21 research outputs found
Encapsulação de óleo de cravo em nanopartículas lipídicas e poliméricas em sistema livre de solvente
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Química, Florianópolis, 2016.A nanoencapsulação é utilizada para melhora da solubilidade de óleos essenciais em meios aquosos e aumentar a biodisponibilidade devido ao aumento da superfície de contato. Neste trabalho, foram produzidas nanoemulsões, nanopartículas lipídicas sólidas e nanopartículas poliméricas carregadas com óleo de cravo e avaliada a sua eficiência após o processo de encapsulação. As nanoemulsões foram formadas a partir da técnica de ultrasonicação, utilizando Crodamol, Pluronic® F-127 e diferentes concentrações de óleo de cravo, foram formadas nanopartículas esféricas de diâmetro médio entre 98 e 134 nm com a variação da concentração de óleo. As nanopartículas lipídicas sólidas foram produzidas através do método de emulsificação-ultrasonicação utilizando ácido esteárico, ou mistura de ácido esteárico com Crodamol e variação da concentração de óleo de cravo. O tamanho médio das partículas se manteve inferior a 312 nm, com formato esférico e com formação de imperfeições cristalinas na superfície das nanopartículas. As nanopartículas formadas com dois lipídios tiveram maior eficiência de encapsulação e maior retenção do óleo essencial após estocagem, em comparação às compostas por somente ácido esteárico. Análises de FT-IR e DSC comprovaram a redução da cristalinidade com a adição do lipídio líquido na formulação, devido à formação de mais imperfeições na rede cristalina do ácido graxo, consequentemente mais espaço para acomodação e retenção do composto bioativo. A formulação de nanoemulsão testada obteve um valor de Concentração Inibitória Mínima inferior às formulações testadas para nanopartículas lipídicas sólidas, e todas as formulações testadas obtiveram ótimos valores de atividade antioxidante. As nanopartículas poliméricas carregadas com óleo de cravo foram produzidas através do método de polimerização via tiol-eno em miniemulsão, utilizando um monômero dieno renovável derivado de óleo de mamona e isosorbídeo, um monômero ditiol, Lutensol AT 80 como surfactante não-iônico e diferentes concentrações de óleo de cravo. As nanopartículas produzidas apresentaram um diâmetro médio em intensidade entre 192 e 284 nm, com alta eficiência de encapsulação. A conversão final do monômero apresentou elevado decréscimo com o aumento da concentração de óleo de cravo na formulação. Este resultado é devido à reação do grupo fenol do eugenol com os radicais livres diminuindo a concentração destes no meio reacional com consequente redução da taxa de polimerização. Análises de DSC e GPC sugerem que o óleo de cravo foi parcialmente incorporado à cadeia polimérica, devido à redução do ponto de fusão eda massa molar do polímero formado na presença de óleo de cravo na formulação. A reação pode se dar devido à reação do radical tiil com a insaturação do grupo alquila da molécula de eugenol formando uma ligação covalente entre a cadeia polimérica em crescimento e o eugenol. Por conter apenas uma insaturação em sua molécula, o eugenol age com um agente terminador de cadeia deste processo de polimerização, ocasionando a redução da massa molar do polímero formado. As baixas massas molares alcançadas e a incorporação da molécula de eugenol à cadeia polimérica reduzem também a temperatura de fusão do polímero, conforme observado por DSC. Na avaliação da atividade antioxidante foi verificado que a presença de óleo de cravo elevou a atividade antioxidante das nanopartículas.Abstract: Nanoencapsulation is used to improve water solubility of essential oils in aqueous media and improve bioavailability due to the increase of contact area. In this work were produced nanoemulsions, solid lipid nanoparticles and polymeric nanoparticles loaded with clove oil and evaluated its efficiency after encapsulation process. Nanoemulsions were prepared through ultrasonication technique, using Crodamol, Pluronic® F-127 and different clove oil concentration; spherical nanoparticles were formed with average diameter between 98 and 134 nm when the oil concentration was varied. The solid lipid nanoparticles were produced using stearic acid or mixture of stearic acid and Crodamol, both cases was tested with clove oil concentration varying. The average particle size remained below 312 nm, with spherical shape and formation of crystalline imperfections on the surface of the nanoparticles. The samples tested with two lipids had higher encapsulation efficiency and better clove oil retention after storage than those composed by just one lipid. FT-IR and DSC analyses confirmed a reduction in lipid crystallinity when liquid lipid was added in formulation; it is because the liquid lipid is able to form more imperfections in the crystal lattice of fatty acid, consequently more room available to accommodation and retention of bioactive compound. The nanoemulsion formulation tested had a low Minimum Inhibitory Concentration than those formed with solid lipid, and all formulations tested showed a great antioxidant activity. Polymeric nanoparticles loaded with clove oil were produced by thiol-ene polymerization in miniemulsion, using a fully renewable diene monomer derived from castor oil and isosorbide, a dithiol monomer, Lutensol AT 80 as non ionic surfactant and different concentrations of clove oil. The polymeric nanoparticles presented an intensity average diameter between 192 and 284 nm with high encapsulation efficiency. The final polymer conversion showed a decrease with increasing concentration of clove oil in the formulation. This result could be attributed to the reaction of the phenyl group of eugenol with the free radicals decreasing their concentration in the reaction medium and thus the polymerization rate. DSC and GPC analyses suggested that the clove oil (eugenol) was partially incorporated to the polymer chain due to the decrease of the melting point and molecular weight of the polymer in the presence of clove oil in the formulation. This reaction can occur due to the reaction of the thyil radical with the double bond of the alkyl group from the molecule of eugenol creating a covalent bond between the growingpolymer chain and the eugenol. As eugenol contains just one insaturation, it acts as a capping agent for this polymerization process, resulting in the decrease of the molecular weight of the polymer that is being formed. The reduced molecular weight and the incorporation of eugenol to the polymer chain decrease the melting point as observed by DSC. The antioxidant activity evaluation showed that the presence of clove oil improve the antioxidant activity of nanoparticles
Encapsulation of clove oil in nanostructured lipid carriers from natural waxes: Preparation, characterization and in vitro evaluation of the cholinesterase enzymes
Eugenol is a phenolic compound largely found in the clove essential oil that possesses promising biological activity.
However, its low water solubility is a major concern and encapsulation is an alternative to improve water affinity.
The objective of this work was to produce nanostructured lipid carriers (NLC) by hot homogenization/ultrasound
emulsification and to evaluate the effect of free and encapsulated clove oil on the in vitro cholinesterase enzymes
modulation using Drosophila melanogaster (DM) tissue. The NLC composed of a natural wax (carnauba or beeswax)
and crodamol showed an average diameter between 121 and 367 nm with good dispersion and colloidal stability.
The spherical shape and solid character together with the semi-crystalline environment confirm the formation of
NLC. DSC analysis indicated polymorphic transition events of the waxes. In vitro tests using DM demonstrated that free clove oil showed a good inhibition of the butyryl and acetylcholinesterase enzymes above a concentration of
10 mM, with IC50 values of 4.3 and 3.5 mM, respectively. The dispersions of the NLC loaded with clove oil showed
a decrease in the IC50 enzymes values, indicating the preservation of the clove essential oil and suggesting an
increased in the solubility. Results indicate that NLC dispersions have good potential to be used for foods and
cosmetic aqueous formulations possessing biological activity.Authors thank the financial support from CAPES (Coordenação de
Aperfeiçoamento de Pessoal de Nível Superior) and CNPq (Conselho
Nacional de Desenvolvimento Científico e Tecnológico), and also
Laboratório Central de Microscopia Eletrônica of Universidade Federal
de Santa Catarina (LCME/UFSC) for TEM analyses.info:eu-repo/semantics/publishedVersio
SABER TREINAR A SI MESMO: PORQUE E COMO DEVEMOS ENSINAR TREINAMENTO NAS AULAS DE EDUCAÇÃO FÍSICA?
O texto apresenta argumentações cientificas sobre o treino corporal na escola a partir de uma experiência concreta na Escola Municipal Teodoro Sampaio, Salvador, Bahia, Brasil
Recommended from our members
Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
Recommended from our members
Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
The original version of this article unfortunately contained a mistake
Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
Green synthesis of benzyl esters mediated by enzymatic biocatalysts using different reactor configurations
Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Química, Florianópolis, 2019.Este trabalho visou a síntese dos ésteres aromáticos propionato de benzila, butirato de benzila e benzoato de benzila mediada por enzimas imobilizadas como biocatalisadores. A enzima Novozym 435 apresentou o melhor desempenho para a síntese dos ésteres propionato e butirato benzila em sistemas livres de solvente enquanto a enzima Lipozyme TL IM mostrou a melhor performance na síntese do benzoato de benzila. Um planejamento experimental 2² foi empregado para maximizar a conversão dos ésteres propionato e butirato de benzila utilizando ácido e álcool como substratos da reação de esterificação. A síntese do propionato de benzila em batelada atingiu uma conversão máxima de 44 % e quando a configuração batelada alimentada foi utilizada para mesma razão molar de substratos (1:1) a conversão aumentou para 90 %, indicando que a alimentação controlada do ácido durante as primeiras horas de reação reduziu os seus efeitos inibitórios. Além disso, as micrografias ópticas do suporte da Novozym 435 mostraram que o ácido propiônico agiu como um forte detergente em todas as razões molares ácido: álcool utilizadas, rompendo as ligações lipase-suporte, e consequentemente, causando a lixiviação da Cal B e impossibilitando o reuso da enzima. A síntese do éster butirato de benzila atingiu conversões acima de 80 % na configuração batelada considerando a menor razão molar (1:1) de substratos, mas os ensaios de reuso da enzima mostraram que houve uma perda acentuada da atividade da enzima após o primeiro ciclo de uso. A configuração batelada alimentada se mostrou eficiente para superar os problemas de inibição do ácido butírico e mesmo utilizando uma razão molar de substratos 1:1 a enzima garantiu a conversão máxima (~ 80 %) nos três reciclos testados. Um aumento de volume foi realizado e a elevada conversão foi mantida viabilizando a síntese do éster via enzimática na ausência de solventes. A síntese do éster benzoato de benzila foi conduzida utilizando o ácido benzoico e o anidrido benzoico como doadores acila para as reações de esterificação e acilação, respectivamente. No entanto, o ácido benzoico é um sólido de difícil solubilização e mesmo utilizando diferentes solventes a reação de esterificação não ocorreu. Por outro lado, a reação de acilação se mostrou eficiente na conversão do anidrido benzoico e produção do éster benzoato de benzila garantindo elevadas conversões mesmo na ausência de solventes e considerando apenas um excesso de álcool benzílico. Diferentes configurações de reatores, condições de reação e métodos de agitação foram testados afim de viabilizar a síntese do éster via biocatálise e a configuração em modo batelada foi a mais viável alcançando conversão máxima de 91 % em 6 h considerando uma razão molar ácido: álcool de 1:3. Embora alguns testes ainda sejam necessários para melhorar a performance do biocatalisador na síntese do propionato de benzila via biocatálise, os resultados indicam que as enzimas Novozym 435 e Lipozyme TL IM são biocatalisadores promissores para a síntese dos ésteres butirato/propionato de benzila e benzoato de benzila, respectivamente, com possível ampliação de escala.Abstract: This work aimed the synthesis of aromatic esters benzyl propionate, benzyl butyrate and benzyl benzoate mediated by immobilized enzymes as biocatalysts. The Novozym 435 showed the best performance for the benzyl propionate and benzyl butyrate synthesis in free-solvent system while the Lipozyme TL IM showed the best performance in the benzyl benzoate synthesis. A 2² experimental design was employed to maximize the conversion of both benzyl propionate and butyrate using acid and alcohol as substrates for the esterification. The benzyl propionate synthesis in batch reactor reached a conversion of 44 % and the fed-batch synthesis at same conditions (substrates molar ratio 1:1) reached 90 % of conversion, indicating the acid controlled fed during the first hours of reaction decreased its inhibition effects. Moreover, the optical micrographs of the Novozym 435 support showed the propionic acid acted as a lipase detergent in all substrates molar ratio tested, breaking the lipase-support bonds and, consequently, leaching out the Cal B from the support, making impossible the enzyme recycle. The benzyl butyrate synthesis reached conversions above 80 % in batch configuration considering the lower substrates molar ratio (1:1). However, the enzyme recycle assay showed a sharp decrease in the enzyme activity right after the first cycle of use. The fed-batch configuration showed to be efficient to overcome the butyric acid inhibition effects and the enzyme performance was maintained even at a substrates molar ratio of 1:1, reaching 80 % of conversion in the three recycles tested. The increase in the reaction volume showed a great ester conversion, which makes feasible the benzyl butyrate synthesis mediated by enzymes in the absence of organic solvents and substrate excess. The benzyl benzoate synthesis was conducted using the benzoic acid and benzoic anhydride as acyl donors to the esterification and acylation reactions, respectively. However, the benzoic acid is a solid of difficult solubilization and even using different solvents the esterification did not occur. On the other hand, the acylation showed to be very efficient in the benzoic anhydride conversion and occurred successfully in the absence of solvents, considering only an excess of benzyl alcohol. Different reactor configuration, reaction conditions, and agitation methods were tested in order to feasible the benzyl benzoate via biocatalysis and the batch configuration reached 91 % of conversion after 6 h in a molar ratio of 1:3. Although some tests are still needed to improve the biocatalyst performance in the benzyl propionate synthesis, the present results indicated the enzymes Novozym 435 and Lipozyme TL IM are promising biocatalysts for the benzyl propionate, butyrate and benzoate synthesis, respectively, with possible scale-up
Evaluation of biocompatibility of the membrane of cellulose acetate in dogs with acute renal failure undergoing hemodialysis
ABSTRACT. Meneses A.M.C., Saito M.E., Moraes C.C.G., Souza N.F., Bastos R.K.G., Luz M.A., Seixas L.S., Melchert A. & Caramori J.C.T. [Evaluation of biocompatibility of the membrane of cellulose acetate in dogs with acute renal failure undergoing hemodialysis.] Avaliação da biocompatibilidade da membrana de acetato de celulose em cães com insuficiência renal aguda submetidos à hemodiálise. Revista Brasileira de Medicina Veterinária, 36(4):362-366, 2014. Instituto da saúde e Produção Animal na Amazônia, Universidade Federal Rural da Amazônia, Avenida Presidente Tancredo Neves, 2501, Montese, Belém, PA 66077-530, Brasil. E-mail: [email protected] In order to evaluate the biocompatibility of the membrane of cellulose acetate in dogs with acute renal failure (ARF), undergoing hemodialysis, were used two groups, one consisting of eight normal dogs and the other by eight dogs with ARF induced by gentamicin. Each animal underwent five hemodialysis sessions, with intervals of 24 hours between each one. A significant reduction in urea and creatinine, whereas the other biochemical values were not different between groups, as well as blood pressure, red cell count, white blood cell count and activated clotting time. High levels of TNF-α was found in sick animals, with no detection of this cytokine in normal animals
Mercury exposure in Munduruku indigenous communities from Brazilian Amazon: methodological background and an overview of the principal results
This research was funded by the Vice-Presidency of Environment, Care and Health Promotion (VPPAS) of Fundação Oswaldo Cruz (Fiocruz) through Decentralized Execution of Resources
Document No. 175/2018, Process: 25000.209221/2018-18, signed between the Fiocruz and the Special
Department for Indigenous Health, both under the Ministry of Health. The non-governmental
organization WWF-Brazil offered financial support to disseminate the results of the research.Fundação Oswaldo Cruz. Escola Nacional de Saúde Pública. Departamento de Endemias Samuel Pessoa. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Escola Nacional de Saúde Pública. Centro de Referência Professor Hélio Fraga. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Escola Politécnica de Saúde Joaquim Venâncio. Laboratório de Educação Profissional em Vigilância em Saúde. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Escola Nacional de Saúde Pública. Departamento de Endemias Samuel Pessoa. Rio de Janeiro, RJ, Brazil.Universidade Federal do Rio de Janeiro. Faculdade de Medicina. Instituto de Pediatria e Puericultura Martagão Gesteira. Rio de Janeiro, RJ, Brazil.Universidade Federal do Rio de Janeiro. Instituto de Estudos em Saúde Coletiva. Rio de Janeiro, RJ, Brazil.Imperial College London. Faculty of Medicine. Medical School Building. St Mary’s Hospital. Norfolk Place, London, UK.Universidade de São Paulo. Faculdade de Medicina. Hospital das Clínicas. Centro de Dor, Departamento de Neurologia. São Paulo, SP, Brazil.Universidade de São Paulo. Faculdade de Medicina. Hospital das Clínicas. Centro de Dor, Departamento de Neurologia. São Paulo, SP, Brazil.Universidade de São Paulo. Instituto de Psicologia. Programa de Pós-Graduação em Psicologia Clínica. São Paulo, SP, Brazil.Centro Universitário Estadual da Zona Oeste. Laboratório de Pesquisa de Ciências Farmacêuticas. Rio de Janeiro, RJ, Brazil.Universidade Federal do Oeste do Pará - Unidade Tapajós. Programa de Pós-Graduação em Ciências da Saúde. Santarém, PA, Brazil.Universidade Federal do Oeste do Pará. Programa de Pós-Graduação em Biociências. Santarém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Secretaria Especial de Saúde Indígena Tapajós. Distrito Sanitário Especial Indígena Rio Tapajós. Itaituba, PA, Brazil.Fundação Oswaldo Cruz. Escola Nacional de Saúde Pública. Departamento de Endemias Samuel Pessoa. Rio de Janeiro, RJ, Brazil.The Amazonian indigenous peoples depend on natural resources to live, but human activities’ growing impacts threaten their health and livelihoods. Our objectives were to present the principal results of an integrated and multidisciplinary analysis of the health parameters and assess the mercury (Hg) exposure levels in indigenous populations in the Brazilian Amazon. We carried out a cross-sectional study based on a census of three Munduruku indigenous villages (Sawré Muybu, Poxo Muybu, and Sawré Aboy), located in the Sawré Muybu Indigenous Land, between 29 October and 9 November 2019. The investigation included: (i) sociodemographic characterization of the participants; (ii) health assessment; (iii) genetic polymorphism analysis; (iv) hair mercury determination; and (v) fish mercury determination. We used the logistic regression model with conditional Prevalence Ratio (PR), with the respective 95% confidence intervals (CI95%) to explore factors associated with mercury exposure levels ≥6.0 µg/g. A total of 200 participants were interviewed. Mercury levels (197 hair samples) ranged from 1.4 to 23.9 μg/g, with significant differences between the villages (Kruskal–Wallis test: 19.9; p-value < 0.001). On average, the general prevalence of Hg exposure ≥ 6.0 µg/g was 57.9%. For participants ≥12 years old, the Hg exposure ≥6.0 µg/g showed associated with no regular income (PR: 1.3; CI95%: 1.0–1.8), high blood pressure (PR: 1.6; CI95%: 1.3–2.1) and was more prominent in Sawré Aboy village (PR: 1.8; CI95%: 1.3–2.3). For women of childbearing age, the Hg exposure ≥6.0 µg/g was associated with high blood pressure (PR: 1.9; CI95%: 1.2–2.3), with pregnancy (PR: 1.5; CI95%: 1.0–2.1) and was more prominent among residents in Poxo Muybu (PR: 1.9; CI95%: 1.0–3.4) and Sawré Aboy (PR: 2.5; CI95%: 1.4–4.4) villages. Our findings suggest that chronic mercury exposure causes harmful effects to the studied indigenous communities, especially considering vulnerable groups of the population, such as women of childbearing age. Lastly, we propose to stop the illegal mining in these areas and develop a risk management plan that aims to ensure the health, livelihoods, and human rights of the indigenous people from Amazon Basin