Nanotecnologia e aquicultura: desenvolvimento de sistemas para controle de doenças baseados em nanopartículas de zeína contendo eugenol e óleo essencial de alho
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Data
2017-07-07
Autores
Sibaja Luis, Angélica Irasema [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A ocorrência de doenças tem ocasionado perdas severas na indústria aquícola. Em virtude do mau uso de produtos químicos no controle e prevenção de doenças em peixes, fica cada vez mais evidente que podem acarretar problemas de contaminação ambiental e riscos à saúde humana. Tem-se buscado novas técnicas de controle alternativo de doenças, como é o caso do emprego de óleos essenciais e extratos vegetais. O eugenol e o óleo de alho são antimicrobianos e antifúngicos naturais, ricos em compostos fenólicos. Entretanto, a eficácia depende da sua disponibilidade e preservação, portanto tem-se buscado alternativas capazes de aumentar sua eficácia, reduzir a volatilização e retardar a taxa de degradação no meio ambiente. Nesse sentido, novos procedimentos estão sendo conduzidos a fim de obter formulações mais eficazes. Polímeros e proteínas estão sendo estudados uma vez que possuem a capacidade de encapsular ativos. A zeína, principal proteína do milho, apresenta características de solubilidade e biocompatibilidade aos seres vivos, tornando a proteína adequada para a desenvolvimento de sistemas carreadores para encapsular ativos, tais como os óleos essenciais. Assim, objetivo deste trabalho foi o desenvolvimento e caracterização de sistemas carreadores a partir de nanopartículas de zeína para encapsulamento de eugenol e óleo essencial de alho. As formulações apresentaram eficiência de encapsulação superior a 85% para ambos os óleos. As nanopartículas de zeína preparadas neste estudo apresentaram um tamanho médio compreendido entre 200 e 300 nm, um índice de polidispersão de 0,2 a 0,3 e potencial zeta de -31 a -27 Mv, para as nanopartículas contendo eugenol e oleo de alho, respectivamente. Sendo que as formulações se mantiveram estáveis por um período de 30 dias, e análises de infravermelho e calorimetria exploratória diferencial demostraram a interação dos ativos com a matriz proteica de zeína. Através do ensaio de cinética de liberação do eugenol observou-se que a liberação deste das nanopartículas ocorre através do transporte anômalo. Os ensaios de disco de difusão realizados para as bactérias Aeromonas hydrophila, Edwardsiella tarda e Streptococcus inae, mostraram que a formulações foram tão eficazes quanto o antibiótico comercial. Os resultados abrem novas perspectivas para a utilização de formulações baseadas em compostos naturais para o controle de doenças em peixes.
The occurrence of diseases has caused severe losses in the aquaculture industry at any stage. Due to the misuse of chemicals in the control and prevention of fish diseases, it is increasingly evident that they can lead to problems of environmental contamination and risks to human health. It has been tried to obtain new techniques of alternative control of diseases, as it is the case of the use of essential oils and vegetal extracts. Eugenol and garlic oil are antimicrobial and natural antifungals, rich in phenolic compounds. However, the efficacy of these compounds depends on their availability and preservation, therefore we have looked for alternatives capable of increasing their effectiveness, reduce the volatilization and delay the rate of degradation in the environment. In this sense, new procedures are being conducted in order to obtain more effective formulations. Polymers and proteins are being studied due to encapsulation capacity, zein, the main maize protein, has characteristics of solubility and biocompatibility. These characteristics make zein a suitable protein for the development of carrier systems to encapsulate active (essential oils). The objective of this work was the development and characterization of carrier systems from zein nanoparticles for encapsulation of eugenol and essential oil of garlic. The formulations showed encapsulation efficiency higher than 85% for both oils. The zein nanoparticles prepared in this study had an average size of 200-300 nm, a polydispersity index of 0.2 to 0.3 and a zeta potential of -31 to -27 mV. The formulations remained stable for a period of 30 days. Infrared (FTIR) and differential calorimetry (DSC) analyzes demonstrated the interaction of the active compounds with the zein protein matrix. Through the release assays it was observed that the release of eugenol by nanoparticles occurs through anomalous transport. The diffusion disc assays performed for the bactéria Aeromonas hydrophila, Edwardsiella tarda and Streptococcus inae showed that the formulations were as effective as the standard antibiotic. The results open new perspectives for their use of formulations based on natural compounds for the control of fish diseases.
The occurrence of diseases has caused severe losses in the aquaculture industry at any stage. Due to the misuse of chemicals in the control and prevention of fish diseases, it is increasingly evident that they can lead to problems of environmental contamination and risks to human health. It has been tried to obtain new techniques of alternative control of diseases, as it is the case of the use of essential oils and vegetal extracts. Eugenol and garlic oil are antimicrobial and natural antifungals, rich in phenolic compounds. However, the efficacy of these compounds depends on their availability and preservation, therefore we have looked for alternatives capable of increasing their effectiveness, reduce the volatilization and delay the rate of degradation in the environment. In this sense, new procedures are being conducted in order to obtain more effective formulations. Polymers and proteins are being studied due to encapsulation capacity, zein, the main maize protein, has characteristics of solubility and biocompatibility. These characteristics make zein a suitable protein for the development of carrier systems to encapsulate active (essential oils). The objective of this work was the development and characterization of carrier systems from zein nanoparticles for encapsulation of eugenol and essential oil of garlic. The formulations showed encapsulation efficiency higher than 85% for both oils. The zein nanoparticles prepared in this study had an average size of 200-300 nm, a polydispersity index of 0.2 to 0.3 and a zeta potential of -31 to -27 mV. The formulations remained stable for a period of 30 days. Infrared (FTIR) and differential calorimetry (DSC) analyzes demonstrated the interaction of the active compounds with the zein protein matrix. Through the release assays it was observed that the release of eugenol by nanoparticles occurs through anomalous transport. The diffusion disc assays performed for the bactéria Aeromonas hydrophila, Edwardsiella tarda and Streptococcus inae showed that the formulations were as effective as the standard antibiotic. The results open new perspectives for their use of formulations based on natural compounds for the control of fish diseases.
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Palavras-chave
Nanopartículas, Zeína, Eugenol, Óleo de alho, Aquicultura