Evaluation of the effect of incorporation of natural active in different types of nanoparticles on Aedes aegypti larvicidal activity (LINNAEUS, 1762)

The present study evaluated the mortality of Ae. aegypti exposed to nanocapsules (NC) and nanoemulsions (NE) incorporated with active piperine. Nanoparticles were prepared by nanoprecipitation method and characterized by Dynamic Light Scattering. Ae. aegypti larvae of late 3rd instar and early 4th instar were exposed to nanoparticles in different concentrations and mortality were verified every 24 hours for IC50 determination. The behavior of larvae submitted to the substances studied were analyzed. And external morphological alterations of larvae controls were also verified. Residual tests were performed to determine the larvicidal effect. NC had diameter of 187.4nm, PDI of 0.197nm and Zeta potential of -31.51mV. NE had diameter of 112nm, PDI of 0.116 and Zeta potential of -11.47mV. LC50 of non-nanoencapsulated piperine was 14.50ppm in 24 hours exposure, 6.05ppm in 48 hours and 5.48ppm in 72 hours. NE presented 22.8ppm (24h), 7.12ppm (48h) and 6.25ppm (72h) LC50. The NC LC50 of 34.8ppm (24h), 12.14ppm (48h) and 8.28ppm (72h). During the bioassays it was possible to observe alterations of Aedes aegypti larvae submitted to different treatments, such as lethargy, lack of mobility and decrease of body size. By the method of nanoprecipitation it was able to produce nanostructured systems, presenting the diameter of particles and Zeta potential suitable for the method. The analyzed substances LC50 presented significant differences. As nanoparticles and a piperine solution, they were considered promising as larvicidal agents. The nanocapsule is a nanoemulsion, in summary, more prolonged, compared to a nonnanoencapsulated Piperin. The larvae exposed to the tested substances presented behavioral differences and external morphology alteration, compared to larvae that were exposed to controlO presente trabalho avaliou a mortalidade de larvas de Ae. aegypti expostas a nanocpásulas (NC) e nanoemulsões (NE) tendo o ativo piperina incorporado. As nanopartículas foram preparadas pelo método de nanoprecipitação e caracterizadas por Espalhamento de Luz Dinâmico. Larvas de Ae. aegypti 3º instar final e 4º instar inicial foram expostas as nanopartículas em diferentes concentrações e avaliação da mortalidade foi feita a cada 24 horas, para determinação das CL50. Foram analisados também o comportamento das larvas submetidas as substâncias estudadas e os efeitos causados na morfologia externa. Foram realizados testes residuais para determinação do tempo de efeito larvicida. A NC apresentou diâmetro de 187,4nm, PDI 0,197nm e potencial Zeta de -31,51mV. A NE apresentou diâmetro de 112nm, PDI de 0,116 e potencial Zeta de -11,47mV. As CL50 da piperina não nanoencapsulada foi de 14,50ppm em 24 horas de exposição, 6,05ppm em 48 horas e 5,48ppm em 72h. A NE apresentou CL50 22,8ppm (24h), 7,12ppm (48h) e 6,25ppm (72h). A NC CL50 de 34,8ppm (24h), 12,14ppm (48h) e 8,28ppm (72h). Durante os bioensaios foi possível observar as alterações nas larvas de Ae. aegypti submetidas aos diferentes tratamentos, tais como letargia, falta de mobilidade e diminuição do tamanho corporal. Pelo método de nanoprecipitação foi possível produzir os sistemas nanoestruturado, apresentando diâmetro de partículas e potencial Zeta adequados pelo método. As CL50 das substâncias estudadas apresentaram diferença significativas. As nanopartículas e a solução piperina, foram consideradas promissoras como agentes larvicidas. A nanocápsula e a nanoemulsão apresentarem efeito residual mais prolongado, comparado com a Piperina não nanoencapsulada. As larvas expostas aos bioensaios contendo piperina apresentaram diferença comportamental e na morfologia externa, das larvas que foram expostas ao control