Repositório Institucional - Unifesp :: Navegando por Palavras-chave "Antimicrobial"

Navegando por Palavras-chave "Antimicrobial"

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Somente Metadadados
Antimicrobial activity of biogenic silver nanoparticles, and silver chloride nanoparticles: an overview and comments
(Springer, 2016) Duran, Nelson; Nakazato, Gerson; Seabra, Amedea B. [UNIFESP]
The antimicrobial impact of biogenic-synthesized silver-based nanoparticles has been the focus of increasing interest. As the antimicrobial activity of nanoparticles is highly dependent on their size and surface, the complete and adequate characterization of the nanoparticle is important. This review discusses the characterization and antimicrobial activity of biogenic synthesized silver nanoparticles and silver chloride nanoparticles. By revising the literature, there is confusion in the characterization of these two silver-based nanoparticles, which consequently affects the conclusion regarding to their antimicrobial activities. This review critically analyzes recent publications on the synthesis of biogenic silver nanoparticles and silver chloride nanoparticles by attempting to correlate the characterization of the nanoparticles with their antimicrobial activity. It was difficult to correlate the size of biogenic nanoparticles with their antimicrobial activity, since different techniques are employed for the characterization. Biogenic synthesized silver-based nanoparticles are not completely characterized, particularly the nature of capped proteins covering the nanomaterials. Moreover, the antimicrobial activity of theses nanoparticles is assayed by using different protocols and strains, which difficult the comparison among the published papers. It is important to select some bacteria as standards, by following international foundations ( Pharmaceutical Microbiology Manual) and use the minimal inhibitory concentration by broth microdilution assays from Clinical and Laboratory Standards Institute, which is the most common assay used in antibiotic ones. Therefore, we conclude that to have relevant results on antimicrobial effects of biogenic silver-based nanoparticles, it is necessary to have a complete and adequate characterization of these nanostructures, followed by standard methodology in microbiology protocols.
Acesso aberto (Open Access)
Avaliação da segurança e eficácia "in vitro" da Cuscuta racemosa Martius
(Universidade Federal de São Paulo, 2017-07-04) Bertoluci, Raquel Silveira [UNIFESP]; Lopes, Patricia Santos [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
Cuscuta racemosa, Mart is a parasitic plant belonging to the family Convolvulaceae, known in Brazil for the popular synonymy of "cipó chumbo" and "yarn of eggs". It is popularly used for its anti-inflammatory and healing actions, applied to diuretic and digestive disorders and presents itself as an alternative of biodiversity for use in medicines and cosmetics. The present study verified the in vitro evaluation of the safety and efficacy of the Cuscuta racemosa extract for possible cosmetic and drug applications. Assays were carried out from crude extract and alkaloids fraction from Cuscuta racemosa to evaluate cytotoxicity, and phototoxicity, as well as determination of antimicrobial and antitumor activity. Cytotoxicity and phototoxicity assays were performed according to the standards recommended by the Organization for Economic Co-operation and Development (OECD) using 3T3 BALB cells. Microbiological analyzes were conducted with Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The evaluation of antimicrobial activity was performed in liquid and solid media. Antitumor activity assays were performed with the HeLa, MDA-DB and Sk-Mel lines. Cytotoxicity tests revealed a cytotoxic effect of the crude extract at concentrations of 34.01 and 50 mg / mL, but at lower concentrations did not present significant action, indicating its safety for possible cosmetic and medicinal applications. Both samples tested showed no phototoxicity. The lethal dose estimated at 50% of the cells calculated for the crude extract was 352.25mg / kg. With respect to the antimicrobial activity, the samples did not present zone of inhibition in solid culture medium in the concentrations tested for none of the tested microorganisms. The crude extract was cytotoxic in all its concentrations in tumor lines. The results indicate the possibility of using the samples in cosmetics, since the alkaloid fraction showed absence of phototoxicity and absence of cytotoxicity, although the samples did not present significant antimicrobial in the concentrations tested. With respect to antitumor activity, complementary studies are necessary directing the active only to the place of action, minimizing the risks of performance of the extract in normal cells.
Acesso aberto (Open Access)
Avaliação das metodologias M.I.C.E.®, Etest® e microdiluição em caldo para determinação da CIM em isolados clínicos
(Sociedade Brasileira de Patologia ClínicaSociedade Brasileira de PatologiaSociedade Brasileira de Citopatologia, 2011-04-01) Campana, Eloiza Helena [UNIFESP]; Carvalhaes, Cecília Godoy [UNIFESP]; Barbosa, Paula Peraro [UNIFESP]; Machado, Antonia Maria De Oliveira [UNIFESP]; Paula, Ana Maria De; Gales, Ana Cristina [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Thermo Fisher Scientific Divisão de Microbiologia Brasil
INTRODUCTION: The Oxoid® M.I.C.EvaluatorTM methodology (M.I.C.E., Thermo Fisher Scientific, Basingstoke, UK), recently released into the market, represents a rapid alternative to antimicrobial susceptibility testing. OBJECTIVE: The objective of this study was to evaluate the performance of M.I.C.E. methodology in relation to broth microdilution (reference test) and Etest® (BioMérieux, Marcy l'Étoile, France). Material and method: A total of 160 bacterial isolates were collected comprising the following species: P. aeruginosa (20), Acinetobacter spp. (20), K. pneumoniae (20), E. coli (20), S. aureus (20), coagulase-negative Staphylococcus (20), E. faecalis (20) and E. faecium (20). Following Clinical Laboratory Standands Institute (CLSI) standards (2009) and the manufacturers' recommendations, antimicrobial susceptibility testing was performed using broth microdilution method, Etest and M.I.C.E. The results were interpreted according to the criteria established by CLSI and compared through regression analysis. RESULTS: All antimicrobial combinations vs. bacterial species were evaluated and M.I.C.E. methodology yielded good results with general correlation (MIC variation ± 1-log2) > 90%, except for cefotaxime (85%) and vancomycin (76.3%) when compared with the reference method. The M.I.C.E. results compared to Etest showed general correlation (> 96%), except for amoxicillin/clavulanic acid (67.5%) combination. CONCLUSION: AST results obtained from M.I.C.E. methodology showed a good correlation with those from broth microdilution and Etest, which corroborates its time effectiveness in the determination of MIC. However, the combination of amoxicillin/clavulanic acid requires further attention.
Somente Metadadados
Combined bactericidal activity of silver nanoparticles and hexadecylpyridinium salicylate ionic liquid
(Springer, 2015-03-10) Silveira, Leonardo T. [UNIFESP]; Liberatore, Ana Maria A. [UNIFESP]; Koh, Ivan H. J. [UNIFESP]; Bizeto, Marcos A. [UNIFESP]; Camilo, Fernanda F. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
Recently, ionic liquids have been used as dispersing agents for silver nanoparticle (AgNP) preparation. in this paper, we have shown a simple method to prepare AgNP in aqueous media using an ionic liquid called hexadecylpyridinium salicylate (HDPSal) as dispersing agent. the dispersions were produced by the chemical reduction of silver ions in aqueous media with different concentrations of HDPSal and tetrabutylammonium borohydride as reducing agent. the UV-Visible electronic spectra showed the characteristic plasmonic resonance band around 420 nm, confirming the formation of AgNPs. the TEM images confirmed the formation of spherical particles with diameters lower than 10 nm. the charge of these particles was determined by Zeta potential and they were around +50 mV, indicating that the HDP cations are surrounding the AgNPs, avoiding their agglomeration. Most of the dispersions remained stable for at least 1 month. Microbiological assays showed that the combination of AgNP with HDPSal results in wider range of antimicrobial effect.
Acesso aberto (Open Access)
Estudo da interação de Sakuranetina em modelos de membrana celular através de filmes de Langmuir
(Universidade Federal de São Paulo, 2021) Pires, Guilherme Henrique da Cruz Ramos [UNIFESP]; Caseli, Luciano [UNIFESP]; http://lattes.cnpq.br/8929162910172931; http://lattes.cnpq.br/6486721397875016
Neste trabalho, estudou-se a interação de uma substância com possível ação microbicida, sakuranetina, com filmes de Langmuir de fosfolipídios, o qual serviram como modelos simples de membrana celular. Os fosfolipídios empregados foram o dipalmitoil fosfatidilcolina (DPPC) e o dipalmitoil fosfatidil etanolamina (DPPE), coespalhados com o bioativo. Avaliou-se a interação da sakuranetina com as monocamadas de fosfolipídios por meio de medidas de pressão de superfície, microscopia no ângulo de Brewster e espectroscopia no infravermelho. Os resultados permitem inferir que a Sakuranetina apresenta potencial de interação com as monocamadas de DPPC e DPPE devido à expansão do filme, com a possível penetração do composto na monocamada lipídica. Além disso, a Sakuranetina alterou os espectros de infravermelho, alterando tanto a região hidrofóbica como hidrofílica, sugerindo interações moleculares com estes grupos, bem como altera a morfologia das monocamadas lipídicas, como observado por microscopia no ângulo de Brewster. Acredita-se que os resultados aqui obtidos contribuirão no aprimoramento da compreensão dos mecanismos envolvidos na interação da sakuranetina com membranas de eritrócitos e bactérias gram-negativas, bem suas implicações biológicas.
Acesso aberto (Open Access)
Estudo de nanopartículas metálicas e bimetálicas para aplicações em medicina e agricultura
(Universidade Federal de São Paulo, 2024-02-29) Lopes, Isabela Santos [UNIFESP]; Courrol, Lilia Coronato [UNIFESP]; Caseli, Luciano [UNIFESP]; http://lattes.cnpq.br/892916291017293; http://lattes.cnpq.br/7225675813566195; http://lattes.cnpq.br/8652646215861192
Este trabalho descreve a síntese, caracterização e aplicação de nanopartículas (NPs) de prata, cobre e ouro, sintetizadas por fotorredução com os aminoácidos ácido aminolevulínico (ALA) e sua forma metilada ácido aminolevulinato de metila (MALA) e o ácido gama aminobutírico (GABA). As nanopartículas foram caracterizadas por espectroscopia no UV-Vis, microscopia eletrônica de transmissão (MET), potencial Zeta, espectroscopia do infravermelho por transformada de Fourier (FTIR) e microscopia de força atômica. O potencial de aplicação das nanopartículas sintetizadas na agricultura e medicina foi avaliado. Os resultados analisados mostram nanopartículas em tamanho nanométrico com alta estabilidade coloidal com potencial Zeta negativo acima de -25.0 mV, formato esférico no caso das nanopartículas de prata, cobre e ouro com ALA, MALA, GABA e ALAGABA. As nanopartículas de prata e cobre foram aplicadas em nanopriming com sementes de girassol. Resultados de fluorescência da clorofila, decaimento do tempo de vida, fator de crescimento da planta e percentual de germinação foram obtidos e mostraram o aumento da intensidade de fluorescência da clorofila e no fator de crescimento das mudas em comparação com sementes tratadas com água. A eficácia das nanopartículas de prata e cobre como agentes antimicrobianos foi testada as com as bactérias E. coli e S. aureus e os fungos fitopatogênicos A. grandis, C. truncatum, C. cassiicola e F. oxysporum. A citotoxicidade das NPs de ouro revestidas com ALA, MALA e GABA foram estudadas em células MCF-7 para a realização da terapia com raio x de baixa energia. Com este trabalho obtivemos uma melhor compreensão dos mecanismos envolvidos no processo de síntese das NPs, nas aplicações médicas e o papel fundamental da atuação das NPs de ouro com ALA, MALA e GABA. NPs de prata e cobre se mostraram promissoras como carreadores do ALA e GABA para a célula vegetal, com ação antimicrobiana satisfatória contra as bactérias e fungos estudados e em nanopriming de sementes.
Acesso aberto (Open Access)
Evaluation of antimicrobial and antitumoral activity of Garcinia mangostana L. (mangosteen) grown in Southeast Brazil
(Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia, 2014-01-01) Cunha, Bruna Lais Almeida; França, Jerônimo Pereira de [UNIFESP]; Moraes, Andrea Aparecida Fátima Souza [UNIFESP]; Chaves, Alba Lucilvânia Fonseca; Gaiba, Silvana; Fontana, Renato; Sacramento, Celio Kersul do; Ferreira, Lydia Masako [UNIFESP]; França, Lucimar Pereira de; Universidade Estadual de Santa Cruz Department of Biological Sciences; Universidade Estadual de Santa Cruz Departament of Agricultural and Environmental Sciences; Universidade Federal de São Paulo (UNIFESP)
PURPOSE:To characterize the anatomy of the fruit and leaf and the presence of phytocompounds. To evaluate the antitumor and antimicrobial activity of ethanolic extract of Garcinia mangostana L. (mangosteen) cultivated in southeastern Brazil.METHODS:Anatomical characterization and histochemical reactions were performed for structural identification and the presence of phytocompounds. Preparation of ethanolic extract of the fruit, leaf and resin of mangosteen. Culture B16-F10 melanoma cells for treatment with mangosteen ethanolic extract to determine cell viability by MTT and genotoxic effect by comet assay. Evaluation by antimicrobial activity against Staphylococcus aureus and Escherichia coli by agar diffusion test and by determination of Minimum Inhibitory Concentration (MIC).RESULTS:Our results showed many secretory canals in resin fruit and leaf; identifying lipids, starch, lignin and phenolic compounds. The leaf extract induced genotoxicity and apoptosis in B16-F10 cells, since the fragmentation of DNA in the comet assay. The ethanolic extract of mangosteen obtained in the resin, leaf and fruit showed antimicrobial activity against Staphylococcus aureus and Escherichia coli with a MIC at 0.1 mg/mL.CONCLUSION: In conclusion, we have demonstrated both antimicrobial and antitumor activity of ethanol extract of mangosteen emphasizing its therapeutic potential in infectious diseases and in cancer, such as melanoma.
Restrito
Evaluation of antitumoral and antimicrobial activity of Morinda lcitrifolia L. grown in Southeast Brazil
(Acta Cirurgica Brasileira, 2014-01-01) Candida, Thamyris; Franca, Jeronimo Pereira de; Fonseca Chaves, Alba Lucilvania; Rodrigues Lopes, Fernanda Andrade; Gaiba, Silvana; Sacramento, Celio Kersul do; Ferreira, Lydia Masako [UNIFESP]; Franca, Lucimar Pereira de; Universidade Estadual Santa Cruz; Universidade Estadual Santa Cruz; Universidade Federal de São Paulo (UNIFESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico; Fundação Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
PURPOSE: To evaluate the antitumor and antimicrobial activity of ethanolic extract of Morinda citrifolia L. fruit cultivated in southeastern Brazil.METHODS: Preparation ethanolic extract of the fruit of Morinda citrifolia L. Culture of melanoma cells B16-F10 for treatment with ethanolic extract of Morinda citrifolia L. fruit to determine cell viability by MTT and determination temporal effect of ethanolic extract fruit on the cell growth B16-F10 for 8 days. Evaluation of antimicrobial activity of ethanolic extract fruit against Staphylococcus aureus and Escherichia coli by determination of Minimum Inhibitory Concentration (MIC).RESULTS: the ethanolic extract of Morinda citrifolia L. fruit (10mg/mL) decreased cellular activity and inhibited 45% the rate of cell proliferation of B16-F10 melanoma treated during period studied. the ethanolic extract of Morinda citrifolia L. fruit demonstrated antimicrobial activity inhibiting the growth of both microorganisms studied. Staphylococcus aureus was less resistant to ethanolic extract of Morinda citrifolia L. fruit than Escherichia coli, 1 mg/mL and 10 mg/mL, respectively.CONCLUSION: What these results indicate that the ethanolic extract of the fruit of Morinda citrifolia L. showed antitumor activity with inhibition of viability and growth of B16-F10 cells and also showed antibacterial activity as induced inhibition of growth of Staphylococcus aureus and Escherichia coli.
Embargo
Filmes de quitosana contendo óleo essencial de capim-limão (Cymbopogon citratus) com aplicação cosmética em potencial
(Universidade Federal de São Paulo, 2022-01-31) Gaspar, Ana Laura [UNIFESP]; Yoshida, Cristiana Maria Pedroso [UNIFESP]; Lopes, Patricia Santos [UNIFESP]; http://lattes.cnpq.br/7939687315116927; http://lattes.cnpq.br/3546808357732166; http://lattes.cnpq.br/0212509295394830
A preocupação com resíduos ambientais e o interesse dos consumidores e da indústria cosmética em alternativas sustentáveis vêm incentivando pesquisas voltadas, por exemplo, aos produtos de cuidado com a pele, conhecidos como “anti-aging”, cuja matéria-prima seja sustentável. A quitosana, polímero caracterizado pela biodegradabilidade, baixa toxicidade, flexibilidade e propriedades antimicrobianas, quando associada ao óleo essencial de capim-limão (LO), com suas propriedades antioxidantes e antimicrobianas, pode ser potencialmente aplicada nesse cenário. Concentrações de LO de 0, 0,5, 1,0, 1,5% (m/m) foram incorporadas à matriz filmogênica de quitosana, formando os filmes ativos (CLO). Suas propriedades antioxidantes e permeabilidade ao vapor de água aumentaram em função da concentração de LO. CLO 0,5% apresentou viabilidade celular acima de 70% e CLO 1,5% teve a mesma capacidade do controle antioxidante positivo NAC (N-acetil-L-cisteína) para inativar espécies reativas de oxigênio intracelular (ROS) em células HaCat não tratadas com H2O2 . Os filmes ativos também apresentaram atividade antimicrobiana, no local de contato da aplicação, contra Escherichia coli e Staphylococcus aureus. Filmes biodegradáveis de quitosana e óleo essencial de capim-limão apresentaram aplicação sustentável em potencial na indústria cosmética de cuidados com a pele, formando máscaras tópicas com flexibilidade, permeabilidade seletiva e capacidade antioxidante.
Somente Metadadados
Funcionalização De Nanopartículas Metálicas Com Diferentes Combinações De Peptídeos Para Aplicações Como Agentes Antimicrobianos E Antitumorais
(Universidade Federal de São Paulo (UNIFESP), 2017-11-27) Formaggio, Daniela Maria Ducatti [UNIFESP]; Tada, Dayane Batista [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
Metal nanoparticles (NPs) have showing promising applications in the biomedical field. These NPs have unique physicochemical properties, as well as great chemical versatility on their surface, which allows new modifications and incorporations of different molecules. In addition, they have the advantage of accumulating preferentially in tumor tissues due to the enhanced permeability and retention effect, known as EPR. The incorporation of therapeutic peptides to the surface of metallic NPs could be a promising strategy to improve their applications as therapeutic molecules. Peptides are highly selective molecules. However, they are also vulnerable to some in vivo pharmacologic barriers limiting their effective action, including low bioavailability or deactivation by enzymes. In this work, three types of metal NPs were prepared: gold NPs (AuNPs), silver NPs (AgNPs) and bimetallic NPs composed by gold and platinum (AuPtNPs). NPs were characterized by ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS), transmission electron microscopy (TEM), inductively coupled plasma optical emission spectroscopy (ICP-OES) and X-ray diffraction (XRD). Aiming at biomedical applications, NPs were firstly evaluated regarding their toxicity by cell viability assays using human fibroblast cells (HS68 cell line) and embryonic toxicity test in zebrafish (Danio rerio). The assays showed better biocompatibility of AuNPs compared to AgNPs and AuPtNPs. Thus, AuNPs were studied as carriers of antitumor and antimicrobial peptides as an alternative approach of overcoming the pharmacokinetic limitations inherent in these molecules. Two peptides derived from complementary monoclonal antibodies (CDRs) with amino acid sequences YISCYNGATSYNQKFK (C7H2) and RASQSVSSYLA (HuAL1) were previously identified by collaborators of this project demonstrating excellent toxicity against tumor cells, antimetastatic activity as well as a potent antimicrobial activity. The peptides were individually conjugated to the AuNPs surface, forming the AuNPsC7H2 and AuNPsHuAL1 NPs. The peptides were also linked together forming the AuNPsC7H2HuAL1. The in vitro results suggested an improved antitumor activity for AuNPsHuAL1 and AuNPsC7H2HuAL1 against metastatic melanoma tumor cell line (B16F10-Nex2) compared to the peptides in solution. In vivo, the peptide combination of HuAL1 and C7H2 was even more efficient when linked to AuNPs. The antimicrobial activity of the three NPs separately as well as the peptide functionalized AuNPs were also evaluated employing microdilution test against strains of Candida Albicans, Pseudomonas aeruginosa and Staphylococcus aureus. The results confirm an intrinsic antimicrobial action of the three metal NPs and an optimal antibiotic action for AuNPsHuAL1.
Somente Metadadados
Implementation of an antibiotic prophylaxis protocol in an intensive care unit
(Elsevier B.V., 2012-10-01) Almeida, Silvana Maria de; Marra, Alexandre R.; Wey, Sergio B. [UNIFESP]; Victor, Elivane da Silva; Pavao dos Santos, Oscar Fernando; Edmond, Michael B.; Hosp Israelita Albert Einstein; Universidade Federal de São Paulo (UNIFESP); IIEP; Virginia Commonwealth Univ
Background: When properly employed, the prophylactic use of antimicrobials is associated with a reduction in surgical site infections (SSIs). We found that the appropriate use of antimicrobial prophylaxis was only 50.5% (53/105) among patients undergoing surgery in the adult intensive care unit of our hospital. in 2001, a protocol was designed to improve compliance with recommended practice.Methods: We used a prospective interventional study and a case control study carried out between 2001 and 2007, including follow-up and daily intervention to improve compliance with antimicrobial prophylaxis guidelines and to monitor antimicrobial consumption and SSI rates. Cases of noncompliance to the prophylaxis protocol (group I) were matched to controls (group II) with appropriate prophylaxis and compared with regards to type of surgery, operative duration, intraoperative antimicrobial use, type of antimicrobial used, length of hospital stay, severity of illness, comorbidities, invasive devices, possible adverse reactions, and death.Results: Compliance with antimicrobial prophylaxis metrics reached 85%; however, we were unable to detect a change in SSI rate or consumption and cost of antimicrobials. Inappropriate use was not associated with higher likelihood of death. There were no other significant differences between the 2 groups.Conclusion: Our intervention increased compliance with appropriate antimicrobial surgical prophylaxis with no negative impact on patient safety. Copyright (C) 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
Somente Metadadados
Inhibition of bacterial and fungal pathogens by the orphaned drug auranofin
(Future sci ltd, 2016) Fuchs, Beth Burgwyn; RajaMuthiah, Rajmohan; Souza, Ana Carolina Remondi [UNIFESP]; Eatemadpour, Soraya; Rossoni, Rodnei Dennis; Santos, Daniel Assis; Junqueira, Juliana C.; Rice, Louis B.; Mylonakis, Eleftherios
Background: We identified auranofin as an antimicrobial compound utilizing a high-throughput screen using a Caenorhabditis elegans-Staphylococcus aureus infection model. Results/methodology: Treatment of infected nematodes with auranofin resulted in a prolonged survival rate of 95%, reached with 0.78 mu g/ml. Further investigation of the antimicrobial activity of auranofin found inhibition against S. aureus, Enterococcus faecium and Enterococcus faecalis. Importantly, the fungal pathogens Cryptococcus neoformans was also effectively inhibited with an MIC at 0.5 mu g/ml. Auranofin appears to target the thioredoxin system. Conclusion: This work provides extensive additional data on the antibacterial effects of auranofin that includes both reference and clinical isolates and reports a novel inhibition of fungal pathogens by this compound.
Somente Metadadados
A new method for producing highly concentrated non-aqueous dispersions of silver nanoparticles and the evaluation of their bactericidal activity
(Springer, 2014-11-01) Oliveira, Roselaine da S. [UNIFESP]; Bizeto, Marcos A. [UNIFESP]; Liberatore, Ana M. A. [UNIFESP]; Koh, Ivan H. J. [UNIFESP]; Camilo, Fernanda F. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
Different preparation methods of silver nanoparticles (AgNP) are well described in the literature, most of them in aqueous medium. Aqueous dispersions of AgNP normally have a limited capacity to tolerate high nanosilver concentrations. However, AgNP production in non-aqueous medium is still scarce although its exploitation for example, as coating for hydrophobic surfaces, would be of a huge importance in many technological applications. in this work, we report the chemical preparation of highly concentrated non-aqueous AgNP dispersions obtained by reduction of silver cation, from two distinct salt sources (AgNO3 and AgBF4), by 1-butanol in the presence of a biocompatible poly(ether-block-amide) copolymer, named PEBA. the highest concentration reached was around 5 mM, when it used AgBF4 as silver source and 4 % (w/w) of a PEBA solution in 1-butanol. This AgNP concentration is notably higher than the values reported in aqueous medium. the AgNP formation was attested by UV-Vis spectroscopic analysis, which showed the characteristic strong plasmon band at 420 nm. the X-ray diffraction patterns confirmed the formation of a crystalline fcc silver metallic phase with particle diameters ranging from 5 to 10 nm accordingly to transmission electron microscopy examination. It was also observed that the AgNP dimensions are dependent on the PEBA and silver salt concentrations. the AgNP dispersions presented a very high antimicrobial activity against E. coli and S. aureus microorganisms, even in low concentration, attested by the Kirby-Bauer method.
Somente Metadadados
Ozonated mineral oil: preparation, characterization and evaluation of the microbicidal activity
(Korean Acad Asthma Allergy & Clinical Immunology, 2016) Iorio, Fernanda B. R. D. [UNIFESP]; Liberatore, Ana M. A. [UNIFESP]; Koh, Ivan H. J.; Otani, Choyu; Camilo, Fernanda F. [UNIFESP]
The ozonation of vegetable oils has been studied, since the produced ointments have antibacterial and fungicidal activities. However, the ozonation of mineral oils has not been reported in the literature yet, opening an interesting field for examination. In this work, we have shown the ozonation of a commercial mineral oil (Nujol). The main goal was to produce oils containing free ozone, so that this gas could act as antimicrobial agent. It was found that in Nujol, ozone remains for at least 40days and in the sample ozonized for 15h its concentration was 7.5mgmL(-1). Neat Nujol showed no antimicrobial activity against the tested microorganisms, however, when ozonated it showed antimicrobial activity against Enterococcus faecalis, Staphylococcus aureus and Escherichia coli.
Acesso aberto (Open Access)
Peptídeos bioativos: uma oportunidade para inovação em saúde e desenvolvimento de alimentos funcionais
(Universidade Federal de São Paulo, 2025-01-16) Santos, Yasmim Lima Vicente dos [UNIFESP]; Venturini, Anna Cecília [UNIFESP]; http://lattes.cnpq.br/8531229038363609
Nos últimos anos, o aumento das doenças crônicas não transmissíveis e o interesse por uma alimentação que favoreça a saúde a longo prazo impulsionaram as pesquisas sobre peptídeos bioativos. Evidências científicas recentes sugerem que as proteínas alimentares não servem apenas como nutrientes, mas também podem modular as funções fisiológicas do corpo. Os peptídeos bioativos são pequenas cadeias de aminoácidos que podem ser obtidas através de processos como digestão enzimática, fermentação microbiana, processos digestivos no trato gastrointestinal ou síntese laboratorial e que possuem potenciais benefícios biológicos, como efeitos antimicrobianos, anti-inflamatórios, anticarcinogênicos, anti-hipertensivos, antitrombóticos, antioxidante, antiobesidade, antidiabetes, opióide e antienvelhecimento. Essas funções fisiológicas são reguladas principalmente por alguns peptídeos que são criptografados nas sequências de proteínas nativas. Esses compostos se encontram naturalmente em alimentos como leite, carnes, peixes, vegetais e algas. Suas moléculas, ao serem liberadas por processos específicos, desempenham funções que contribuem para a saúde, como regulação do metabolismo e modulação do sistema imunológico e, portanto, são considerados compostos bioativos para o desenvolvimento de nutracêuticos ou alimentos funcionais. Por serem de origem natural, apresentam menos efeitos adversos que medicamentos que se encontram no mercado atualmente, podendo vir a ser útil no futuro. No entanto, a aplicação comercial desses peptídeos bioativos foi adiada devido à ausência de métodos de produção apropriados e escaláveis, exploração adequada dos mecanismos de ação, alta digestibilidade gastrointestinal (levando a uma biodisponibilidade baixa), taxa de absorção variável e a falta de ensaios clínicos bem projetados para fornecer evidências substanciais para potenciais alegações de saúde. Entretanto, ainda há muito que se estudar sobre os mecanismos de ação para fornecer evidências substanciais sobre potenciais alegações de saúde. Este artigo de revisão explora as propriedades e os mecanismos de ação dos peptídeos bioativos, destacando seus potenciais benefícios para a saúde e aplicações na indústria farmacêutica e alimentícia.

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