Antibacterial effects of solid lipid nanoparticles gels containing three essential oils

Aim and Background: Excessive use of antibiotics has caused resistance in bacteria. Using higher doses to overcome bacterial resistance causes side effects. The development of novel antibacterial agents using natural substances for example essential oils is required for alternative antibiotics. Among common nanocarriers for efficay improvement of essential oils, solid lipid nanoparticles with higher capacity have been recently more considered. Methods: Solid lipid nanoparticles containing Mentha longifolia, Mentha pulegium, and Zataria multiflora (ZM-SLN) essential oils with a particle size of 103±5, 195±4, and 130±7 nm were first prepared, and they were then transformed to gels. Afterward their antibacterial effects at two concentrations (1.25 and 2.5 mg/mL) against Staphylococcus aureus and Pseudomonas aeruginosa were determined using the ATCC100 method. Results and discussion: Around 88% and 64% growth reduction in standard and clinical strains of P. aeruginosa were observed aſter treatment with ZM-SLN 2.5 mg/mL; its potency was significantly more than other samples (P 0.001). Growth of both standard and clinical strains of S. aureus was fully inhibited aſter treatment with ZM-SLN 1.25 and 2.5 mg/mL; their potency was significantly more than other samples (P 0.001). Conclusion: Solid lipid nanoparticles containing Z. multiflora essential oil with a promising efficacy could be introduced for future preclinical study for determining pharmacokinetics, cytotoxicity, and wound healing properties.