配位组装型农药微胶囊的对靶递释规律及选择毒性调控机制

It is a highlight in pesticide formulation to clarify the controlled release mechanism of microencapsulation technology. To determine and manage the deposition, distribution and release profiles of pesticide microcapsules on the target surface is one of the most crucial approaches to make full use of pesticide microcapsules and therefore achieve time-dependent and quantitative control for the toxicity of microcapsules to target organisms. In the present study, we attempt to fabricate pyraclostrobin microcapsules with different properties using coordination assembly. Single and mingle coordination complexes would be prepared using metal ions and polyphenols and work as wall materials. Rice plants will be selected as target crop and rice blast will be selected as target organism to determine the affinity, deposition, distribution and retention characteristics of pyraclostrobin microcapsules with different size, composition and membrane thickness. Fluorescence visualization technology and pesticide residue analysis would be combined in the process to improve the management of target delivery and release of microcapsules. The release kinetics and dissipation dynamics of pesticides in different situations would be investigated to clarify the toxicity-selective mechanism of these pyraclostrobin microcapsules among rice blast pathogens and non-target aquatic organisms. This work will provide new clue for the establishment of drug-loaded systems with highly toxic selectivity among target and non-target organisms.

农药微胶囊的缓控释机理是当前剂型研究的热点之一。深入探讨农药微胶囊在靶标生物界面的沉积、分布、释放规律并加以调控，对于充分发挥其控释优势，实现微囊对靶标生物毒力/毒性的定时、定量调控具有重要价值。本项目拟以单一或掺杂型金属-多酚配合物为壁材，利用配位组装技术构建不同特征参数的吡唑醚菌酯微胶囊，并进行系统表征研究。以水稻为靶标作物，以稻瘟病为防治对象，通过荧光可视化手段结合农药残留分析技术，构建吡唑醚菌酯微胶囊的尺度、囊壁材料组成、囊壁厚度等特征参数与其在靶标作物界面的亲和、沉积、分布、存留规律的相关性模型，并剖析其内在关联机制，以优化对靶传递效率；通过不同环境中的释放动力学及消解动力学研究，探明金属-多酚配位化合物载药微胶囊在提高稻瘟病防效和降低对水生非靶标生物毒性两者之间的选择性机理。研究结果将为构建具有不同生物间高度选择性的载药体系提供新线索。

农药微囊的缓控释机理是当前剂型研究的热点之一。深入探讨农药微胶囊在靶标生物界面的沉积、分布、释放规律并加以调控，对于充分发挥其控释优势，实现微囊对靶标生物毒力/毒性的定时、定量调控具有重要价值。本项目利用铁-单宁酸等形成的天然配位化合物组装技术制备不同特征参数的系列微胶囊，研究其在植物叶面的沉积、分布、释放特点及与防治植物病害效果间的量化关系。利用不同的金属离子和有机配体，制备了不同尺度、组装层数、囊壁材料组成、囊壁厚度的吡唑醚菌酯微囊，并进行了基础物化性能表征，考察了其对水稻稻瘟病菌丝生长、孢子萌发的抑制作用，初步明确了药剂的田间防治效果。系统构建和研究了Ca2+-单宁酸包覆型微囊负载体系。考察了以Mg2+、Ca2+、Al3+、Cu2+、Zn2+、Mn2+、Fe3+为中心离子，以单宁酸为有机配体时构建的吡唑醚菌酯微囊负载体系，以及以单宁酸、多巴胺、没食子酸、邻苯二酚、咖啡酸、植酸为有机配体，以Ca2+为中心离子时构建的吡唑醚菌酯微囊负载体系对辣椒炭疽病菌的生物活性。揭示了影响不同剂型吡唑醚菌酯防效的主要因素，不同剂型吡唑醚菌酯通过介导喷雾稀释液的物化性质及与靶标叶片的相互作用，实现黄瓜炭疽病的高效防控。提出了化学农药高效精准施药技术，通过在农药液中添加有效的表面活性剂，控制黄瓜白粉病施药的全过程，提高施药效率。本项目能够为农药高效安全利用提供新线索。