Preparation of enzyme-responsive composite nanocapsules with sodium carboxymethyl cellulose to improve the control effect of root-knot nematode disease

Abstract

Developing an efficient drug delivery system to mitigate the harm caused by root-knot nematodes is crucial. In this study, enzyme-responsive release abamectin nanocapsules (AVB1a NCs) were prepared using 4, 4-diphenylmethane diisocyanate (MDI) and sodium carboxymethyl cellulose as response release factors. The results showed that the average size (D50) of the AVB1a NCs was 352 nm, and the encapsulation efficiency was 92 %. The median lethal concentration (LC50) of AVB1a NCs for Meloidogyne incognita activity was 0.82 mg L−1. Moreover, AVB1a NCs improved the permeability of AVB1a to root-knot nematodes and plant roots and the horizontal and vertical soil mobility. Furthermore, AVB1a NCs greatly reduced the adsorption of AVB1a by the soil compared to AVB1a emulsifiable concentrate (EC), and the effect of the AVB1a NCs on controlling root-knot nematode disease was increased by 36 %. Compared to the AVB1a EC, the pesticide delivery system significantly reduced the acute toxicity to the soil biological earthworms by approximately 16 times that of the AVB1a and had a lower overall impact on the soil microbial communities. This enzyme-responsive pesticide delivery system had a simple preparation method, excellent performance, and high level of safety, and thus has great application potential for plant diseases and insect pests control.