The Key Laboratory of Resource Chemistry of Ministry of Education, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, PR China.
Colloids Surf B Biointerfaces. 2013 Feb 1;102:341-7. doi: 10.1016/j.colsurfb.2012.07.043. Epub 2012 Aug 14.
Cyanobacteria (Cyb), an environment waste, was first utilized as a carrier for controlled release of avermectin (Av) and improvement of pesticide photostability. Microalgae powder prepared from Cyb blooms was characterized by elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), optical microscopy, and scanning electron microscopy (SEM). The globular morphology and the size (~3.5μm) of Cyb do not change significantly, with increase of roughness, after Av adsorption and Carbopol coating. Av manifests considerable binding affinity to Cyb in isopropanol and adsorption decreases in more polar solvents at 25°C. An extended release of Av from Cyb-Av in ethanol/water (v/v, 4:1) mixture was obtained and the release was further controlled by the Carbopol resin coated on Cyb-Av. Thicker Carbopol coating results in larger lag time (t(0)), slower release rate, and less total release amount. The release process was found to be controlled by a diffusion mechanism, but was strongly affected by polymer matrix-Av interaction and polymer relaxation. Finally, adsorbed Av on Cyb exhibits much greater UV-stability than free Av.
蓝藻 (Cyb) 是一种环境废物，最初被用作阿维菌素 (Av) 的控释载体和提高农药光稳定性。从 Cyb 水华制备的微藻粉末通过元素分析 (EA)、X 射线光电子能谱 (XPS)、红外光谱 (IR)、光学显微镜和扫描电子显微镜 (SEM) 进行了表征。Av 吸附和 Carbopol 涂层后，Cyb 的球形形态和尺寸 (~3.5μm) 没有明显变化，但粗糙度增加。Av 在异丙醇中与 Cyb 表现出相当大的结合亲和力，而在 25°C 下在更极性的溶剂中吸附减少。从 Cyb-Av 在乙醇/水 (v/v，4:1) 混合物中的释放可以得到 Av 的延长释放，并且通过涂覆在 Cyb-Av 上的 Carbopol 树脂进一步控制释放。较厚的 Carbopol 涂层导致更长的滞后时间 (t(0))、较慢的释放速率和更少的总释放量。释放过程被发现是由扩散机制控制的，但受到聚合物基质-Av 相互作用和聚合物松弛的强烈影响。最后，Cyb 上吸附的 Av 比游离的 Av 具有更高的 UV 稳定性。
