Polymer-based nanoinsecticides: current developments, environmental risks and future challenges. A review

Abstract

Introduction. The rapid development of the nanotechnology industry opens new perspectives for modern crop protection strategies. This review summarizes and discusses the use of polymers as nanocarriers of insecticides. They are expected to ensure a higher level of protection for humans and the environment, while ensuring good efficacy of the active ingredient. Literature. Some of the synthetic polymers (including polyethylene glycol, polylactic acid, polycaprolactone and polyhydroxybutyrate), which are widely used in pharmaceutical or cosmetic areas, can be employed as insecticide carriers. But natural polymers (including chitosan, alginate, cellulose, starch and cyclodextrins) are receiving increasing attention because of their environment-friendly properties. The polymeric materials can be prepared in various types of tridimensional structures, among which nanocapsule, nanosphere, micelle, nanogel and nanofiber are the most common for the delivery of the active ingredient. The environmental risks of polymer-based nanoinsecticides are highlighted, together with the main challenges that must be solved before future marketing. These challenges include the reduction of their production cost and assessment of their performance, especially at the field level. New protocols for characterizing, detecting and quantifying are also urgently required. Conclusions. Polymer-based nanoformulations appear to be promising for target release of active ingredients while reducing excess runoff. In order to facilitate the development of new beneficial products, collaboration among countries around the world is required.

Optimization and Characterization of Essential Oil Nanoemulsions Using Ultrasound for New Ecofriendly Insecticides

“…Generally, it is assumed that the ecotoxicity of bioinsecticides is related to the active ingredient mass concentration. Even though the nanoformulation containing bioinsecticides as an active ingredient must be considered as a different product as it shows novel unique properties, it would require a separate ecotoxicology assessment . Consequently, the ecotoxicology of the NEs was analyzed.…”

Stability Phenomena Associated with the Development of Polymer-Based Nanopesticides

“…The polymeric matrix could be coated with surfactants or other materials that stabilize the formulation. Given the amount of polymer in the nanospheres, they can provide greater protection and a more prolonged release of the active ingredient than nanocapsules [ 2 , 57 ].…”

“…Although the synthesis process of nanospheres is very similar to nanocapsules, the mean particle size, size dispersion, and loading efficiency of the nanospheres depend on the polymers employed [ 57 ]. The size of the nanospheres depends, among other aspects, on the molecular weight of the polymers, observing a larger size with larger polymers (high molecular weight) [ 1 , 60 – 62 ].…”

“…The advantages of polymeric nanoparticles include biocompatibility, biodegradability, the ability to modify and functionalize the surface, incorporation of the active agent without any chemical reactions, and the possibility of modulating the degradation and release of the active agent by a selection of the materials used to prepare the nanoparticles [ 98 ]. However, almost all polymeric nanocarriers are synthesized in the laboratory in small amounts; hence, it is necessary to establish standard procedures for a particular group of pesticides, which could be scaled up commercially [ 57 ].…”

Gel Carriers for Plant Extracts and Synthetic Pesticides in Rodent and Arthropod Pest Control: An Overview

“…Various soft gels and pastes have also been used for some types of traditional insecticide [ 4 , 5 ] and rodenticide formulations [ 6 ]. In recent decades, especially with the advent of advances in encapsulation and nanotechnologies [ 4 , 7 , 8 , 9 ], researchers focused their attention on pesticide gel application to new areas of protection of human resources, health, and environment against harmful and invasive organisms. Pesticide gels are thus beginning to be a complement, or in some cases an important environmentally safer alternative, to traditional pesticide formulations.…”