Produção de lipídios especiais por interesterificação enzimática de óleos da Amazônia e influência na atividade biológica

Orientadores: Gabriela Alves Macedo, Ana Paula Badan RibeiroTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de AlimentosResumo: Este trabalho teve como objetivos produzir, caracterizar e avaliar as propriedades antimicrobianas de bases lipídicas interesterificadas produzidas com óleos e gorduras da Amazônia utilizando diferentes lipases. No trabalho foram utilizadas duas misturas de óleo e gordura da Amazônia para a produção das bases lipídicas, sendo a primeira delas composta pelo óleo de buriti e a gordura de murumuru e a segunda composta pelo óleo de patauá e a estearina de palma. As reações de interesterificação foram catalizadas por duas lipases em três sistemas enzimáticos diferentes: lipase comercial Lipozyme TL-IM (Novozymes), lipase do micro-organismo Rhizopus sp. e a mistura de ambas as enzimas (comercial + Rhizopus sp.). Em ambas as misturas, os lipídios produzidos apresentaram diferentes características dependendo da enzima utilizada. Na mistura buriti: murumuru, a lipase de Rhizopus sp., além de ser específica pelas posições sn-1,3 do triacilglicerol, foi específica para o tipo de ácido graxo (insaturado). A lipase comercial foi específica apenas pelo tipo de ácido graxo (insaturado), enquanto que a utilização de ambas as enzimas não apresentou efeito sinérgico nesta mistura, os resultados obtidos foram intermediários aos obtidos com as enzimas individualmente. Na mistura patauá: estearina de palma, a lipase de Rhizopus sp. foi específica para o tipo de ácido graxo (insaturados), enquanto que a lipase comercial não demonstrou específicidade para esta mistura. No sistema catalisado por ambas as enzimas também não foi observado efeito sinérgico; os resultdos obtidos foram similiares aos obtidos com a enzima de Rhizopus sp. Para ambas as misturas, com os três sistemas enzimáticos, houve redução nos triacilglceróis trisaturados e tri-insaturados após as reações, com a formação de bases lipídicas predominantemente mono e di-insaturados. Estes lipídios formados mantiveram a concentração elevada de tocoferóis, carotenos e fenóis, indicando que a reação não influenciou na concentração dos compostos minoritários. Na avaliação antimicrobiana, as misturas antes e após a interesterificação foram emulsificadas, produzindo diferentes respostas. Emulsões produzidas com os lipídios interesterificados apresentaram menor tamanho de partícula e maior potencial antimicrobiano, exibindo efeito bactericida; emulsões produzidas com as misturas não-interesterificadas, apresentaram maior tamanho de partícula e menor potencial antimicrobiano, exibindo efeito bacteriostático. Portanto, as lipases foram capazes de catalisar as reações de interesterificação entre os óleos da Amazônia, indicando o potencial destes catalisadores nestas reações. As frações lipídicas obtidas apresentaram atividade antimicrobiana, o que abre precedentes para que estudos biológicos mais aprofundados sejam realizadosAbstract: This study aimed to produce, characterize and evaluate the antimicrobial properties of interesterified Amazonian oils produced by different lipases. Two blends of Amazonian oils were subjected to enzymatic interesterification: the first one was composed by buriti oil and murumuru fat and the second one was composed by patauá oil and palm stearin. The interesterification reactions were catalyzed by two microbial lipases in three different enzymatic systems: one with a commercial lipase Lipozyme-TL-IM (Novozymes); a second with a lipase from the microorganism Rhizopus sp.; and the third with a mixture of both lipases (commercial and Rhizopus sp.). In both blends, depending on the enzyme used, the lipids produced presented different characteristics. In the buriti: murumuru blend, the lipase from Rhizopus sp. besides being specific for the sn-1,3 positions of triacylglycerol was specific for the type of fatty acids (unsaturated). The commercial lipase was specific only for the type of fatty acids (unsaturated), while the use of both enzymes showed no synergistic effect in this blend; the results were intermediate to those obtained with the individual enzymes. In the patauá: palm stearin blend, the lipase from Rhizopus sp. is specific for the type of fatty acid (unsaturated), while commercial lipase showed no specificity to this blend. In the system with both enzymes no synergistic effect was also observed; the results obtained were similiar to those obtained using only the enzyme from Rhizopus sp. In both blends, with the three enzymatic systems, there was a reduction in the proportions of triacylglycerols of the types trisaturated and tri-unsaturated after the reactions, with the formation of predominantly mono -and di- unsaturated lipids. These lipids produced maintained the high concentration of tocopherols, carotenoids and phenolics, indicating that the reaction did not influence the concentration of minor compounds. In the antimicrobial evaluation, the blends before and after interesterification were emulsified, producing different responses. Emulsions produced with interesterified lipids showed lower droplet size and higher antimicrobial activity (bactericidal effect); emulsions produced with non-interesterified blends showed larger droplet size and lower antimicrobial activity (bacteriostatic effect). Therefore, lipases were able to catalyze the interesterification reactions between Amazonian oils, indicating the potential of these catalysts in these reactions. Lipids obtained showed antimicrobial activity, which encourages more detailed biological studiesDoutoradoCiência de AlimentosDoutora em Ciência de Alimento

Biochemical characterization of cutinase produced in different growth medium by Fusarium oxysporum and evaluation of enantioselective potencial of these enzymes

Orientadores: Gabriela Alves Macedo, Patricia de Oliveira CarvalhoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de AlimentosResumo: A cutinase (E.C. 3.1.1.74) é uma enzima que catalisa a hidrólise de ligações ésteres da cutina. A cutina é um biopolímero insolúvel em água, composto de ácidos graxos com C16 e C18, e que está presente na superfície externa das partes aéreas das plantas. Estudos têm sido realizados com o objetivo de caracterizar bioquimicamente cutinases produzidas por diferentes processos fermentativos, micro-organismos e meios de cultivo. As cutinases têm-se mostrado bastante estáveis em diferentes condições de análise. O conhecimento das condições ótimas de ação desta classe de enzimas, assim como dos fatores que afetam a sua atividade são de extrema importância para se compreender melhor a atuação e as alterações sofridas por estas enzimas em diferentes condições de estocagem e trabalho. Tendo em vista estas observações, o objetivo deste estudo foi caracterizar bioquimicamente e comparar as cutinases produzidas por Fusarium oxysporum em quatro meios de cultivo sólidos distintos, compostos por farelo de trigo, casca de soja, farelo de arroz e torta de pinhão manso. A caracterização de cada uma dessas enzimas mostrou que estas apresentam temperatura ótima entre 30 e 37°C, temperatura de estabilidade de 30°C para as enzimas produzidas em meios com de farelo de trigo e farelo de arroz e 37°C para as enzimas produzidas em meios com casca de soja e torta de pinhão manso. O pH ótimo de ação das quatro enzimas mostrou-se levemente alcalino, sendo igual a 8,0 nas enzimas produzidas em meios com farelo de trigo, casca de soja e farelo de arroz e 9,0 para a enzima produzida em meio com torta de pinhão manso. O pH em que as quatro enzimas foram mais estáveis foi igual a 6,0. As quatro enzimas apresentaram boa afinidade pelo substrato, com valores de constante cinética (km) que variaram de 0,25 a 0,65 mM. A enzima produzida em meio com casca de soja apresentou a maior velocidade máxima (vmax), 7,86 U/mL. A maioria dos sais minerais testados inativaram ou ativaram pouco as enzimas produzidas em meios com farelo de trigo, casca de soja e farelo de arroz, enquanto que a enzima produzida em meio com torta de pinhão manso foi bastante ativada na presença da maioria dos sais minerais. As enzimas de farelo de trigo, casca de soja e torta de pinhão manso apresentaram maior especificidade por ésteres de cadeia carbônica média (p-nitrofenil caprilato), enquanto que a enzima produzida em meio com farelo de arroz apresentou maior especificidade por ésteres de cadeia curta (p-nitrofenil butirato). A enzima produzida em meio com torta de pinhão manso foi bastante ativa na presença de solventes orgânicos, especialmente o hexano. A eletroforese por SDS-PAGE mostrou uma banda de 27-30 kDa nas enzimas produzidas em meios com farelo de trigo, casca de soja e torta de pinhão manso. Em relação as suas propriedades enantiosseletivas, a enzima produzida em meio com casca de soja foi a que apresentou melhor resultado (E=5,9)Abstract: Cutinase (E.C. 3.1.1.74) is an enzyme that catalyzes the hydrolysis of esters bonds in cutin. Cutin is a biopolymer insoluble in water composed of fatty acids C16 and C18 and found in the outside surface of the plants¿ aerial parts. Studies have been conducted with the aim of biochemically characterizing the cutinases produced by different fermentation conditions, microorganisms and growth medium. Cutinases have proved to be very stable in different conditions of analysis. The knowledge of optimum conditions of this class of enzymes, as well as of the factors that affect their activity are very important in order to understand the action of such enzymes and the alterations they go through in different conditions of storage and use. Considering that, the objective of this study is to biochemically characterize and compare cutinases produced by Fusarium oxysporum in four different solid growth medium composed of wheat bran, soy rind, rice bran and Jatropha curcas seed cake. The characterization of each one of these enzymes showed that they present the optimum temperature between 30 and 37°C, stability temperature at 30°C for wheat bran and rice bran and 37°C for soy rind and Jatropha curcas seed cake. The optimum pH of action of the four enzymes was little alkaline: 8.0 for the enzymes produced by wheat bran, soy rind and rice bran and 9.0 for the enzyme produced by Jatropha curcas seed cake. The most stable pH for the four enzymes was 6.0. The four enzymes showed good affinity by the substrate, with values of km ranging from 0.25 to 0.65 mM. The enzyme produced in soy rind showed higher value of vmax 7.86 U/mL. Most of the tested mineral salts inactivated or activated just a little the enzymes produced by wheat bran, soy rind and rice bran, whereas the enzyme produced by Jatropha curcas seed cake was very activated in the presence of most of the mineral salts. The enzymes of wheat bran, soy rind and Jatropha curcas seed cake showed more specificity for mediumlength carbonic chain esters (p-NPC), whereas the enzyme of rice rind showed more specificity for short-length chain esters (p-NPB). The enzyme of Jatropha curcas seed cake was very activated by the presence of organic solvents, especially hexane. The electrophoresis by SDS-PAGE showed a band of 27-30 kDa in the enzymes produced by wheat bran, soy rind and Jatropha curcas seed cake. Regarding enantioselectivity proprieties the enzyme produced in soy rind showed the best result (E= 5.9 )MestradoMestre em Ciência de Alimento

Monetary rewards modulate inhibitory control

The ability to override a dominant response, often referred to as behavioral inhibition, is considered a key element of executive cognition. Poor behavioral inhibition is a defining characteristic of several neurological and psychiatric populations. Recently, there has been increasing interest in the motivational dimension of behavioral inhibition, with some experiments incorporating emotional contingencies in classical inhibitory paradigms such as the Go/NoGo and Stop Signal Tasks (SSTs). Several studies have reported a positive modulatory effect of reward on performance in pathological conditions such as substance abuse, pathological gambling, and Attention Deficit Hyperactive Disorder (ADHD). However, experiments that directly investigate the modulatory effects of reward magnitudes on the performance of inhibitory tasks are scarce and little is known about the finer grained relationship between motivation and inhibitory control. Here we probed the effect of reward magnitude and context on behavioral inhibition with three modified versions of the widely used SST. The pilot study compared inhibition performance during six blocks alternating neutral feedback, low, medium, and high monetary rewards. Study One compared increasing vs. decreasing rewards, with low, high rewards, and neutral feedback; whilst Study Two compared low and high reward magnitudes alone also in an increasing and decreasing reward design. The reward magnitude effect was not demonstrated in the pilot study, probably due to a learning effect induced by practice in this lengthy task. The reward effect per se was weak but the context (order of reward) was clearly suggested in Study One, and was particularly strongly confirmed in study two. In addition, these findings revealed a 'kick start effect' over global performance measures. Specifically, there was a long lasting improvement in performance throughout the task when participants received the highest reward magnitudes at the beginning of the protocol. These results demonstrate a dynamical behavioral inhibition capacity in humans, as illustrated by the reward magnitude modulation and initial reward history effects. © 2014 Herrera, Speranza, Hampshire and Bekinschtein

Antioxidant potential and modulatory effects of restructured lipids from the amazonian palms on liver cells

Enzymatic interesterification is used to manipulate oil and fat in order to obtain improved restructured lipids with desired technological properties. However, with raw materials containing significant amounts of bioactive compounds, the influence of this enzymatic process on the bioactivity of the final product is still not clear. Thus, the aim of this study is to evaluate the antioxidant potential and modulatory effects of two raw materials from the Amazonian area, buriti oil and murumuru fat, before and after lipase interesterification, on human hepatoma cells (HepG2). The results indicate that minor bioactive compounds naturally found in the raw materials and their antioxidant capacity are preserved after enzymatic interesterification, and that the restructured lipids modulate HepG2 endogenous antioxidant enzyme554553561CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2012- -22774-5; 2012-22829-4Sem informaçãoSem informaçã

Expectation of reward differentially modulates executive inhibition

Abstract: Background: Inhibitory control, a key modulatory component of cognition guiding strategy and behaviour, can be affected by diverse contingencies. We explore here the effect of expectation of reward over behavioural adjustment in a Stop Signal Task modulated by reward. We hypothesize that cognitive control is modulated by different expectation of the reward. Methods: Participants were allocated to two groups differing in their degree of knowledge in what to expect from rewards. Expected Specific Reward participants (N = 21) were informed of the different monetary feedbacks they would receive after each successful inhibition. Unexpected Reward participants (N = 24) were only told that they would receive monetary reward after correct inhibitory trials, but not the amounts or differences. Results: Our results confirmed previous observations demonstrating a “kick-start effect” where a high reward feedback at the beginning of the task increases response inhibition. The Expected Specific Reward condition seems also to improve inhibitory control -as measured by the stop signal reaction time (SSRT)-, compared to the Unexpected Reward group. Conclusions: Knowledge of reward magnitudes seems to play a role in cognitive control irrespective of feedback magnitude. The manipulation of reward expectation appears to trigger different strategies for cognitive control, inducing a bottom-up effect of external cues, or a top-down effect given by the anticipation of incoming rewards. This is an early exploration to unearth possible higher order modulators - expectation and motivation- of cognitive control. This approach aims to gain insight into diverse psychopathological conditions related to impulsivity and altered reward systems such as Attention Deficit Hyperactive Disorder (ADHD), personality disorders, substance abuse, pathological gambling and cognitive aspects of Parkinson Disease

Expectation of reward differentially modulates executive inhibition

Background: Inhibitory control, a key modulatory component of cognition guiding strategy and behaviour, can be affected by diverse contingencies. We explore here the effect of expectation of reward over behavioural adjustment in a Stop Signal Task modulated by reward. We hypothesize that cognitive control is modulated by different expectation of the reward. Methods: Participants were allocated to two groups differing in their degree of knowledge in what to expect from rewards. Expected Specific Reward participants (N = 21) were informed of the different monetary feedbacks they would receive after each successful inhibition. Unexpected Reward participants (N = 24) were only told that they would receive monetary reward after correct inhibitory trials, but not the amounts or differences. Results: Our results confirmed previous observations demonstrating a 'kick-start effect' where a high reward feedback at the beginning of the task increases response inhibition. The Expected Specific Reward condition seems also to improve inhibitory control -as measured by the stop signal reaction time (SSRT)-, compared to the Unexpected Reward group. Conclusions: Knowledge of reward magnitudes seems to play a role in cognitive control irrespective of feedback magnitude. The manipulation of reward expectation appears to trigger different strategies for cognitive control, inducing a bottom-up effect of external cues, or a top-down effect given by the anticipation of incoming rewards. This is an early exploration to unearth possible higher order modulators - expectation and motivation- of cognitive control. This approach aims to gain insight into diverse psychopathological conditions related to impulsivity and altered reward systems such as Attention Deficit Hyperactive Disorder (ADHD), personality disorders, substance abuse, pathological gambling and cognitive aspects of Parkinson Disease. © 2019 The Author(s)

Evaluation of Nanostructured Lipid Carriers Produced with Interesterified Buriti Oil

Pozadina istraživanja. Ulje buritija, izolirano iz pulpe amazonskog ploda, bogato je mikroelementima s antioksidativnim svojstvima i velikom biološkom vrijednošću. Nekoliko dostupnih istraživanja pokazuju da bi ovo ulje moglo imati široki spektar primjene, međutim nijedno istraživanje nije se dosad bavilo poboljšanjem njegovih značajki za komercijalnu primjenu. Enzimska interesterifikacija je jedna od dostupnih metoda za poboljšanje svojstava ulja i masti, a rezultati naših nedavnih ispitivanja pokazuju da lipaza specifično djeluje na ulje buritija, pri čemu nastaju strukturirani lipidi bogati oleinskom kiselinom, a istodobno se očuva većina spojeva prisutnih u manjim količinama u ulju. U ovom smo radu, tragajući za dodatnim načinima proširenja primjene sirovog ulja buritija, proučavali ponašanje strukturiranog ulja u nanostrukturiranim lipidnim nosačima. Eksperimentalni pristup. Nanostrukturirani lipidni nosači proizvedeni su iz interesterificiranog ulja buritija, a njhova stabilnost, veličina kapljica, električni naboj, mikrostruktura, polimorfizam i antioksidativno djelovanje procijenjeni su pomoću metoda ORAC (engl. oxygen radical absorbance capacity) i FRAP (engl. ferric reducing antioxidant power). Rezultati i zaključci. Rezultati pokazuju da je interesterifikacijom nastalo više nezasićenih triacilglicerola, a nanostrukturirani lipidni nosači pripremljeni s interesterificiranim uljem buritija imali su manje kapljice od onih dobivenih iz sirovog ulja buritija. Čestice su ostale stabilne tijekom skladištenja, a nanostrukturirani lipidni nosači pokazali su složeni polimorfizam uz prisutnost triju kristalnih oblika. ORAC vrijednost bila je približno 23 % veća u nanolipidnim nosačima sa strukturiranim lipidima nego u nanolipidnim nosačima sa sirovim uljem buritija, a FRAP vrijednost bila je 16 % veća, što potvrđuje utjecaj interesterifikacije na antioksidacijsku aktivnost nanonosača. Može se zaključiti da su nanostrukturirani lipidni nosači pripremljeni s interesterificiranim uljem buritija imali male kapljice, veliku stabilnost i antioksidativni kapacitet, te da se mogu koristiti u prehrambenim proizvodima i biološkim pripravcima. Novina i znanstveni doprinos. Ovo istraživanje pokazuje da je interesterifikacija pozitivno utjecala na fizikalno-kemijska svojstva nanostrukturiranih lipidnih čestica, a nastalo ulje bilo je bogato oleinskom kiselinom, imalo veliku stabilnost i izražen antioksidativni kapacitet. Stoga je zaključeno da postoji interes za daljnju primjenu tih nanočestica kao učinkovitog sustava nosača.Research background. Extracted from the pulp of an Amazonian fruit, buriti oil is rich in micronutrients with antioxidant properties and high biological value. The few studies available indicate that this oil could be used in a wide range of applications; however, there are no studies that work on the improvement of the characteristics of this oil for commercial application. The enzymatic interesterification is one of the tools available to improve the properties of oils and fats and our recent studies have demonstrated that the lipase could specifically act on buriti oil to produce structured lipids rich in oleic acid, while preserving most of the minor compounds present in this oil. Still looking for ways to expand the applicability of this raw oil, in this work, we are interested in studying the behaviour of this structured oil in nanostructured lipid carriers (NLCs). Experimental approach. The NLCs were produced with interesterified buriti oil and the stability, droplet size, electrical charge, microstructure, polymorphism and antioxidant activity of the samples were evaluated by oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) methods. Results and conclusions. The results showed that the interesterification formed more unsaturated triacylglycerols (TAGs), and NLCs prepared with interesterified buriti oil had smaller droplets than NLCs with crude buriti oil. Particles remained stable throughout the storage period and NLCs exhibited complex polymorphism with the presence of three crystalline forms. The ORAC value was approx. 23 % higher in nanolipid carries with structured lipids than in the nanolipid carriers with crude buriti oil, and the FRAP value 16 % higher, demonstrating the influence of interesterification on the antioxidant activity of nanocarriers. Thus, NLCs prepared with interesterified buriti oil had small droplets, high stability and antioxidant capacity, and have a potential for nutritional and biological applications. Novelty and scientific contribution. This research showed that interesterification positively influenced the physicochemical properties of NLCs, producing the oil rich in oleic acid, high stability and antioxidant capacity. Therefore, it may be interesting to use these nanocarriers to obtain efficient carrier systems for future applications

Antioxidant Potential and Modulatory Effects of Restructured Lipids from the Amazonian Palms on Liver Cells

Enzimska interesterifikacija koristi se za obradu ulja i masti radi dobivanja restrukturiranih lipida sa željenim tehnološkim svojstvima. Međutim, s obzirom na to da sirovi materijali sadržavaju velike udjele bioaktivnih tvari, još uvijek je nejasan utjecaj ovakvih enzimskih procesa na biološku aktivnost konačnog produkta. Stoga je svrha ovog istraživanja bila procijeniti antioksidacijski potencijal i modulacijski učinak dvaju sirovih materijala iz područja Amazone (buriti ulja i murumuru masti) na stanice jetre (HepG2), i to prije i nakon procesa interesterifikacije. Istraživanje je pokazalo da su neke bioaktivne komponente sirovih materijala i njihov antioksidacijski učinak očuvani nakon enzimske esterifikacije restrukturiranih lipida, pri čemu dolazi do modulacije HepG2 endogenog antioksidacijskog enzima.Enzymatic interesterification is used to manipulate oil and fat in order to obtain improved restructured lipids with desired technological properties. However, with raw materials containing significant amounts of bioactive compounds, the influence of this enzymatic process on the bioactivity of the final product is still not clear. Thus, the aim of this study is to evaluate the antioxidant potential and modulatory effects of two raw materials from the Amazonian area, buriti oil and murumuru fat, before and after lipase interesterification, on human hepatoma cells (HepG2). The results indicate that minor bioactive compounds naturally found in the raw materials and their antioxidant capacity are preserved after enzymatic interesterification, and that the restructured lipids modulate HepG2 endogenous antioxidant enzyme

PERCEPÇÃO AUDITIVA DA FALA EM USUÁRIOS DE IMPLANTE COCLEAR COM ELETRODOS DESATIVADOS: REVISÃO DE ESCOPO

Objective: This study aimed to identify, synthesize and analyze the scientific knowledge produced on the auditory perception of speech in patients with cochlear implants with deactivated electrodes. Design/Methods: This is a scoping review following the PRISMA recommendations based on the following guiding question: "How is the performance of auditory speech perception in patients with cochlear implants with deactivated electrodes?". Combinations of descriptors were adapted to five electronic databases: PubMed/MEDLINE, Scopus, Embase, Web of Science, and Lilacs, using the following descriptors: cochlear implant, auditory perception, speech perception, implanted electrodes, medical equipment failure, and device failure. Among the 550 studies found, 12 were included in the sample because they met the inclusion criteria. Results: All studies in the sample analyzed cochlear implant users with deactivated electrodes for different purposes. Most of them were found to see how the number of electrodes enabled along the beam interferes with the auditory perception of speech. Conclusion: Although there is no consensus in the literature regarding the repercussions on auditory speech perception in patients with deactivated electrodes, studies have shown that there is a limitation in performance when the number of electrodes is increased beyond ten electrodes, but there is not enough evidence to support the theory that there is a decrease in speech perception in cases of electrode failure.Objetivo: El objetivo de este estudio fue identificar, sintetizar y analizar el conocimiento científico producido sobre la percepción auditiva del habla en pacientes con implantes cocleares con electrodos desactivados. Diseño/Métodos: Se trata de una revisión exploratoria siguiendo las recomendaciones de PRISMA basada en la siguiente pregunta orientadora: "¿Cómo es el rendimiento de la percepción auditiva del habla en pacientes con implantes cocleares con electrodos desactivados?". Se adaptaron combinaciones de descriptores a cinco bases de datos electrónicas: PubMed/MEDLINE, Scopus, Embase, Web of Science y Lilacs, utilizando los siguientes descriptores: implante coclear, percepción auditiva, percepción del habla, electrodos implantados, fallo de equipos médicos y fallo de dispositivos. De los 550 estudios encontrados, 12 fueron incluidos en la muestra por cumplir con los criterios de inclusión. Resultados: Todos los estudios de la muestra analizaron usuarios de implantes cocleares con electrodos desactivados para diferentes propósitos. Se encontró que la mayoría de ellos veían cómo el número de electrodos habilitados a lo largo del haz interfiere con la percepción auditiva del habla. Conclusión: Aunque no existe consenso en la literatura sobre las repercusiones en la percepción auditiva del habla en pacientes con electrodos desactivados, los estudios han demostrado que existe una limitación en el rendimiento cuando el número de electrodos se incrementa más allá de diez electrodos, pero no hay suficiente evidencia para apoyar la teoría de que existe una disminución de la percepción del habla en casos de fallo del electrodo.Este estudo teve como objetivo identificar, sintetizar e analisar o conhecimento científico produzido sobre a percepção auditiva da fala de pacientes usuários de Implante Coclear com eletrodos desativados. Desenho/Métodos: Trata-se de uma revisão de escopo seguindo as recomendações PRISMA realizada com base na seguinte pergunta norteadora: “Como é o desempenho da percepção auditiva da fala de pacientes usuários de Implante Coclear com eletrodos desativados?”. Combinações de descritores foram adaptadas para cinco bases de dados eletrônicas: PubMed/MEDLINE, Scopus, Embase, Web of Science e Lilacs, por meio dos descritores: implante coclear, percepção auditiva, percepção da fala, eletrodos implantados, falha de equipamentos médicos e falha de dispositivos. Entre os 550 estudos encontrados, 12 compuseram a amostra por responderem aos critérios de inclusão. Resultados: Todos estudos da amostra analisaram os usuários de Implante Coclear com eletrodos desativados com propósitos diferentes. Em sua maioria, foi verificado como o número de eletrodos habilitados ao longo do feixe interfere na percepção auditiva da fala. Conclusão: Embora não haja consenso na literatura quanto às repercussões na percepção auditiva da fala em pacientes com eletrodos desativados, estudos retrataram que ocorre uma limitação no desempenho quando o número de eletrodos é aumentado além de dez eletrodos, mas não há evidência suficiente que embasa a teoria de que há diminuição da percepção da fala nos casos de falha do eletrodo.Objetivo: Este estudo teve como objetivo identificar, sintetizar e analisar o conhecimento científico produzido sobre a percepção auditiva da fala de pacientes usuários de Implante Coclear com eletrodos desativados. Desenho/Métodos: Trata-se de uma revisão de escopo seguindo as recomendações PRISMA realizada com base na seguinte pergunta norteadora: “Como é o desempenho da percepção auditiva da fala de pacientes usuários de Implante Coclear com eletrodos desativados?”. Combinações de descritores foram adaptadas para cinco bases de dados eletrônicas: PubMed/MEDLINE, Scopus, Embase, Web of Science e Lilacs, por meio dos descritores: implante coclear, percepção auditiva, percepção da fala, eletrodos implantados, falha de equipamentos médicos e falha de dispositivos. Entre os 550 estudos encontrados, 12 compuseram a amostra por responderem aos critérios de inclusão. Resultados: Todos estudos da amostra analisaram os usuários de Implante Coclear com eletrodos desativados com propósitos diferentes. Em sua maioria, foi verificado como o número de eletrodos habilitados ao longo do feixe interfere na percepção auditiva da fala. Conclusão: Embora não haja consenso na literatura quanto às repercussões na percepção auditiva da fala em pacientes com eletrodos desativados, estudos retrataram que ocorre uma limitação no desempenho quando o número de eletrodos é aumentado além de dez eletrodos, mas não há evidência suficiente que embasa a teoria de que há diminuição da percepção da fala nos casos de falha do eletrodo