POLYURETHANE MICROPARTICLES INCORPORATED WITH PIPERINE FOR LARVICIDAL ACTION AGAINST Aedes Aegypti

Polymeric nanoparticles incorporated with natural actives, acting as insecticides, have emerged as promising materials for the control of vectors of disease-causing pathogens such as dengue and chikungunya that cause thousands of deaths annually1,2. To evaluate the larvicidal activity of microparticles of a new polyurethane (PU), bioassays were carried out with the larvae of the Aedes aegypti mosquitoes, considered the main vector in Brazil. The PU was prepared from the polycondensation reaction between polycaprolactone-triol and 1,6-hexamethylene diisocyanate at 55 °C for 6 h, pure and loaded with piperine. Pure PU particles had an average particle size of 280.37 nm, a dispersion index of 0.430 and a zeta potential of 3.72 mV. The piperine-loaded PU particles showed mean particle size values of 1,395.78 nm, dispersion index of 0.072 and zeta potential of -27.11 mV, and despite the increase in particles, an improvement in the stability of the system was observed. Larvae mortality was analyzed after 24 h and 48 h of exposure in three different dilutions of the polymeric particles (0.12 g.L-1, 0.34 g.L-1 e 0.58 g.L-1). Larval mortality was 10.67%, 16% and 44% after 48 h of exposure, respectively. As expected, increasing particle concentration increases larval mortality. Therefore, the system based on PU microparticles can be a promising alternative for the incorporation of active insecticides used in the control of vector mosquitoes.