Preparation and characterization of atrazine-loaded biodegradable PLGA nanospheres

Atrazine is the second mostly used herbicide in USA,but low utilization ratio causes severe environmental problem,so controlled release system is highly needed in order to minimize the negative impact on environment.In this paper,a herbicide delivery system,atrazine-loaded poly(lactic-co-glycolic acid)(PLGA)nanoparticles(NPs)were prepared by forming an oilin-water emulsion using the emulsion-solvent evaporation method.By varying the preparation conditions of PLGA-NPs,such as sonication time,surfactant content,solvent fraction,and polymer content,the particle sizes of the PLGA-NPs were well controlled from 204 to 520 nm.The morphology and size distribution of PLGA-NPs were evaluated using dynamic light scattering(DLS)and scanning electron microscopy(SEM).Both the encapsulation efficiency and release profile of the herbicide from the PLGA-NPs were typically evaluated by using 2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine(atrazine,ATZ)as the model.ATZ encapsulation efficiency within the PLGA-NPs was ranged from 31.6 to 50.5%.The release profiles of ATZ-loaded PLGA-NPs exhibited a much slower release rate in comparison with that of pure herbicide.The results demonstrated that the prepared PLGA-NPs had a high encapsulation efficiency and slow release rate,which could be used as a promising herbicide release system in agriculture to diminish the impact on the environment and minimize the potential harm to the farmers.