An organic solvent-free self-assembly strategy for scalable preparation of nanobiopesticides with enhanced insecticidal activity against houseflies

Abstract

The abuse of toxic organic solvents has caused great harm to human health and the environment. Therefore, developing an environmentally friendly nano-based pesticide formulation without using harmful solvents is urgent to improve the efficacy of pesticides and minimize environmental and health risks. Herein, by combining aspartic acid (Asp) with spinosad (SSD) as an attractive building unit, a self-assembly and carrier-minimized strategy was applied to construct a nanobiopesticide (Asp-SSD) simultaneously. To further improve the storage stability of the formulation, the biogenic surfactant alkyl polyglucoside (APG) was subsequently added to afford a more stable and smaller nano-delivery system (Asp-SSD-APG). Bioactivity assays showed that Asp-SSD-APG exhibited good quick-acting performance against Musca domestica in the spray assay, and the insecticidal activities of Asp-SSD and Asp-SSD-APG were better than that of the SSD nano-suspension concentrate (Nano-SC). Compared to CK, Asp-SSD-APG reduced the activity of GST, SOD, and CAT in M. domestica, which contributed to the enhanced insecticidal effect of SSD. The cell viability evaluation in 4T1 cells showed that Asp-SSD-APG posed a low risk to the mammalian cells. This study provides an alternative approach for developing environmentally benign nanobiopesticides with a self-assembly and carrier-minimized strategy, which has the potential to improve the efficacy and safety of pesticides in the public health field.