Potential of polymer stabilized nano-liposomes to enhance antimicrobial activity of nisin Z against foodborne pathogens

The scientific and industrial interest in antimicrobial nano-carriers has significantly increased in recent years due to post-processing contamination. Liposomes are considered as promising food-grade carrier systems for bioactive-agents. However, due to relatively low stability of liposomes, surface modification or coating is required to improve its efficiency. The purpose of this study was to fabricate chitosan (CA) stabilized nano-liposomes (chitosomes) to enhance the controlled release and antimicrobial effect of nisin-Z against multidrug resistant (MDR) foodbome pathogens. Chitosome characteristics including encapsulation efficiency (EE %), SEM, thermal stability (TGA, DSC), FTIR analysis, antimicrobial potential and in vitro controlled release were investigated. Overall, chitosomes (CS) were thermally more stable, showed higher EE% (86 +/- 1%) as compared to liposomes (56 +/- 2%) and controlled S. aureus, E. faecalis and L. monocytogenes growth better than free or liposomal-nisin. SEM confirmed the size of liposomes from 54 to 108 nm, which increased after coating with chitosan. FTIR analysis revealed the interaction between CA and liposomes by merger of amide I and II peaks. Thus, CA-stabilized liposomes not only improve physico-chemical attributes while ensuring sustained release of nisin but also provide a potential approach to control bacterial contamination in food products for enhanced food safety.