Comparison of chitosan and SLN nano-delivery systems for antibacterial effect of cinnamon (Cinnamomum verum) oil against MDR K pneumoniae and E coli

Abstract

Objectives. Klebsiella pneumoniae and Escherichia coli are among the widespread causes of hospital infections, and their biofilm forming ability causes their resistance to antibiotics. Cinnamon oil (CO) has presented confirmed antimicrobial activity. Solid lipid nanoparticles (SLN) and chitosan nanoparticles are promising carrier systems to increase the stability and therapeutic effects of oils. Methods. This study was designed to develop chitosan nanoparticles containing cinnamon oil (CO–CH) and compare it with cinnamon oil loaded in SLN (CO-SLN). Physicochemical evaluations and antibacterial and anti-biofilm activities were determined. Results. SLN showed a regular morphology and a spherical shape with an average size of 40.65 nm and the CO–CH showed a non-rounded edge with an average size of approximately 116.1 nm. The Encapsulation efficiency of CO–CH and CO–SLN nanoparticles were about 97.5% and 80%, respectively. Results showed 70% cumulative release in CH–CO compared to 40% in CO-SLN in 24 h. Minimum inhibitory concentration (MIC) against E coli and K pneumoniae for CO–CH, CO-SLN and pure CO were 10–15 μg ml−1 , 60 –80 μg ml−1 and 155–175 μg ml−1, respectively. Conclusion. Utilizing nano- systems for the delivery of CO can significantly potentiate its antimicrobial activity. CO–CH revealed a 6-fold higher antibacterial effect compared to CO-SLN and more than 10-fold stronger activity compared to CO.