Formulation of selenium nanoparticles encapsulated by alginate-chitosan for controlled delivery of Vibrio Cholerae LPS: A novel delivery system candidate for nanovaccine.

The lipopolysaccharide (LPS) of Vibrio cholerae plays a significant role in stimulating primary protection and immune responses. LPS delivery has been limited by the stimulation of inflammatory cytokines. This work aimed to report the synthesis and performance of this formulation in modulating immune responses and protecting LPS against acidic gastric medium. Alg-Cs-LPS-SeNPs composite was fabricated by an ionic cross-linking/in situ reduction method. Cytokines TNF-α, IL-6, IL-10, and TGF-β were assessed after cells were incubated with different compounds of the system. The main outcomes revealed that encapsulation of LPS-loaded SeNPs in the alginate-chitosan complex was associated with a high entrapment efficiency and could effectively protect LPS against acidic GIT medium. Kinetic profiling revealed that LPS was more slowly released from LPS-loaded Alg-Cs-LPS-SeNPs at pH 1.2, 7.4, and 6.8. These results indicated that Alg-Cs-LPS-SeNPs composite was able to significantly increase anti-inflammatory cytokines and reduce the release of pro-inflammatory cytokines. Thus, these findings show that this system for LPS delivery could be easily biosynthesized and encapsulated for use in the pharmaceutical industry. This study provides proof of the potential for future use of oral LPS vaccines, concomitantly inducing immunomodulatory effects.