Purpose: This study aimed to synthesize geraniol-loaded polymeric nanoparticles (NPs) with enhanced anti-pathogenic properties.
Methods: A rapid nano-precipitation method was used for the preparation of nanoparticles. Geraniol-loaded NPs were characterized for size, encapsulation efficiency (EE), storage stability at different pH (4.0, 7.0, and 10.0) and temperature (4, 25, 37, and 50°C) conditions, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Escherichia coli O157:H7 and Salmonella enterica Typhimurium.
Results: Nanoparticles had a mean EE of 57.5 + 5.5 wt.%. Storage at 25°C or pH 7.0 did not impact NP diameter over 60 days (P > 0.05); > 7 h were required for 50% EO release from NPs stored at 25°C. Antimicrobial NPs inhibited Salmonella Typhimurium and E. coli O157:H7 growth at 0.4 and 0.2 wt%, respectively, whereas MICs of free geraniol against Salmonella and E. coli O157:H7 were 0.8 and 0.4 wt%, respectively. The nanoparticles showed better efficiency at inhibiting growth of Escherichia coli O157:H7 and Salmonella Typhimurium than the efficiency of pure drug (geraniol).
Significance: Nano-encapsulation of hydrophobic antimicrobial could improve their solubility, stabilization, and antimicrobial activity. In addition, hydrophilic nanoparticles are safer and more environmentally friendly than hydrophobic agent since water is used as a solvent rather than acetone, ethanol, etc. Geraniol nanoparticles of lower geraniol concentration were significantly more effective than pure drug in inactivation of both bacteria. Antimicrobial NPs may be useful for the post-harvest decontamination of foods, such as fresh produce, from cross-contaminating microbial pathogens.