Controlled release pesticide formulation with long-term efficacy is highly desirable for improving pesticide utilization and reducing adverse effects. In this study, an environment-friendly controlled release formulation of biological insecticide spinosad was fabricated through the coprecipitation-based synchronous encapsulation with chitosan. The resulted spinosad/chitosan formulation showed an excellent encapsulation efficiency of 60%, obvious pH and temperature sensitivity, and outstanding ultraviolet shielding ability. The in vitro release tests displayed long sustained-release time (> 18 d) and high cumulative release (> 80%) under neutral and weakly alkaline conditions. The primary interaction between spinosad and chitosan has been found to be physical adsorption and adhesion, with the release dynamics following Fickian diffusion mechanism of Ritger-Peppas model. This work contributes to the development of pesticide carrier system of natural polymer materials, with a great potential for insect pest control.

具有长期功效的控释农药制剂对于提高农药利用率和减少不良影响是非常需要的。在这项研究中，通过与壳聚糖的基于共沉淀的同步包封制备了一种环境友好的生物杀虫剂多杀菌素的控释制剂。所得的多杀菌素/壳聚糖制剂显示出优良的60％包封率，明显的pH和温度敏感性以及出色的紫外线屏蔽能力。体外释放测试显示，在中性和弱碱性条件下，持续释放时间长（> 18 d），累积释放率高（> 80％）。发现多杀菌素与壳聚糖之间的主要相互作用是物理吸附和粘附，遵循Ritger-Peppas模型的Fickian扩散机制进行释放。这项工作有助于开发天然高分子材料的农药载体系统，在控制虫害方面具有巨大潜力。