Spherical and Spindle-Like Abamectin-Loaded Nanoparticles by Flash Nanoprecipitation for Southern Root-Knot Nematode Control: Preparation and Characterization.

Zhinan Fu,Yan Wang,Xuhong Guo,Dianhua Liu,Fang Zhao,Yue Shen,Mingwei Wang,Li Li,Kai Chen,Haixin Cui

doi:10.3390/nano8060449

Abstract

Southern root-knot nematode (Meloidogyne incognita) is a biotrophic parasite, causing enormous loss in global crop production annually. Abamectin (Abm) is a biological and high-efficiency pesticide against Meloidogyne incognita. In this study, a powerful method, flash nanoprecipitation (FNP), was adopted to successfully produce Abm-loaded nanoparticle suspensions with high drug loading capacity (>40%) and encapsulation efficiency (>95%), where amphiphilic block copolymers (BCPs) poly(lactic-co-glycolic acid)-b-poly(ethylene glycol) (PLGA-b-PEG), poly(d,l-lactide)-b-poly(ethylene glycol) (PLA-b-PEG), or poly(caprolactone)-b-poly(ethylene glycol) (PCL-b-PEG) were used as the stabilizer to prevent the nanoparticles from aggregation. The effect of the drug-to-stabilizer feed ratio on the particle stability were investigated. Moreover, the effect of the BCP composition on the morphology of Abm-loaded nanoparticles for controlling Meloidogyne incognita were discussed. Notably, spindle-like nanoparticles were obtained with PCL-b-PEG as the stabilizer and found significantly more efficient (98.4% mortality at 1 ppm particle concentration) than spherical nanoparticles using PLGA-b-PEG or PLA-b-PEG as the stabilizer. This work provides a more rapid and powerful method to prepare stable Abm-loaded nanoparticles with tunable morphologies and improved effectiveness for controlling Meloidogyne incognita.

Highlights

Plant-parasitic nematodes are one of the major agricultural pests worldwide, which have caused in excess of $157 billion in global crops damage annually [1]
Plants are grown in the soil in which Meloidogyne incognita have been controlled through the use of synthetic nematicides, such as fumigant nematicides [4]
Abm-loaded nanoparticles were prepared by flash nanoprecipitation (FNP) method using a four-stream multi-inlet vortex mixer (MIVM) (Figure 1a). 2T.h2.eParmeppahriapthiiolinc obfloAckbmco-pLoolaydmederN(PaLnGopAa-rbt-iPcEleGs, PLA-b-PEG, or PCL-b-PEG; 10k-b-5k) and Abamectin wereAdbismso-lovaedeidn nTaHnFo.pDairftfiecrlenstwderruegp-troe-pstaarbeidlizbeyr FfeNedP rmateiothso(dweuisgihntg) awfeorueru-setrde:a1m:10M, I2V.5M:10(,F7i.g5u:1r0e, 1aan)d

Summary

Introduction

Plant-parasitic nematodes are one of the major agricultural pests worldwide, which have caused in excess of $157 billion in global crops damage annually [1]. One basic and formidable problem of Abm is its low solubility in water In many cases, it is applied in the form of oil in water emulsion [8], which shows limited steady shelf time and binds to organic contents in crops. FNP involves rapid micromixing of organic solutions of the hydrophobic drug and BCP with water (anti-solvent) in a multi-inlet vortex mixer (MIVM) to create high supersaturations of the drug in milliseconds, and rapidly form the hydrophobic core (drug) in the mixed solvent

Materials and Methods

Characterization

Biological Assay

Effect of BCP on Size and Morphology of Abm-Loaded Particles