Abstract

Several life-threatening diseases such as malaria, dengue or zika are transmitted by mosquito bites. Although there are several products available for personal protection against mosquitoes, the adequate efficacy of natural insect repellents (NIR) or the adverse effects of synthetic ones are problems that need to be solved. The encapsulation of NIR in low-cost, nontoxic and biodegradable polymers has emerged as a promising method for the development of eco-friendly repellent systems.

In this work, the encapsulation of citronella oil (CO) into microcapsules of poly (ε-caprolactone) (PCL) was made by electrospraying technique to obtain a system that shows a sustained release of the high volatile oil. Characterizations of the capsules were performed by NMR, FTIR, SEM and DSC techniques. CO encapsulation efficiency (EE) and release studies were also determined by using HPLC technique.

Results demonstrated that a 3/1 PCL-CO ratio and 10 kV were the best conditions to obtain regular and well-formed microcapsules. Characterization techniques showed the presence of CO in the microcapsules with an EE higher than 80%. Release studies in water solution indicated a sustained CO liberation for at least forty days. The present study shows the strong potential of the PCL-CO microcapsules as an effective and sustained release system with potential application in protection against mosquitoes. These microcapsules are not considered microplastics due to their biodegradable character and therefore their use is not restricted by the different legislations.

摘要

疟疾、登革热或寨卡病毒等多种危及生命的疾病是通过蚊虫叮咬传播的。尽管有多种产品可用于个人防蚊，但天然驱虫剂 (NIR) 的足够功效或合成驱虫剂的不利影响是需要解决的问题。将 NIR 封装在低成本、无毒和可生物降解的聚合物中已成为开发环保驱虫系统的有前途的方法。

在这项工作中，通过电喷雾技术将香茅油 (CO) 封装到聚 (ε-己内酯) (PCL) 微胶囊中，以获得显示高挥发油持续释放的系统。胶囊的表征通过 NMR、FTIR、SEM 和 DSC 技术进行。CO 包封效率 (EE) 和释放研究也通过使用 HPLC 技术确定。

结果表明，3/1 PCL-CO 比率和 10 kV 是获得规则和形状良好的微胶囊的最佳条件。表征技术表明，微胶囊中存在 CO，EE 高于 80%。水溶液中的释放研究表明持续释放 CO 至少四十天。目前的研究表明 PCL-CO 微胶囊作为一种有效和持续释放系统的强大潜力，在保护蚊子方面具有潜在的应用价值。由于这些微胶囊具有可生物降解的特性，因此它们不被视为微塑料，因此它们的使用不受不同法规的限制。