A pH‐responsive chitosan‐based nanopesticide for controlled matrine delivery and visualization of pine wood nematode

BACKGROUND Pine wilt disease, caused by the pine wood nematode, causes devastating damage to forest ecosystems worldwide. Conventional chemical control methods have resulted in excessive pesticide use owing to low utilization efficiency, causing significant environmental risks. This study aims to develop a novel nanopesticide (NP) for efficient and sustainable control of pine wood nematode (PWN). RESULTS In this research, a matrine‐loaded NP ( MAT @ CS / CMCS NPs ) was fabricated through ionic cross‐linking of chitosan and carboxymethyl chitosan. The particle size and polydispersity index of this formulation were 213.3 ± 1.3 nm and 0.154 ± 0.009, respectively. Using fluorescein isothiocyanate as a fluorescent probe, the transport of CS / CMCS nanoparticles within pine trees and the uptake by PWN were visually tracked. In vitro release experiments demonstrated that MAT @ CS / CMCS NPs had adjustable controlled release properties and the release rate was higher under acidic conditions. Biosafety assays demonstrated that MAT @ CS / CMCS NPs were safe for HepG ‐2 cells. The results of transcriptome analysis suggested that the higher insecticidal activity of MAT @ CS / CMCS NPs compared to matrine led to the production of more differentially expressed genes after their treatment of PWN, involving increasingly complex biological processes. CONCLUSION This study successfully combines nanocarrier technology with botanical pesticides to develop an effective and environmentally friendly pH ‐responsive NP, providing a novel and sustainable strategy for the control of PWN.