两亲性海藻酸衍生物与糖基表面活性剂稳定载药乳液的构建及靶标表面行为

The aim of this project is to develop some environmentally friendly and high efficiency pesticide drug-loaded oil-in-water(O/W) emulsions stabilized by synergistic effects of green surfactants. The emulsion is mainly made up of one natural macromolecular derivatives surfactant and one small molecular green sugar surfactant. And the natural macromolecular surfactant is grafted sodium alginate derivatives prepared by our own laboratory. This research is promising and will benefit to keep the agrochemicals sustainable development with important scientific and practical significance. Firstly, three kinds of sodium alginates with different relative molecular mass will be obtained from Sargassum algae in HaiNan coastal waters by extraction, oxidative degradation and precipitation. Cholesterol will be covalently coupled to sodium alginate to get grafted derivatives in an aqueous-phase reaction via N,N-dicyclohexylcarbodiimide as a coupling agent and 4-(N,N-dimethylamino)pyridine as a catalyst at room temperature. Then, the interaction between amphiphilic cholesteryl grafted sodium alginate derivatives and sugar surfactants will be studied in their mixed system. The effects of the mixed system on stability of bifenthrin-loaded emulsion will be investigated also.Based on these studies, the mechanism of this O/W emulsion stabilized by synergistic effects of this mixed system will be elucidated. Furthermore, the behavior patterns of bifenthrin-loaded emulsion on hydrophobic target--the surface of paraffin wax or the leaf of banana--will be investigated in order to improve its bioavailability efficiency. The effects of this mixed surfactant system on the wettability of the emulsion on the target surface will be discovered. The optimized formulation of the bifenthrin-loaded emulsion will be found according to all of these results.

利用合成天然高分子衍生物表面活性剂与绿色糖基表面活性剂的协同效应 ，构建稳定高效、与环境友好的载有农药药物的O/W型乳液，有利于促进农药工业可持续发展，项目具有重要的科学及现实意义。本项目从海南马尾藻提取分离及氧化降解制备3种不同分子量范围的海藻酸钠，采用胆固醇接枝改性海藻酸钠，合成两亲性胆固醇基海藻酸衍生物。以高效氯氟氰菊酯为模型药物，研究不同分子量两亲性海藻酸衍生物与糖基表面活性剂的相互作用及该复合体系对形成载药O/W乳液的稳定性的影响，揭示两者协同效应对载药O/W乳液的稳定性机制。为提高载药乳液的生物利用度，研究乳液在疏水性靶标（石蜡、香蕉叶片）表面行为，找到两亲性海藻酸衍生物与糖基表面活性剂复合体系对药液在靶标表面的润湿性能的影响规律，调控及优化乳液组成，为构建一种新的高效农药药物载体及传递途径提供科学依据。

利用合成天然高分子衍生物表面活性剂与绿色糖基表面活性剂的协同效应 ，构建稳定高效、与环境友好的载有农药药物的O/W型乳液，有利于促进农药工业可持续发展。本项目从海南马尾藻提取分离及氧化降解制备不同分子量的海藻酸钠，以DCC/DMAP 偶联反应将胆固醇基接枝到海藻酸钠上，制备了3种胆固醇基接枝海藻酸钠衍生物（HMW-CSAD，Mw=112,230；MMW-CSAD，Mw=64,490；LMW-CSAD，Mw=47,748）。通过FTIR、1HNMR、荧光光谱、动态光散射、TEM 和释药实验分别对改性海藻酸钠的结构和聚集行为进行了表征，其在水溶液中临界聚集浓度分别为0.5995g/L、0.4786g/L、0.4145g/L，表明这3种高分子表面活性剂均具有良好的表面活性。以高效氯氟氰菊酯为模型药物，从静置稳定性、离心稳定性、分散稳定性、冻融稳定性、液滴粒径、Zeta电位、黏度等方面，研究了不同分子量胆固醇接枝改性的海藻酸钠衍生物(CSAD)与烷基糖苷(APG)形成的高效氯氟氰菊酯O/W乳液物化性质的影响，发现两者协同效应对载药O/W乳液的稳定性机制主要是：通过两亲性CSAD与APG自组装形成复合胶束，在油水界面形成黏弹性界面膜，阻止液滴聚结，获得了具有高稳定性的载有农药药物氯氟氰菊酯的O/W乳液；为提高载药乳液的生物利用度，通过测定药液的动、静态表面张力、接触角以及在香蕉叶片上的持留量和药物吸附量，考察了CSAD对载药水乳液在叶片上的润湿性和沉积量的影响，发现通过两亲性聚合物CSAD的疏水作用与APG形成的混合胶束，可有效地提高药液在靶标叶片上的持留量和吸附量，从而构建了一种新的高效农药药物载体。本项目已发表论文18篇，其中SCI收录13篇，EI收录3篇，核心期刊2篇，获得授权专利5篇，与课题组其它相关成果结合，获得2016年度海南省科技进步奖三等奖一项。培养硕士研究生7名。