Lufenuron Dual-Carrier Nanoformulation: Controlled Release and Systemic Translocation viaβ-Cyclodextrin Octadecanoate and Urea-Formaldehyde Resin

Through dual encapsulation of the insecticide lufenuron with β-cyclodextrin octadecanoate and urea-formaldehyde resin, a lufenuron@β-cyclodextrin octadecanoate/urea formaldehyde resin (LF@β-CDs/UF) nanoformulation was prepared. This dual-carrier synergy significantly prolonged the release cycle of lufenuron and enhanced environmental adaptability. Results demonstrated that under 25 °C and pH 7 conditions, its release cycle reached 324 h in 20% methanol-water, representing a 1.5-fold prolongation compared to the single-carrier lufenuron@β-cyclodextrin octadecanoate (LF@β-CDs) nanoformulation, with a pH/temperature-responsive release behavior. The photolysis half-life (t₅₀) was extended by 1.6- and 9.3-fold compared to LF@β-CDs (51 h) and lufenuron (LF) microemulsion (8.9 h), respectively. At a low concentration of 6.25 mg/L, the mortality rate against Spodoptera litura reached 73.33%, significantly outperforming LF@β-CDs (29.33%) and LF microemulsion (5.33%). The LF@β-CDs/UF also substantially prolonged insecticidal duration and enhanced the systemic translocation of lufenuron in plants. Biosafety assessment showed that it significantly reduced ecological toxicity, increasing rice seed germination rates from 40.7% (microemulsion) to 71.3% at 400 mg/L seed-soaking concentration, while elevating the acute toxicity LC₅₀ value in zebrafish by 4.4-fold, demonstrating substantially comparative eco-friendliness compared to conventional formulations. This dual-carrier technology, via structure-function synergy, provides an innovative solution to challenges such as low pesticide utilization efficiency and high environmental risks.