduced eosinophil infiltration after OVA challenge by attenuated production of mucus reversed resistance and increased lung compliance and decreased levels of IL-4, IL-13, KC, eotaxin-1 and eotaxin-2 in the lung tissue. Additionally, in vitro, macrophages exposed Au NPs in non-cytotoxic doses, when activated with zymosan showed a decrease in the production of reactive oxygen species (ROS) and secretion of TNF-α. Taken together, our results demonstrate the anti-inflammatory properties of the Au NPs and its association with reduced leukocyte infiltration, suppression of production of proinflammatory cytokines and antioxidant effect. The Au NPs were found to be a therapeutic option for the treatment of allergic inflammation. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O tratamento com nanopartículas de ouro (NPs Au) exibem uma variedade de efeitos biológicos, incluindo efeitos anti-inflamatórios. No presente estudo, investigamos o efeito do tratamento intranasal com as NPs Au sobre a resposta inflamatória alérgica induzida por ovalbumina (OVA) em camundongos submetidos ao modelo experimental de asma. Os animais foram sensibilizados nos dia 0, 7 e 14 por via intraperitoneal com 50 µg de OVA. Nos dias 21, 22 e 23 após o estímulo inicial, os animais foram desafiados com OVA (50 μg/25 μl PBS) por via intranasal. O tratamento com as NPs Au (6 ou 60 μg/Kg) ocorreu 1 hora antes do desafio antigênico, sendo a avaliação dos parâmetros biológicos realizada 48 h após o último desafio. O efeito das NPs Au na hiperresponsividade brônquica induzida por metacolina foi investigada por meio da determinação da resistência e elastância; o infiltrado eosinofílico, fibrose peribrônquica e produção de muco foram investigadas através de técnicas histológicas; O infiltrado leucocitário e a produção de mediadores pró-inflamatórios nas vias áreas induzidos por estímulo alérgico pelo método de ensaio imunoenzimático (ELISA); A produção de espécies reativas de oxigênio in vitro e in vivo foi mensura pela redução do nitroblue tetrazolium (NBT) e citometria de fluxo utilizando células marcadas com 2',7'- diacetato de diclorofluoresceína (DCFH-DA), repectivamente; A capacidade de interferência das NPs Au sobre a fagocitose, geração de TNF-α e viabilidade em macrófagos murinos foi verificado pela determinação da capacidade fagocítica, ELISA e método de MTT, respectivamente. No pulmão, o tratamento com as NPs Au reduziu o infiltrado eosinofílico após desafio por OVA, atenuou a produção de muco, reverteu o aumento da resistência e elastância pulmonar e reduziu os níveis de IL-4, IL-13, KC, eotaxina-1 e eotaxina-2 no tecido pulmonar. Adicionalmente, in vitro, macrófagos expostos as NPs Au em doses não citotóxicas, quando ativados com zimosan apresentaram uma diminuição na produção de espécies reativas oxigenadas (ERO) e a secreção de TNF-α. Em conjunto, nossos resultados demostraram as propriedades anti-inflamatórias da NPs Au e sua associação com a redução do infiltrado leucocitário, supressão na produção de citocinas pró-inflamatórias e efeito antioxidante. As NPs Au revelaram-se como uma opção terapêutica para o tratamento da inflamação alérgica.

ABSTRACT SENSITIVE AND QUANTITATIVE DETERMINATION OF CYSTEINE BY SURFACE ENHANCED RAMAN SPECTROMETRY BASED ON THEIR INDUCED AGGREGATES OF GOLD AND SILVER NANOSTRUCTURES Y&uuml / ksel, Recep M.Sc., Department of Chemistry Supervisor: Prof. Dr. M&uuml / rvet Volkan September 2011, 76 pages The synthesis of noble metal nanostructures are an active research area and controlling the shape and the size is a challenging task. In this study, nanostructures with different morphologies were prepared using wet chemical synthesis techniques in the aqueous solutions. Gold and silver nanospheres were produced by reducing and capping agent trisodium citrate. Gold nanorods were synthesized by chemical reduction of HAuCl4 by ascorbic acid in the presence of cetyltrimethylammonium bromide (CTAB), AgNO3, and gold nanoseeds (in 1.5 nm diameter) and gold silver core shell nanorods were prepared by addition of silver atoms on the surface of gold nanorods in the presence of CTAB. Parameters that were critical to obtain homogeneous nanostructures were optimized. The characterization of the nanoparticles was performed by UV-VIS spectrometry, High Resolution - Transition Electron Microscopy (HR-TEM), Field Emission - Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-ray Spectroscopy (EDX). Besides, their electromagnetic enhancement properties were demonstrated through SERS measurement of cysteine. Self-assembly or assisted assembly of nanorods or nanospheres into organized arrays allows the realization of their collective properties that arise from the coupling of the optical and electronic properties of the neighbouring individual nanoparticles. In this study cysteine molecule was used as a linker molecule. The controlled addition of cysteine into the gold nanorod solution resulted in their preferential binding to the two ends of the gold nanorods and the formation of gold nanochains. In the usage of gold nanospheres on the other hand, cooperative hydrogen bonding of the cysteine molecules, resulted in the formation of gold nanoclusters. The assembly formation was demonstrated by UV&ndash / vis spectrometry and FE-SEM. Cysteine is a thiol group containing amino acid and deficiency of cysteine results in serious health problems. Therefore, determination of cysteine is an important issue. Herein we report two strategies for the quantitative determination of micromolar concentrations of cysteine by exploiting the interplasmon coupling in Au nanoparticles. One of them is a recently published colorimetric method and the other is a novel SERS method.