Solid Lipid Nanoparticles Loaded with Nisin (SLN-Nisin) are More Effective Than Free Nisin as Antimicrobial, Antibiofilm, and Anticancer Agents

Abstract

Bacteriocins are peptides produced by bacteria to inhibit the growth of other prokaryotes. Nisin is a bacteriocin widely used in the food industry and for biomedical applications. However, bacteriocins have some limitations, as they experience mechanisms of resistance, degradation by proteases, and suboptimal intracellular delivery. Combining bacteriocins with nanoscale drug delivery systems (nano-DDS) is an approach that can help overcome these limitations. Among the nano-DDS, solid lipid nanoparticles (SLN) have been described as promising candidates, because of their potential for industrial scale-up and lower toxicity. The objective of this proof-of-concept study was to investigate the use of nisin-loaded SLN (SLN-Nisin) as an antimicrobial and anticancer therapeutic. We show that SLN-Nisin can significantly inhibit the growth of the oral pathogen, Treponema denticola, disrupt oral biofilms, and decrease oral squamous cell carcinoma cell (OSCC) viability compared to free nisin. Further, analysis with scanning electron microscopy (SEM) revealed significant morphological changes in OSCC cells challenged with SLN-Nisin, compared to the empty-nanoparticle or free nisin, indicating that SLN-Nisin likely decreases cell viability by increasing pore formation. This data reveals that nano-DDS are robust tools that can enhance bacteriocin properties.