Antibacterial and antibiofilm activities of chitosan nanoparticles loaded with Ocimum basilicum L. essential oil.

Nanoencapsulation has been verified to be an effective technique to improve the physical stability of essential oils. In this study, Ocimum basilicum L. essential oil (BEO) was encapsulated into chitosan nanoparticles by emulsion and ionic gelation. The success of BEO loading was revealed by Fourier transform infrared (FTIR) spectroscopy, ultraviolet visible spectrophotometry and X-ray diffraction (XRD) analyses. Scanning electron microscopy (SEM) images and dynamic light scattering (DLS) illustrated regular distribution and spherical morphology with a particle size range of 198.7 - 373.4 nm. The prepared samples had an encapsulation efficiency (EE) range of 50.39 - 5.13% and a loading capacity (LC) range of 7.22-19.78%. Encapsulation of BEO into chitosan nanocarriers demonstrated strong antibacterial and antibiofilm capacity against E. coli and S. aureus with inhibition diameter of 15.3 mm and 21.0 mm, respectively, and the obtained nanoparticles were found to damage cell membranes and cause the leakage of biological macromolecules.