Amphiphilic Block Copolymer Nanocarriers Co-Loaded with Pesticide and dsRNA for Synergistic Pest Control

Pesticides are essential for safeguarding crop health, yet improving their utilization efficiency remains a pressing challenge. In this study, we developed an amphiphilic block copolymer-based nanocarrier, polycaprolactone-block-poly(2-(dimethylamino)ethyl methacrylate), to codeliver avermectin (AVM) and hemocytin-targeting double-stranded RNA (dshem) for the synergistic control of Myzus persicae. The optimized copolymer, PCL45-b-PDMAEMA64, efficiently coloaded AVM and dshem via hydrogen bonding and van der Waals interactions (for AVM) and electrostatic interactions (for dshem), forming a stable nanocomplex with an average diameter of ∼120 nm. Surface contact angle measurements indicated enhanced wettability and potential for improved cuticle penetration. Bioassays demonstrated synergistic effects, achieving 71.4% aphid mortality under laboratory conditions within 3 days and 92.6% under field conditions within 2 days. Hemocytin, an immune-related gene, was shown to play an important role in modulating aphid susceptibility to chemical insecticides. This polymer-based nanocarrier system offers a promising strategy for enhancing pesticide efficacy while minimizing environmental impact through reduced chemical input.