Nanodelivery System Alters an Insect Growth Regulator’s Action Mode: From Oral Feeding to Topical Application

Abstract

Insect growth regulators (IGRs) guide animal development through injection, oral feeding, or topical application. Among them, lufenuron is a widely used insect cuticle inhibitor but only shows a gastric toxic effect. Lacking contact toxicity limits the effective utilization when spraying the lufenuron pesticide. To overcome this shortcoming, a nanocarrier (star polycation, SPc)-based transdermal delivery system was applied to improve the penetrability and contact toxicity of lufenuron. The fluoride groups in lufenuron could interact with the tertiary amines in the branch-chain of the SPc through electrostatic interaction to form a lufenuron/SPc complex. The above interaction reduced the particle size of lufenuron from 933 to 70 nm. Interestingly, the contact toxicity of SPc-loaded lufenuron was remarkably improved with effects of higher larval mortality and lower egg hatching rate of the devastating pest fall armyworm. The physiological and molecular toxic mechanism was revealed by RNA-Seq analysis. The SPc-loaded lufenuron apparently down-regulated cuticle-related genes and thus inhibited insect cuticle formation. Such contact toxicity was achieved by the transdermal nanodelivery of lufenuron, which up-regulated endocytosis-related genes for drug uptake. This study is the first successful application of a nanoparticle-mediated transdermal delivery system to explore the contact toxicity of an IGR, which alters the IRG’s action mode from oral feeding to topical application.

Chronic exposure to the star polycation (SPc) nanocarrier in the larval stage adversely impairs life history traits in Drosophila melanogaster

“…We have shown that the nanometerization of various pesticides by SPc results in enhanced toxicity against pests in both laboratory experiments and field tests [ 13 – 21 , 88 , 89 ]. SPc shows great potential as pesticide adjuvant for large-scale application in the crop fields, and our biotoxicity analysis could help to develop guidelines to reduce the environmental and health risks.…”

Calcium nutrition nanoagent rescues tomatoes from mosaic virus disease by accelerating calcium transport and activating antiviral immunity

“…According to the previous interpretation of ITC data ( Ross and Subramanian, 1981 ), the self-assembly of calcium glycinate/SPc complex was through hydrogen bond and Van der Waals force, and this interaction was automatic. The complexation of SPc with exogenous substance can be achieved via different interaction forces, such as electrostatic interaction with thiamethoxam ( Yan et al., 2021a ) and lufenuron ( Zhang et al., 2022b ), hydrogen bond and Van der Waals force with chitosan ( Wang et al., 2021 ) and dinotefuran ( Jiang et al., 2022a ), and hydrophobic association with thiocyclam ( Wang et al., 2022b ). Thus, the application area of SPc is broad for delivering various types of exogenous substances.…”

“…The SPc-based nano-delivery system can reduce the particle size of synthetic/botanical pesticides and increase their water solubility and dispersity ( Yan et al., 2021b ; Yan et al., 2022 ; Wang et al., 2022b ). At the cellular level, the SPc can activate the clathrin-mediated endocytosis for enhanced cellular uptake and promote the endosomal escape for intracellular spreading of exogenous substances ( Wang et al., 2021 ; Ma et al., 2022b ; Yang et al., 2022 ; Zhang et al., 2022b ). In vivo , the SPc can increase plant uptake to improve the bioactivity of various exogenous substances ( Wang et al., 2022b ; Jiang et al., 2022a ; Jiang et al., 2022b ).…”

RNA interference cannot be operated in lepidopteran insect? A nanocarrier breaks bottlenecks at all developmental stages of Spodoptera frugiperda

“…demonstrated that the control e cacy can be improved by co-delivering dsRNA and pesticides, and codelivery of dsCDA1 and lufenuron may achieve a desired control e cacy for fall armyworms (Zhang et al 2022).…”