Nanoencapsulation of Artemisia annua Essential Oil in Chitosan-Lipid Carriers Enhances Stability, Larvicidal, Antifungal, and Anticancer Efficacy

Background/Objectives:Artemisia annua essential oil (EO) possesses diverse biological activities; however, its practical application is limited by volatility, instability, and poor bioavailability. This study aimed to develop chitosan-coated nanostructured lipid carriers (CH-NLCs) for efficient encapsulation and delivery of A. annua EO and to evaluate their physicochemical characteristics and biological performance. Methods: The nanoformulation exhibited favorable physicochemical properties, including a high encapsulation efficiency (85.97 ± 1.30%) and a strongly positive surface charge (approximately +45 mV), indicating good colloidal stability. Structural analyses by SEM, FTIR, and XRD confirmed successful encapsulation of the EO within the nanocarrier matrix. Results: The CH-NLC formulation significantly enhanced larvicidal activity against Aedes aegypti larvae, reducing the LC50 value from 213 ppm for the free EO to 142 ppm. Enhanced antifungal activity was also observed, with 47–56% greater inhibition against Malassezia furfur, Trichophyton mentagrophytes, and Candida albicans compared with the free EO. Furthermore, CH-NLC demonstrated improved cytotoxic activity against skin cancer cell lines, achieving IC50 values of 21.4 ± 1.7 µg/mL and 30.1 ± 1.6 µg/mL against A431 and A375 cells, respectively, while maintaining lower toxicity toward normal HaCaT keratinocytes. Mechanistic investigations revealed enhanced apoptosis and an approximately 3-fold increase in intracellular reactive oxygen species (ROS) levels in treated cancer cells. Conclusions: Collectively, these findings indicate that chitosan-coated nanostructured lipid carriers effectively improve the stability and biological efficacy of A. annua essential oil and represent a promising platform for future biomedical and biocidal applications.