Bio-based clothianidin-loaded solid dispersion using composite carriers to improve efficacy and reduce environmental toxicity

Construction and biological effects of a redox-enzyme dual-responsive lufenuron nano-controlled release formulation

BACKGROUND

Pesticide formulations based on nanotechnology can effectively improve the efficiency of pesticide utilization and reduce pesticide residues in the environment. In this study, mesoporous silica nanoparticles containing disulfide bonds were synthesized by the sol-gel method, carboxylated and adsorbed with lufenuron, and grafted with cellulose to obtain a lufenuron-loaded nano-controlled release formulation (Luf@MSNs-ss-cellulose).

RESULTS

The structure and properties of Luf@MSNs-ss-cellulose were characterized. The results showed that Luf@MSNs-ss-cellulose exhibits a regular spherical shape with 12.41% pesticide loading. The highest cumulative release rate (73.46%) of this pesticide-loaded nanoparticle was observed at 7 days in the environment of glutathione and cellulase, which shows redox-enzyme dual-responsive performance. As a result of cellulose grafting, Luf@MSNs-ss-cellulose had a small contact angle and high adhesion work on corn leaves, indicating good wetting and adhesion properties. After 14 days of spraying with 20 mg L-1 formulations in the long-term control efficacy experiment, the mortality of Luf@MSNs-ss-cellulose against Ostrinia furnacalis larvae (56.67%) was significantly higher than that of commercial Luf@EW (36.67%). Luf@MSNs-ss-cellulose is safer for earthworms and L02 cells.

CONCLUSION

The nano-controlled release formulation obtained in this study achieved intelligent pesticide delivery in time and space under the environmental stimulation of glutathione and cellulase, providing an effective method for the development of novel pesticide delivery systems. © 2023 Society of Chemical Industry.

A facile one-pot route to fabricate clothianidin-loaded ZIF-8 nanoparticles with biocompatibility and long-term efficacy

BACKGROUND

Neonicotinoids are among the most essential chemical insecticides worldwide because of their high activity against many important pests and wide application. However, their application is limited by their toxicity to honeybees. Therefore, the development of a facile route to fabricate efficient and eco-friendly pesticide formulations is of great significance.

RESULTS

In this study, clothianidin-loaded zeolitic imidazolate framework-8 (CLO@ZIF-8) nanoparticles were fabricated by a facile one-pot route using zinc nitrate as a Zn²⁺ source and characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, energy-dispersive spectrometry and Fourier transform infrared spectroscopy. Based on the pH response of ZIF-8, a 'burst release effect' was observed for CLO@ZIF-8 at pH 3 and 5 within 12 h, in contrast to the slow and sustainable release at pH 8. CLO@ZIF-8 improved the retention ability of the pesticide liquid and remained 70% control efficacy on Nilaparvata lugens after water rinsed of sprayed CLO@ZIF-8. The pH response of CLO@ZIF-8 allowed it to maintain 43% control efficacy against N. lugens after 10 days of application, which was twice the efficacy of clothianidin solution (SCA). Moreover, CLO@ZIF-8 reduced the acute toxicity to honeybees (Apis mellifera) by ≥120-fold compared with SCA.

CONCLUSION

This study provides new insights into the application of ZIF-8 to neonicotinoids and suggests the need for the development of a biocompatible and eco-friendly pesticide formulation. © 2023 Society of Chemical Industry.

Controlled release of dinotefuran with temperature/pH-responsive chitosan-gelatin microspheres to reduce leaching risk during application

Neonicotinoid-based pesticides are extensively used owing to their broad insecticidal spectrum and activity. We developed neonicotinoid dinotefuran (DIN)-loaded chitosan-gelatin microspheres using a spray-drying technology, resulting in a pH- and temperature-responsive controlled-release system. Upon introducing chitosan into the triple-helix structure of gelatin, the physically modified gelatin microspheres became smooth, round, and solid, improving their thermal storage stability. The spray-drying parameters were optimized using three-dimensional surface plots. When scaled up under optimal conditions, the corresponding loading content and encapsulation efficiency were 21.5% and 98.17%, respectively. Compared with commercial dinotefuran granules, our biodegradable composite carriers achieved the immobilization of dinotefuran to reduce pesticide leaching by 5.57-19.89% in soil, improved the soil half-life of DIN, and improved its cumulative absorption by plants. Therefore, the microspheres showed better efficacy against Trialeurodes vaporariorum. Our results confirm that this simple approach can improve the utilization efficiency of neonicotinoids, decrease leaching loss, and promote ecological safety.