Rational design of multi-stimuli-responsive polymeric nanoparticles as a ‘Trojan horse’ for targeted pesticide delivery

Understanding the biological environment is essential for designing materials for drug delivery. Inspired by the microenvironment of insects and their digestive process, we designed and synthesized an amphiphilic block copolymer with a redox, enzyme, and alkaline triple stimuli-responsive for pesticide targeted release. The polymer can be self-assembled into nanoparticles to encapsulate pesticides in water. Avermectin was selected as a model drug to demonstrate the potential of the polymer as a targeted pesticide controlled-release system. The results showed that the polymer nanoparticles loaded with avermectin were stable without stimulus, while the release rate of avermectin from the nanoparticles gradually increased after treatment of stimulus. When these avermectin-loaded nanoparticles are used to kill insects, it is like planting a ‘Trojan horse’ into the worms. The bioactivity experiments confirmed that the avermectin-loaded polymer nanoparticles maintained the toxicity of the pesticidal effect. The biosafety evaluation confirmed that the polymer nanoparticles have good biosafety.