Advances in cyclodextrin-based stimuli-responsive controlled-release nanopesticide systems

Developing efficient, low-toxicity, and environmentally friendly pesticides is critical to ensure food and ecological security. Controlled-release nanopesticides can precisely regulate the release of pesticide, improve the pesticide utilization rate, and reduce environmental pollution and toxicity to non-target organisms, becoming a research hotspot and an important development direction in the field of pesticides. Cyclodextrins, a class of natural macrocyclic molecules, show tremendous potential in the development of stimuli-responsive controlled-release nanopesticide systems due to their unique hydrophobic cavity structure, excellent biocompatibility, and abundant surface-modifiable hydroxyl groups. This review highlights two core design strategies for cyclodextrin-based intelligent carriers, namely the "host-guest switch" strategy based on host-guest interactions and the "backbone-responsive" strategy based on backbone modification, and summarizes the applications of these carriers in stimuli-responsive nanopesticide systems from three aspects: chemical stimuli (pH, enzymes, redox), physical stimuli (light, temperature), and multiple stimuli. Furthermore, the future research directions and existing challenges are discussed. This review is expected to serve as a theoretical reference and practical guidance for the design, synthesis, performance optimization, and industrial application of cyclodextrin-based intelligent pesticides.