Memarizadeh Nargess, Ghadamyari Mohammad, Adeli Mohsen, Talebi Khalil
Department of Plant Protection, Faculty of Agricultural sciences, University of Guilan, Rasht, Iran.
Department of Chemistry, Faculty of Science, University of Lorestan, Khoramabad, Iran.
Ecotoxicol Environ Saf. 2014 Sep;107:77-83. doi: 10.1016/j.ecoenv.2014.05.009. Epub 2014 Jun 4.
In this work, nano-imidacloprid was prepared by direct encapsulation with ABA triblock linear dendritic copolymers composed of poly(citric acid) (PCA) as A block and poly(ethylene glycol) (PEG) as B block. Nanocapsules of imidacloprid were characterized using spectroscopy, microscopy and thermal analysis. The encapsulation process was performed by self-assembly of PCA-PEG-PCA in the presence of imidacloprid in different solvents. Comparison of the TEM images of nano-imidacloprid prepared in ethanol and water showed that, during the first day, self-assemblies appeared as small particles with an average size of 10-20nm. Depending upon the type of solvent, the time and concentration, morphology and size of the nano-imidacloprid varied from fiber-like to globular to tubular from 10nm to several mm in size. Higher loading capacity and slower release rate of imidacloprid from nano-imidacloprid at optimum pH of Glyphodes pyloalis׳s gut (pH=10) compared to neutral pH confirmed the selective and controllable action of nano-imidacloprid. Results of bioassays on the model insect showed that by using the nanoform of imidacloprid, essential dosage of pesticide and environmental risk decreased significantly and indicated good performance for this formulation.
在本研究中，通过用由聚柠檬酸（PCA）作为A嵌段和聚乙二醇（PEG）作为B嵌段组成的ABA三嵌段线性树枝状共聚物直接包封制备了纳米吡虫啉。使用光谱学、显微镜和热分析对吡虫啉纳米胶囊进行了表征。包封过程是在不同溶剂中，在吡虫啉存在下通过PCA-PEG-PCA的自组装进行的。对在乙醇和水中制备的纳米吡虫啉的透射电子显微镜图像的比较表明，在第一天，自组装体呈现为平均尺寸为10-20nm的小颗粒。根据溶剂类型、时间和浓度的不同，纳米吡虫啉的形态和尺寸从纤维状到球状再到管状，大小从10nm到几毫米不等。与中性pH相比，在棉铃虫肠道的最佳pH值（pH = 10）下，纳米吡虫啉中吡虫啉的负载量更高且释放速率更慢，这证实了纳米吡虫啉的选择性和可控作用。对模型昆虫的生物测定结果表明，通过使用纳米形式的吡虫啉，农药的基本用量和环境风险显著降低，表明该制剂性能良好。
