Nanoemulsion of Lavandula angustifolia Essential Oil/Gold Nanoparticles: Antibacterial Effect against Multidrug-Resistant Wound-Causing Bacteria.

Hospitalized patients are severely impacted by delayed wound healing. Recently, there has been a growing focus on enhancing wound healing using suitable dressings. Lavandula angustifolia essential oil (LEO) showed potential antibacterial, anti-inflammatory, and wound healing properties. However, the prepared gold nanoparticles possessed multifunctional properties. Consequently, the present investigation aimed to synthesize a novel nanosystem consisting of nano- Lavandula angustifolia essential oil and gold nanoparticles prepared through ultrasonic nanoemulsifying techniques in order to promote wound healing and combat bacterial infection. LEO showed potent antibacterial activity against Klebsiella pneumoniae , MRSA and Staphylococcus aureus with minimum inhibitory concentration (MIC) values of 32, 16 and 16 µg/mL, respectively, while exhibiting low activity against Proteus mirabilis . Interestingly, the newly formulated nano-gold/nano- Lavandula angustifolia penetrated the preformed P. mirabilis biofilm with a full eradication of the microbial cells, with MIC and MBEC (minimal biofilm eradication concentration) values reaching 8 and 16 µg/mL, respectively. The cytotoxic effect of the novel nanoformula was also assessed against WI-38 fibroblasts vero (normal) cells (IC 50 = 0.089 mg/mL) while nano-gold and nano- Lavandula angustifolia showed higher results (IC 50 = 0.529, and 0.209 mg/mL, respectively). Nano-gold/nano- Lavandula angustifolia formula possessed a powerful wound healing efficacy with a 96.78% wound closure. These findings revealed that nano-gold/nano- Lavandula angustifolia nanoemulsion can inhibit bacterial growth and accelerate the wound healing rate.