Sustainable DMSNs nano-biopesticide platform built by a “one-pot” method focusing on injury-free drug demonstration of pine wood nematodes

Abstract

Pine wilt disease (PWD) is an infestation caused by pine wood nematodes (PWN, Bursaphelenchus xylophilus), and has caused significant disruption to forest ecosystems worldwide. Trunk injection is effective in controlling PWD, but the long-term use of abamectin (AVM) and other drugs in large quantities has caused resistance problems, and the annual trunk injections have caused some damage to the trunks themselves. In order to reduce drug resistance and damage to the tree trunks, in this study, dendritic mesoporous silica nanoparticles (DMSNs) were prepared by using a “one-pot” method, which is the easiest to industrialise, and AVM@DMSNs nano-pesticides with a uniform particle size, high loading efficiency (80.2%) and sustained release were prepared by physical adsorption. And cellular uptake and toxicity experiments were carried out on sf9 cells, and the results showed that the nano DMSNs could be enriched on sf9 cells and had good inhibition of cellular activity. The lethality of the nano-pesticides AVM@DMSNs and AVM on PWN was investigated using the insect dip method. The results showed that the corrected mortality rate of AVM@DMSNs was significantly higher than that of free AVM within 72 h. In addition, AVM@DMSNs compounded with a plant essential oil bark penetrant could be applied locally outside the bark and penetrate the drug into the tree to achieve the purpose of injury-free drug delivery, which could effectively reduce the damage of perforation injection on the tree and provide a new way for the control of forest pests.