Development of an environmentally friendly formulation of silk fibroin associated with fatty acid from Astrocaryum murumuru Mart. fat, effective against larvae of the Aedes aegypti vector

The Aedes aegypti mosquito is a vector of several diseases, such as dengue, malaria and the Zika virus. Synthetic insecticides such as chlorpyrifos and chlorothalonil have been used for plague control, despite causing damage to the environment and to humans. It is therefore important to study natural active compounds with a low environmental impact. The present paper developed an environmentally friendly formulation of silk fibroin (SF) associated with fatty acid esters [ethyl (FAEE-SF), propyl (FAPE-SF) and butyl (FABE-SF)] from Astrocaryum murumuru Mart. fat, which was effective against Aedes aegypti 3th instar larvae. The FABE-SF nanoemulsion induced a higher mortality rate in the larvae of the A. aegypti after 48 h (LC50 = 18.92 µg / mL). The stabilities of the nanoemulsions were monitored for 21 days, and FABE-SF exhibited greater stability throughout the monitored period, with average particle, zeta and PDI values of around 217 ± 0.85 nm, -25.6 ± 3.24 mV and 0.338 ± 0.01, respectively. This paper reported the first effective action of fatty acid esters from A. murumuru Mart. associated with silk fibroin against A. aegypti. The FABE-SF solution also had a low hemolytic index, suggesting that treatment may be safe for animal and human use.