Enhanced antimicrobial activity of Cinnamomum zeylanicum essential oil nanoemulsions against Helicobacter pylori: a microfluidic-based assessment

Exploring innovative approaches to combat Helicobacter pylori infections, this study investigates the antimicrobial efficacy of nanoemulsions derived from Cinnamomum zeylanicum (cinnamon) essential oil using an advanced microfluidic platform. Clinical isolates of H. pylori were obtained from gastric biopsies of five patients presenting with gastrointestinal complications at the Shariati Hospital in Tehran. Two nanoemulsion formulations (F₁ and F₂) were developed with distinct particle sizes of 78 nm and 152 nm, respectively, achieved through varying surfactant concentrations. The antibacterial activity was systematically evaluated across multiple parameters, including particle size, concentration gradients (25–300 µg/mL), and residence times (2.5–45 min) within a custom-designed microfluidic device. Bacterial membrane disruption was quantitatively assessed through protein and nucleic acid release measurements, with maximum absorbance values of 1.50 (OD_280nm) and 0.6 (OD_260nm) observed for the F₁ as small size formulation. Scanning electron microscopy revealed significant morphological alterations in bacterial structure upon exposure to the nanoemulsions. Notably, the F₁ formulation (78 nm) demonstrated superior antimicrobial activity, achieving efficacy comparable to 70% ethanol at concentrations of 100 µg/mL within 2.5 min of exposure. This study presents a novel integration of nanotechnology and microfluidics for rapid assessment of natural antimicrobial compounds, offering potential applications in food preservation and therapeutic interventions against H. pylori infections.