Nanoparticles from silk fibroin and Amazon oils: Potential larvicidal activity and oviposition deterrence against Aedes aegypti

Abstract

This work reports the preparation of nanoparticles of silk fibroin with esters obtained from the oils of two Amazonian plant species (Carapa guianensis Aublet and Bertholletia excelsa) with excellent physicochemical properties and activity against the larvae of the vector Aedes aegypti. The temporal stability of the nanoparticles was evaluated for 50 days at temperatures of 4 ºC and 32 ºC. The size of the nanoparticle was satisfactory, with sizes ranging from 207 ± 2.3 nm to 540.8 ± 23.8 nm, and PdI values ranging from 0.294 to 0.560, and zeta potential from − 37.9 ± 0.3 mV to − 62.9 ± 0.7 mV. Study of the morphology of nanoparticles, by transmission electron microscopy analysis, clearly showed spherical shapes . The nanoparticles presented slow and controlled release that induced a high mortality rate in the 3rd larval instar of Ae. aegypti, with LC50 of 27.45 μg. mL−1 for FABE-Cg-SF-NPs and LC50 of 21.14 μg.mL−1 for FABE-Be-SF-NPs, after 48 h of exposure. In addition, they were able to inhibit oviposition by Ae. aegypti. However, the nanoparticles did not present significant teratogenic effects on zebrafish embryos up to 72 h post-fertilization. Thus, the formation of nanoparticles by butyl esters in silk fibroin may become an (eco)alternative and effective in the control of Ae. aegypti larvae.