Elenice Francisco da Silva

Lipid nanoparticles (LNPs) are versatile delivery systems with high interest because they allow the release of hydrophobic and hydrophilic molecules, such as essential oils (EOs) and plant extracts. This review covers published works between 2019 and 2024 that have reported the use of essential EO-based LNPs with antimicrobial properties and applications in human and animal health, as well as biopesticides. In the human healthcare field, reports have addressed the effect of encapsulating EOs in lipid nanosystems with antiviral, antibacterial, antiprotozoal and antifungal activities. In animal care, this still needs to be more deeply explored while looking for more sustainable alternatives against different types of parasites that affect animal health. Overall, the antibacterial activities of LNPs carrying EOs are described as alternatives to the use of synthetic antibiotics. In the field of agriculture, studies showed that these approaches in the control of phytopathogens and other pests that affect food production. There is a growing demand for innovative and more sustainable technologies. However, there are still some challenges to be overcome in order to allow these innovations to reach the market.

Campylobacter is a virulent Gram-negative bacterial genus mainly found in the intestines of poultry. The indiscriminate use of traditional antibiotics has led to drug resistance in these pathogens, necessitating the development of more efficient and less toxic therapies. Despite their complex biologically active structures, the clinical applications of essential oils (EOs) remain limited. Therefore, this study aimed to increase the bioavailability, stability, and biocompatibility and decrease the photodegradation and toxicity of EO using nanotechnology. The diffusion disk test revealed the potent anti-Campylobacter activity of cinnamon, lemongrass, clove, geranium, and oregano EOs (>50 mm). These were subsequently used to prepare nanostructured lipid carriers (NLCs). Formulations containing these EOs inhibited Campylobacter spp. growth at low concentrations (0.2 mg/mL). The particle size, polydispersity index, and zeta potential of these systems were monitored, confirming its physicochemical stability for 210 days at 25 °C. FTIR-ATR and DSC analyses confirmed excellent miscibility among the excipients, and FE-SEM elucidated a spherical shape with well-delimited contours of nanoparticles. The best NLCs were tested regarding nanotoxicity in a chicken embryo model. These results indicate that the NLC-based geranium EO is the most promising and safe system for the control and treatment of multidrug-resistant strains of Campylobacter spp.