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The antimicrobial effects of silver nanoparticles were studied. Silver nanoparticles were synthesized through wet chemistry method, and were dispersed in aqueous suspension. With nanoscale silica particles served as heterogeneous nucleation sites, silver nanoparticles were formed anchoring on the silica surface. Suspensions were found to be stable at high silver concentrations as well as over a broad pH range. By varying the processing conditions, diameter of the silver nanoparticles could be controlled between ~2 nm to ~25 nm. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to reveal the formation and the corresponding morphology of the silver-silica coupling nanoparticles. Ultra-violet visible (UV-vis) scanning spectrophotometer was used to detecting the distinct absorption spectrum of silver nanoparticles. The antimicrobial activities of these silver-silica coupling nanoparticles were investigated. E. coli and S aureus were used as representatives of Gram-negative and Gram-positive bacteria, respectively. Bacteriological tests showed either bacterial growth inhibition or cell death occurred, corresponding to different concentrations of silver nanoparticles and the type of bacteria that were testing on. Fluorescent microscopic images were also provided to confirm the bacterial viability after several hours' treatment with silver nanoparticles. / Master of Science

The objective of this research was the development of an efficient method for the preparation of silver-polymer nanocomposites containing finely dispersed silver nanoparticles. The surface of nanosilver was functionalized by thiolation with 2-aminoethanethiol. Amino-modified nanosilver was covalently bonded to polyacrylic acid, biodegradable polymers like acid terminated polylactic acid, ester terminated poly(DL-lactide-co-glycolide) and acid terminated poly(DL lactide-co-glycolide) in the presence of diisopropylcarbodiimide by carbodiimide method. Esterification of the carboxyl groups of Ag-polyacrylic acid by hydrochloric acid in methanol resulted in the formation of a stable colloidal dispersion of Ag nanoparticles in the polymer matrix. It was observed that not just acid terminated polymers but also ester terminated polymers could react with functionalized nanosilver. This unusual reaction was due to the aminolysis of the ester bond in the polymer chain by the surface amino groups. Silver-polymer nanocomposites obtained with acid terminated polylactic acid and poly(DL-lactide-co-glycolide) contained highly dispersed nanosilver in the polymer matrix in comparison with the ester terminated poly(DL-lactide-co-glycolide). Chemical and structural characteristics of the obtained materials were studied by instrumental methods. Attained biodegradable materials confirmed X-ray contrast and bactericidal properties, which could be eventually used for biomedical applications.

The objective of this research was the development of a novel synthetic method for preparation of silver/polymer nanocomposites containing finely dispersed silver nanoparticles. The surface of nanosilver was functionalized by amino groups, which then reacted with end acidic groups of polylactide (PLA) and its co-polymer with polyglycolide (PLGA). The condensation reaction was conducted in the presence of diisopropylcarbodiimide. Nanosilver coating with the polymers was confirmed by FT-IR and UV-vis spectroscopy. It was found that not only acid-terminated but also ester-terminated polymers can react with functionalized nanosilver. However, high dispersibility of the nanoparticles was achieved with acid-terminated polymers only. Obtained materials demonstrated X-ray contrast and bactericidal properties that makes possible their prospective application in biology and medicine.

Objetivo: Evaluar el límite de inhibición bacteriana del Hidróxido de Calcio en polvo sobre cepas de Enterococcus faecalis ATCC® 29212™. Materiales y Métodos: Este estudio experimental in vitro utilizó 40 placas petri con agar BHI solidificado. Se preparó la solución de Hidróxido de Calcio [Ca(OH)2] en polvo de la marca Biodinámica y Maquira a la concentración de 1g/ml. La Concentración Mínima Inhibitoria (CMI) y la Concentración Mínima Bacteriostática (CMB) fueron evaluadas mediante diferentes concentraciones de Ca(OH)2 (0.02 g/ml - 1g/ml). La CMI fue evaluada mediante la técnica de Kirby Bauer y la CMB mediante la técnica de Recuento de Unidades Formadoras de Colonia (UFC). Resultados: Al evaluar la actividad antibacteriana de Ca(OH)2 contra la cepa de E. faecalis, se observó las siguientes medias del halo de inhibición: Biodinámica 22.66 ± 0.38 mm; Maquira 23.58 ± 0.47 mm y Clorhexidina al 12% (control positivo) 23.93 ± 0.73 mm. La CMI del Ca(OH)2 en polvo de ambas marcas fue de 0.063 g/ml como límite inferior, confirmando la inhibición del crecimiento de la cepa de Enterococcus faecalis ATCC® 29212™, siendo el límite superior de 1g/ml. Por otro lado, el CMB del Ca(OH)2 en polvo muestra un valor de 0.031 g/ml para la marca Biodinámica y 0.063 g/ml. para la marca Maquira. Conclusión: El límite inferior y superior de inhibición bacteriana del Hidróxido de Calcio, sobre cepas de Enterococcus faecalis ATCC® 29212™ fue de 0.063 g/ml y de 1gr/ml, respectivamente. / Objective: To evaluate the bacterial inhibition limit of Calcium Hydroxide powder on strains of Enterococcus faecalis ATCC® 29212™. Materials and Methods: This in vitro experimental study used 40 petri dishes with solidified BHI agar. The solution of Calcium Hydroxide [Ca(OH)2] powder of the brand Biodinámica and Maquira was prepared at the concentration of 1 g / ml. The Minimum Inhibitory Concentration (MIC) and the Minimum Bacteriostatic Concentration (MBC) were evaluated using different concentrations of Ca(OH)2 (0.02 g /ml - 1 g/ml). The CMI was evaluated using the Kirby Bauer technique and the CMB using the Colonies Formation Units (CFU) technique. Results: The antibacterial activity of Ca(OH)2 against the E. faecalis strain, presented the following means of inhibition halo were observed: Biodinámica 22.66 ± 0.38 mm; Maquira 23.58 ± 0.47 mm and 12% Chlorhexidine (positive control) 23.93 ± 0.73 mm. The MIC of the Ca(OH)2 powder of both brands was 0.063 g / ml as the lower limit, confirming the inhibition of the growth of Enterococcus faecalis ATCC ® 29212 ™ strain with the upper limit of 1 g / ml. On the other hand, CMB of the Ca(OH)2 powder shows a value of 0.031 g / ml for Biodinámica and 0.063 g / ml. for Maquira. Conclusion: The lower and upper limit of bacterial inhibition of Calcium Hydroxide, on strains of Enterococcus faecalis ATCC ® 29212™ was 0.063 g / ml and 1 g / ml, respectively. / Tesis

As L-aminoácido oxidases (LAAOs) isoladas de peçonhas de serpentes são alvos de um grande número de pesquisas devido às suas inúmeras ações biológicas e farmacológicas. O objetivo do presente trabalho foi caracterizar funcionalmente a Laminoácido oxidase da peçonha de Calloselasma rhodostoma (CR-LAAO) por meio das atividades: bactericida, fungicida, leishmanicida, tripanomicida, citotóxica, inflamatória e análise da expressão de genes e proteínas apoptóticas. A CR-LAAO mostrou-se altamente citotóxica sobre as células tumorais HepG2 e HL-60, promovendo cerca de 80% de morte celular na maior concentração testada (100 ?g/mL) e apresentou baixa toxicidade sobre células PBMC. Foi possível observar que a proteína induziu apoptose (AV+) em PBMC. Em HepG2, as menores concentrações (0,1-2,5 ?g/mL) causaram apoptose (AV+), e as maiores (5-100 ?g/mL) causaram apoptose/necrose (PI+/AV+). Em HL-60, as concentrações testadas (0,1-100 ?g/mL) induziram apoptose/necrose (PI+/AV+). A expressão do gene FAS e ativação das caspases 8 e 3 determinou a ativação da via extrínseca da apoptose na linhagem HL-60. A CR-LAAO promoveu algumas alterações na modulação do ciclo celular, sendo que nas linhagens tumorais os atrasos se concentraram nas fases G0/G1 e S do ciclo celular. Ademais, a CR-LAAO mostrouse bactericida contra as cepas S. aureus e E. coli, com maior especificidade para a cepa gram-positiva (S. aureus). Em análises de microscopia de transmissão, foi possível observar um desmantelamento da parede celular bacteriana. Após 6h de pré-incubação com C. albicans, a CR-LAAO foi capaz de inibir 80% do crescimento da levedura. A CR-LAAO mostrou-se também um bom agente leishmanicida contra as espécies L. infantum chagasi (IC50=16,66 ?g/mL) e L. braziliensis (IC50=24,47 ?g/mL) e inibiu o crescimento da forma promastigota do Trypanosoma cruzi (IC50=196,8 ?g/mL). Testes in vivo revelaram que a CR-LAAO promoveu inflamação local aguda, recrutando células inflamatórias como neutrófilos e induzindo a formação de citocinas (IL-6 e IL-1?) e mediadores lipídicos (LTB4 e PGE2). Os resultados obtidos sugerem que a CR-LAAO apresenta potencial biotecnológico evidente, com efeitos antiparasitários, fungicida, bactericida, bem como atividade antitumoral in vitro. Dessa forma, os resultados obtidos para a CR-LAAO fornecem subsídios importantes para o desenvolvimento de estratégias terapêuticas de ação direcionada, como quimioterápicos e antimicrobianos mais eficazes. / L-amino acid oxidases (LAAOs) isolated from snake venoms are targets of a large number of researches due to their numerous biological and pharmacological actions. The objective of this study was to functionally characterize the L-amino acid oxidase from the venom of Calloselasma rhodostoma (CR-LAAO) through the activities: bactericidal, fungicidal, leishmanicidal, trypanocidal, cytotoxic, inflammatory and analysis of gene expression and apoptotic proteins. CR-LAAO showed high cytotoxicity in HepG2 and HL-60 tumor cells, inducing about 80% cell death at the highest concentration tested (100 ?g/mL) and showing low toxicity in PBMC cells. It was observed that the protein induced apoptosis (AV+) in PBMC. In HepG2, lower concentrations (0.1-2.5 ?g/mL) caused apoptosis (AV+), while major concentrations (5-100 ?g/mL) caused apoptosis/necrosis (PI+/AV+). In HL-60, the concentrations tested (0.1-100 ?g/mL) induced apoptosis/necrosis (PI+/AV+). The FAS gene expression and activation of caspases 8 and 3 determined the activation of the extrinsic pathway of apoptosis in HL-60 cells. CR- LAAO promoted some changes in the modulation of the cell cycle, and delays in tumor cell lines were concentrated in G0/G1 and S cell cycle phases. In addition, CR-LAAO proved to be bactericidal against S. aureus and E. coli strains, with higher specificity for Gram-positive strains (S. aureus). In analyses of transmission electron microscopy, it was possible to observe a dismantling of the bacterial cell wall. After 6 hours of preincubation with C. albicans, CR-LAAO was able to inhibit 80% of growth of yeast. CR-LAAO also showed antiparasite potential against species L. chagasi infantum (IC50 = 16.66 ?g/mL) and L. braziliensis (IC50 = 24.47 ?g/mL) and inhibited the growth of Trypanosoma cruzi promastigote form (IC50 = 196.8 ?g/mL). In vivo tests revealed that CR-LAAO promotes acute local inflammation by recruiting inflammatory cells as neutrophils and by inducing the production of cytokines (IL-6 and IL-1?) and lipid mediators (PGE2 and LTB4). The results suggest that CR-LAAO presents evident biotechnological potential, with antiparasite, fungicidal, bactericidal and antitumor effects in vitro. Thus, the results obtained for CR-LAAO provide important information for the development of therapeutic strategies with directed action, such as more effective chemotherapeutic and antimicrobial agents.

Submitted by Maike Costa (maiksebas@gmail.com) on 2017-06-21T12:11:13Z No. of bitstreams: 1 arquivototal.pdf: 5280829 bytes, checksum: 081debefa3f10398a1c9461855ba5b9d (MD5) / Made available in DSpace on 2017-06-21T12:11:14Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 5280829 bytes, checksum: 081debefa3f10398a1c9461855ba5b9d (MD5) Previous issue date: 2015-07-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Two series based on the structure of 2,5-diaryl-1,3,4-oxadiazole were synthesized, 2-aryl-5-methyl-1,3,4-oxadiazole (1a,h) and 2-aryl-5- trifluoromethyl-1,3,4-oxadiazole (2a,e), and their biological activity were investigated. These compounds had their chemical structures characterized with spectrometric methods such as IR, 1H and 13C NMR. To characterize the compound 2-(2-acetoxyphenyl)-5-methyl-1,3,4- oxadiazole, it was necessary the use of two-dimensional NMR techniques (COSY, HMQC and HMBC) and his structural arrangement was analyzed by the crystallographic X-ray technique. Mass spectrometric investigation, unprecedented for this class of compound, was also performed. All compounds were tested against eight strains of Staphylococcus aureus, Escherichia coli and also against strains of Aspegilles fumigatus, Aspegilles flavus, Candida albicans, Candida albicans and Candida tropicalis. The results showed that compounds 1b, 1c, 1e, 1g, 2a and 2c, produced inhibition on the growth of species of bacteria and fungi, where the MIC was set between 512 to 1224 mg mL-1. While the compounds 1d, 1e, 1f, 1h, 2a and 2b were inactive, the compounds 1d, 1e, 1f, 1h, 2a and 2b reported a broad spectrum. / Duas séries do heterocíclico 1,3,4-oxadiazol foram sintetizadas, a 2-aril-5-metil-1,3,4-oxadiazol (1a, h) e a 2-aril-5-trifluormetil-1,3,4- oxadiazol (2a, e), obtendo cinco moléculas inéditas (1a, 1e, 2a, 2c e 2e). Todas as moléculas obtidas foram caracterizados pelas técnicas espectroscópicas de 1D de RMN 1H e 13C, IV e realizado o estudo inédito de espectroscopia de Massas. Para a caracterização do composto 2-(2- acetoxifenil)-5-metil-1,3,4-oxadiazol se fez necessário a utilização das técnicas bidimensionais de RMN COSY, HMQC e HMBC, bem como seu arranjo estrutural foi analisado pela técnica cristalográfica de Raios-X. Os oxadiazóis obtidos foram avaliadas frente a oito cepas de Staphylococcus aureus e Escherichia coli e oito cepas, incluindo, Aspegilles fumigatus ATCC 16913, Aspegilles flavus, Candida albicans, Candida albicans e Candida tropicalis. Os ensaios para avaliações da atividade biológica dos produtos foram realizados pela técnica de microdiluição em meio líquido, onde foi determinada a concentração Inibitória Mínima (CIM). Os resultados mostraram que os compostos (1b), (1c), (1e), (1g), (2a) e (2c), produziram inibição sobre o crescimento de espécies de bactérias e de fungos, onde a CIM ficou estabelecida entre 512 a 1224 mg/ml. Enquanto que os compostos 1d, 1e, 1f, 1h, 2a e 2b se apresentaram inativos. Já os compostos 1d, 1e, 1f, 1h, 2a e 2b relataram um amplo espectro.

As L-aminoácido oxidases (LAAOs) isoladas de peçonhas de serpentes são alvos de um grande número de pesquisas devido às suas inúmeras ações biológicas e farmacológicas. O objetivo do presente trabalho foi caracterizar funcionalmente a Laminoácido oxidase da peçonha de Calloselasma rhodostoma (CR-LAAO) por meio das atividades: bactericida, fungicida, leishmanicida, tripanomicida, citotóxica, inflamatória e análise da expressão de genes e proteínas apoptóticas. A CR-LAAO mostrou-se altamente citotóxica sobre as células tumorais HepG2 e HL-60, promovendo cerca de 80% de morte celular na maior concentração testada (100 ?g/mL) e apresentou baixa toxicidade sobre células PBMC. Foi possível observar que a proteína induziu apoptose (AV+) em PBMC. Em HepG2, as menores concentrações (0,1-2,5 ?g/mL) causaram apoptose (AV+), e as maiores (5-100 ?g/mL) causaram apoptose/necrose (PI+/AV+). Em HL-60, as concentrações testadas (0,1-100 ?g/mL) induziram apoptose/necrose (PI+/AV+). A expressão do gene FAS e ativação das caspases 8 e 3 determinou a ativação da via extrínseca da apoptose na linhagem HL-60. A CR-LAAO promoveu algumas alterações na modulação do ciclo celular, sendo que nas linhagens tumorais os atrasos se concentraram nas fases G0/G1 e S do ciclo celular. Ademais, a CR-LAAO mostrouse bactericida contra as cepas S. aureus e E. coli, com maior especificidade para a cepa gram-positiva (S. aureus). Em análises de microscopia de transmissão, foi possível observar um desmantelamento da parede celular bacteriana. Após 6h de pré-incubação com C. albicans, a CR-LAAO foi capaz de inibir 80% do crescimento da levedura. A CR-LAAO mostrou-se também um bom agente leishmanicida contra as espécies L. infantum chagasi (IC50=16,66 ?g/mL) e L. braziliensis (IC50=24,47 ?g/mL) e inibiu o crescimento da forma promastigota do Trypanosoma cruzi (IC50=196,8 ?g/mL). Testes in vivo revelaram que a CR-LAAO promoveu inflamação local aguda, recrutando células inflamatórias como neutrófilos e induzindo a formação de citocinas (IL-6 e IL-1?) e mediadores lipídicos (LTB4 e PGE2). Os resultados obtidos sugerem que a CR-LAAO apresenta potencial biotecnológico evidente, com efeitos antiparasitários, fungicida, bactericida, bem como atividade antitumoral in vitro. Dessa forma, os resultados obtidos para a CR-LAAO fornecem subsídios importantes para o desenvolvimento de estratégias terapêuticas de ação direcionada, como quimioterápicos e antimicrobianos mais eficazes. / L-amino acid oxidases (LAAOs) isolated from snake venoms are targets of a large number of researches due to their numerous biological and pharmacological actions. The objective of this study was to functionally characterize the L-amino acid oxidase from the venom of Calloselasma rhodostoma (CR-LAAO) through the activities: bactericidal, fungicidal, leishmanicidal, trypanocidal, cytotoxic, inflammatory and analysis of gene expression and apoptotic proteins. CR-LAAO showed high cytotoxicity in HepG2 and HL-60 tumor cells, inducing about 80% cell death at the highest concentration tested (100 ?g/mL) and showing low toxicity in PBMC cells. It was observed that the protein induced apoptosis (AV+) in PBMC. In HepG2, lower concentrations (0.1-2.5 ?g/mL) caused apoptosis (AV+), while major concentrations (5-100 ?g/mL) caused apoptosis/necrosis (PI+/AV+). In HL-60, the concentrations tested (0.1-100 ?g/mL) induced apoptosis/necrosis (PI+/AV+). The FAS gene expression and activation of caspases 8 and 3 determined the activation of the extrinsic pathway of apoptosis in HL-60 cells. CR- LAAO promoted some changes in the modulation of the cell cycle, and delays in tumor cell lines were concentrated in G0/G1 and S cell cycle phases. In addition, CR-LAAO proved to be bactericidal against S. aureus and E. coli strains, with higher specificity for Gram-positive strains (S. aureus). In analyses of transmission electron microscopy, it was possible to observe a dismantling of the bacterial cell wall. After 6 hours of preincubation with C. albicans, CR-LAAO was able to inhibit 80% of growth of yeast. CR-LAAO also showed antiparasite potential against species L. chagasi infantum (IC50 = 16.66 ?g/mL) and L. braziliensis (IC50 = 24.47 ?g/mL) and inhibited the growth of Trypanosoma cruzi promastigote form (IC50 = 196.8 ?g/mL). In vivo tests revealed that CR-LAAO promotes acute local inflammation by recruiting inflammatory cells as neutrophils and by inducing the production of cytokines (IL-6 and IL-1?) and lipid mediators (PGE2 and LTB4). The results suggest that CR-LAAO presents evident biotechnological potential, with antiparasite, fungicidal, bactericidal and antitumor effects in vitro. Thus, the results obtained for CR-LAAO provide important information for the development of therapeutic strategies with directed action, such as more effective chemotherapeutic and antimicrobial agents.

Made available in DSpace on 2016-08-19T12:56:30Z (GMT). No. of bitstreams: 1 Joao Reis Salgado Costa Sobrinho.pdf: 6509513 bytes, checksum: 84a1d776e834645d488bd62d78d1a5c0 (MD5) Previous issue date: 2008-01-17 / The Pimenta dioica Lindl, popularly known as Jamaican pepper, is a native tree from Central America and West India. The tree is a member of Mirtaceae family, can reach 6-15 meters and is found in large scale in Bahia state, northeast of Brazil. Its fruit has an essential oil with great economic value in international market, due its high eugenol level (major compound), which is largely used in chemical and pharmaceutical industries. In this work, it was extracted the essential oil from the leaves of Pimenta dioica Lindl by hydrodestilation process, using a Clevenger's modified system. Some physical properties were determined, like density constancy, refraction index, solubility, color and appearance. Ultra Violet Spectroscopy, FTIR and Mass Spectroscopy were used to identify the major components and these techniques confirmed the eugenol as main compound of Pimenta dioica Lindl. Through the method of external standard using CG, it was possible to quantify the eugenol in the oil. The concentration found was 74% and was confirmed by UV Spectroscopy with similar results. The application of the essential oil from Pimenta dioica Lindl and standard eugenol as bactericide agent as done by Bauer-Kirby method in Escherichia coli, Salmonella sp., Pseudomonas sp. and Vibrio parahaemolyticus. The antibiotics cefotaxima, sulfazotrim, oxacilina and vancomicina were applied as comparison group. The essential oil showed more effectiveness than all antibiotics tested for the microorganism V. parahaemolyticus. For Escherichia coli the oil wasn't so effective than sulfazotrim, but better than the others. The oil was less efficient than sulfazotrin and cefotaxima for the Salmonella sp. and Pseudomonas sp. respectively. In the comparison with all others antibiotics the essential oil showed better results. The eugenol component showed to be the main responsible for the biological action against these microorganisms. / A Pimenta dioica Lindl, conhecida popularmente como pimenta da jamaica, é uma árvore de 6 a 15 m de altura, que pertence à família das Mirtaceae e tem como origem a América Central e oeste da Índia. No Brasil, a planta é encontrada em larga escala no Estado da Bahia. Seu fruto e folhas contêm um óleo essencial de grande valor econômico no mercado internacional, devido ao alto teor de eugenol (seu composto majoritário) que é largamente utilizado nas indústrias químicas e farmacêuticas. Neste trabalho, promoveu-se a extração do óleo essencial das folhas da Pimenta dioica Lindl através do método de hidrodestilação, utilizando um sistema de Clevenger modificado. Algumas propriedades físicas foram avaliadas, como as constantes de densidade, índice de refração, solubilidade, cor e aparência. Através de técnicas espectrofotométricas de UV, espectrofotométricas de IV, cromatografia gasosa e espectrometria de massas foi possível identificar o eugenol como constituinte majoritário do óleo essencial das folhas da Pimenta dioica Lindl. Através do método de padrão externo usando a cromatografia gasosa foi possível quantificar o eugenol no óleo em uma concentração de 74%, concentração essa, confirmada pela técnica de espectrofotometria UV. Realizou-se também um estudo biológico através do método de Bauer-Kirby da ação do óleo essencial sobre as bactérias Escherichia coli, Salmonella sp., Pseudomonas sp. e Vibrio parahaemolyticus. Os antibióticos cefotaxima, sulfazotrim, oxacilina e vancomicina também foram testados sobre as mesmas bactérias para efeito de comparação. O óleo essencial se mostrou mais eficiente do que todos os antibióticos sobre a bactéria V. parahaemolyticus. Sobre a Escherichia coli o óleo foi menos efetivo que o sulfazotrim, mas melhor do que os outros antibióticos. Para a Salmonella e Pseudomonas sp. o óleo foi menos efetivo que o sulfazotrim e a cefotaxima, respectivamente. Na comparação com todos os outros antibióticos o óleo essencial mostrou melhores resultados. O eugenol se mostrou ser o principal responsável por esta atividade biológica sobre estes organismos.