Sugar-Armored Pesticides: Self-Assembled System for Enhanced Foliar Adhesion and Sustained Delivery of Hydrophobic...

Naturally hydrophobic characteristics of most pesticides seriously affect their effective deposition and bioavailability on susceptible plants, causing inevitable off-target movement and environmental pollution. To solve this problem, we employ supramolecular self-assembly strategies to deliver and remedy such defective pesticides, thereby creating a self-assembled, multifunctional delivery system-PyE28@HP-β-CD, which comprises a high-performance pyridyl ether microbicide (PyE28) complexed with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD). This approach transforms insoluble hexagonal sheet structures (PyE28) into biocompatible sugar-armored spherical assemblies (PyE28@HP-β-CD) with sustained release profiles in aqueous environment, ultimately improving the physicochemical/biological properties and targeted delivery efficiency of hydrophobic pesticides. The advancement concretely manifests as: (i) markedly enhanced foliar deposition via improved wetting coverage and reduced interfacial tension (contact angle decreased by 18°), (ii) effective biofilm disruption (achieving an 81.40% biofilm reduction at 23.3 µg mL^-1) through suppression of extracellular polysaccharide biosynthesis, and (iii) superior bactericidal activity against Xanthomonas pathogens mediated by oxidative damage amplification and redox homeostasis interference. In vivo evaluations demonstrated that PyE28@HP-β-CD at 200 µg mL^-1 effectively suppressed citrus canker and rice bacterial blight by 79.73% and 45.53%, respectively, superior to conventional bactericides by 30.76% and 20.33%. This study presents a supramolecular self-assembly approach to optimize hydrophobic agrochemical delivery, combining sustained release with on-demand precision.