Squalane-based emulsion vaccine delivery system: composition with murabutide activate Th1 response

Abstract

Emulsions play an important role in present-day subunit vaccine delivery. Squalane-based emulsion was formulated using surfactants viz., Pluronic F68, Span 85 along with Murabutide (MB) as immunepotentiator. Particle size and zetapotential of the final optimized emulsion was found to be 134 nm and -13 mV, respectively. The in vitro cellular uptake studies performed using fluorescein isothiocyanate (FITC)-labeled ovalbumin (OVA) clearly revealed the rapid uptake of antigen in the presence of emulsion. The in vivo subcutaneous studies involving measurement of OVA-specific IgG antibody titers, Th1/Th2 cytokines were performed and a marked up regulation in IL-2, IL-12 and IFN-γ cytokines indicate Th1 immune response. Results supported that the squalane-based delivery system enhanced the uptake of the antigen by immune cells and elicited humoral as well as cell-mediated immune response in mice. These results indicate the promising application of the new squalane based oil-in-water (O/W) emulsion as capable vaccine delivery system useful for vaccine development.

Evaluating the efficacy of extracted squalene from seed oil in the form of microemulsion for the treatment of COVID‐19: A clinical study

“…38,61 SQ is a safe, effective, and preferred vaccine adjuvant, 37,62 as it improves antigen uptake by immune cells and evokes humoral and cell-mediated immunity. 63 Immune-modulating treatments in severe COVID-19 cases and antioxidant applications are considered as potential treatment strategies. 8,64 The results of this clinical trial suggest that SQ microemulsion administration in severe cases of SARS-CoV-2 infected patients can improve several clinical outcomes.…”

“… 38 , 61 SQ is a safe, effective, and preferred vaccine adjuvant, 37 , 62 as it improves antigen uptake by immune cells and evokes humoral and cell‐mediated immunity. 63 …”

“…In humans and animal trials, intravenous administration of SQ emulsion is safe and well‐tolerated, with a slower clearance from the circulation compared to triglycerides and plant sterols 38,61 . SQ is a safe, effective, and preferred vaccine adjuvant, 37,62 as it improves antigen uptake by immune cells and evokes humoral and cell‐mediated immunity 63 …”

Liposome-polymer complex for drug delivery system and vaccine stabilization

“…These tested adjuvants produced the germinal center reaction with different magnitude through the T follicular helper cells (Tfh) and the results indicated that immunological activity of different adjuvants can be characterized by profiling early immunization biomarkers after primary immunization. Indeed, understanding the modes of action of adjuvant molecules loaded in liposomal derivatives will allow the development of novel vaccination strategies based on a rational design of heterologous prime-boost liposomal nanoformulations [236,237,238,239]. However, the development of novel vaccine delivery systems and adjuvants has been facilitated by nanotechnology resulted in some concern regarding their safety, toxicity, optimal combination of antigens or immunomodulators, and storage conditions are needed to be critically examined in the preclinical stages before clinical use.…”

Plasmodium falciparum Malaria Vaccines and Vaccine Adjuvants

“…Among the emulsion types, O/W type emulsions are highly preferred because of less reactogenicity and sustained release. For example, oleic acid O/W emulsion with monophosphoryl lipid A (MPLA) and squalene-based O/W emulsion with murabutide induce a significant cellular as well as high avidity humoral immune response in mouse models [214,215]. A potent O/W emulsion-based immunological adjuvant, MF59, which is composed of squalene droplets stabilized with Tween 80 and Span 85, elicited higher antibody titers with balanced antibody subclasses than those observed in alum studies.…”