Synthesis and antimicrobial evaluation of chitosan nanoparticles containing Echium amoenum

Abstract

Background and purpose: Due to constant contact with the outside environment, the mouth is always a place for accumulation of pathogenic and opportunistic microorganisms. With the increase of resistance caused by the excessive use of synthetic antibiotics, it seems necessary to find alternative drugs that have both antibacterial properties and the least side effects for humans. The use of medicinal plants such as the Echium amoenum with high bioactivity properties can be an alternative to antibiotics. One of the biocompatible and bioactive carriers for the delivery of drugs is chitosan nanoparticles, which help in the transfer and slow release of antimicrobial substances. Therefore, the aim of this study is to load the extract of the borage plant on chitosan nanoparticles and investigate the antimicrobial effects of this compound against Streptococcus mutans, Candida albicans and Escherichia coli. Materials and method: Chitosan solution was prepared in 1% acetic acid. Then tripolyphosphate solution was added to it. The mixture was centrifuged and the resulting powder was dried. The Echium amoenum extract was prepared and added to the chitosan powder. After stirring, it was centrifuged and the powder of chitosan nanoparticles containing Echium amoenum was separated and dried. The properties and characteristics of nanoparticles were evaluated by Dynamic Light Scattering (DLS) test and its stability by examining zeta potential. Finally, the antimicrobial effects of this compound on Streptococcus mutans, Escherichia coli and Candida albicans was evaluated by evaluating (minimum inhibitory concentration) (MIC) and minimum bactericidal concentration (MBC) through the Microdilution method. Results: The size of chitosan nanoparticles and chitosan containing extract were 98 ± 1.24 and 108 ± 1.54 nm, respectively, and their zeta potential was +17 and +10. MIC concentration for chitosan, chitosan extract and nanoparticles containing extract for Escherichia coli was 170.67, 666.67 and 341.34 mg/ml respectively and for Streptococcus mutans was 106.67, 416.67 and 67 respectively 170/mg/ml and for Candida albicans was 426.67, 1000 and 341.34 mg/ml respectively. MBC concentration for chitosan, chitosan extract and chitosan nanoparticles containing extract for Escherichia coli was 426.67, 1666.67 and 853.34 mg/ml respectively and for Streptococcus mutans was 426.67, 833.34 and 67 respectively 426/mg/ml and for Candida albicans was 34/853, 1666/67 and 853/34 mg/ml respectively. Conclusion: The loading of Echium amoenum extract into chitosan nanoparticles creates a stable compound and improves its antibacterial properties against Streptococcus mutans and Escherichia coli and antifungal properties against Candida albicans. Echium amoenum extract loaded in chitosan nanoparticles can be used as an antibacterial bioactive compound against oral infections