Evaluation of antimicrobial effect of Zataria multiflora essential oil capsulated in chitosan biopolymer compared to free essential oil

Essential oils have many antimicrobial and pharmacological effects, but they are very volatile. The capsulation of drug substances in polymer nanoparticles can improve the therapeutic effects of compounds that are generally volatile. Chitosan is considered as biodegradable biopolymer due to better capsulation, controlled release, and low toxicity in drug delivery. The aim of this study was to investigate the antibacterial activity of Zataria multiflora essential oil capsulated to chitosan- caffeic acid nanogels in comparison to free essential oils. First, nanogel was synthesized by self-cumulative polymerization of chitosan and caffeic acid, and their shape and size were analyzed by spectrophotometric (FTIR) and scanning electron microscopy (SEM), then nanogel was Used for capsulation of Z. multiflora essential oil. Antimicrobial effect of capsulated and free essential oil was studied by disc diffusion and broth microdilution method. The results showed that the capsulated essential oil had a higher bactericidal effect on the bacteria than free essential oil.