Preparation and Evaluation of Chitosan Nanoparticles containing Iranian Eschium Amoenum Extract and its Antimicrobial Effects on Common Oral Microorganisms

Chitosan nanoparticles are one of the biocompatible and bioactive vectors in medicine contributing to the transfer and slow release of antimicrobial agents. The present study investigated loading Echium amoenum extract on chitosan nanoparticles and evaluated the antimicrobial effects of this composite on Streptococcus mutans, Candida albicans, and Escherichia coli.

First, a chitosan solution was prepared in 1% acetic acid. Then, a tripolyphosphate (TPP) solution was added to it. The resulting mixture was centrifuged, and finally, its powder was dried. The E. amoenum extract was prepared and added to the chitosan powder. After mixing, the mixture was centrifuged, and the chitosan nanoparticle powder containing E. amoenum was separated and dried. The properties and characteristics of the nanoparticles were determined by the DLS test, and their stability was evaluated using the zeta potential. Finally, the antimicrobial effect of this product was evaluated on S. mutans, E. coli, and C. albicans using MIC and MBC through the microdilution method.

The sizes of chitosan nanoparticles and chitosan nanoparticles containing the plant extract were 98±1.24 and 108±1.54 nm and their zeta potentials were +17 and +10, respectively. The MIC for chitosan, the extract, and chitosan nanoparticles containing E. amoenum extract for E. coli were 170.67, 666.67, and 341.34 mg/mL; these values for S. mutans were 106.67, 416.67, and 170.67 mg/mL, with 426.67, 1000, and 341.34 mg/mL for C. albicans, respectively. The MBC for chitosan, the extract, and chitosan nanoparticles containing E. amoenum extract for E. coli were 426.67, 1666.67, and 853.34 mg/mL; these values for S. mutans were 426.67, 833.34, and 426.67 mg/mL, with 853.34, 1666.67, and 853.34 mg/mL for C. albicans, respectively.

Chitosan nanoparticles are an efficient vector for E. amoenum extract and loaded chitosan nanoparticles can be used as a bioactive antibacterial agent against various oral microorganisms.