Controlled Release of Mosquito-Repellent Essential Oils by Simultaneous Encapsulation into Electrospun Fiber/Dendritic Materials

Global climate change has significantly expanded mosquito habitats, increasing the demand for long-lasting repellents. This study focuses on the controlled-release platform for lavender essential oil (LEO) through its encapsulation into polyvinyl alcohol (PVA) electrospun fibers combined with polyamidoamine (PAMAM) dendrimers. The optimized nanofiber diameters were 320 ± 9 nm for PVA-PAMAM, 345 ± 9 nm for LEO-loaded PVA-PAMAM (PL-PAMAM), and 229 ± 9 nm for DEET-loaded PVA-PAMAM (PD-PAMAM), the latter used as a benchmark synthetic repellent. Mosquito repellency was evaluated using the WHO standard cage test, while odor release was analyzed with an electronic nose (E-nose) and thermogravimetric analysis (TGA). Results demonstrated that the incorporation of PAMAM enabled a sustained release of LEO for up to 28 days, significantly enhancing its repellent performance. PL-PAMAM exhibited 40% greater repellency than LEO-loaded fibers without PAMAM (PL). Similarly, PD-PAMAM showed a 19% improvement over PD, supporting the role of dendrimers in prolonged active release. E-nose data correlated with repellency tests, indicating odor persistence was extended by 60% for LEO and 35% for DEET in dendrimer-containing systems. This study underscores the potential of dendritic-enhanced electrospun fibers for the sustained delivery of natural mosquito repellents.