Lavender and Geranium Essential Oil-Loaded Nanogels with Promising Repellent and Antibacterial Effects

Malaria and bacterial infections remain a life-threatening disease with a significant global impact. This study aimed to develop nanogels (NGs) of lavender (Lavandula angustifolia Mill.) and geranium (Pelargonium graveolens L’Hér.) essential oils (EOs) with promising repellent and antibacterial effects. The NGs were formulated using a nanoemulsion-based gel approach; nanoemulsion droplet sizes and zeta potentials were obtained as 146 ± 7 and 106 ± 6 nm and −23.2 ± 0.7 and −17.4 ± 1 mV, respectively. The ATR-FTIR analysis confirmed the successful loading of EOs in NGs. Repellent bioassays conducted on Anopheles stephensi Liston. mosquitoes demonstrated that geranium NG (140 min) was as effective as DEET (140 min), a widely used repellent. Antibacterial tests showed that the nanogels effectively reduced bacterial growth, with the geranium NG exhibiting over 90% reduction against Escherichia coli Migula. The lavender NG displayed higher efficacy against Staphylococcus aureus Rosenbach. These findings highlighted the potential of nanogels containing EOs as promising repellents and antibacterial agents, offering a sustainable and eco-friendly approach for vector control and bacterial infections.