Binding to the reference channel was not surprising, as the unmodified CMC surface is negatively charged, and the negative carboxylate groups of the carboxymethylated cellulose resemble the negatively charged sialic acid groups of mucin. to evaluate the effects of hydrophobicity and polar group charge/size around the NE-mucin conversation. Several cationic NE formulations were found to facilitate cellular uptake of the model antigen, ovalbumin (OVA), in a nasal epithelial EGFR-IN-2 cell collection. Furthermore, fluorescent images of tissue sections from mice intranasally immunized with the same NEs made up of green fluorescent protein (GFP) antigen exhibited that these NEs also enhanced Arf6 mucosal layer penetration and cellular uptake of antigenin vivo. NE-mucin interactions observed through biophysical measurements corresponded with the ability of the NE to enhance cellular uptake. Formulations that enhanced antigen uptakein vitroandin vivoalso led to the induction of a more consistent antigen specific immune response in mice immunized with NEs made up of OVA, linking NE-facilitated mucosal layer penetration and cellular uptake to enhancement of the immune response. These findings suggest that biophysical measurement of the mucoadhesive properties of emulsion based vaccines constitutes an effectivein vitrostrategy for selecting NE candidates for further evaluationin vivoas mucosal adjuvants. Keywords:Adjuvant, Intranasal Vaccine, Nanoemulsion, Mucoadhesion, Oil-in-water emulsion == INTRODUCTION == Mucosal vaccination offers unique advantages over parenteral vaccination in the prevention of infectious diseases such as the induction of both mucosal and systemic immunity compared to solely systemic immunity for subcutaneous and intramuscular vaccines.1-5Administration of a vaccine to a mucosal surface can induce immunity at multiple mucosal sites in addition to the application site.3,5,6Nasal immunization, for example, can induce antigen-specific antibody production and a cellular memory response in EGFR-IN-2 the respiratory tract as well as EGFR-IN-2 in the genital tract mucosa.5-7The nasal cavity is a prime site for vaccination as it is easily accessible, has a moderately permeable epithelium with a high availability of immune-reactive sites, and provides minimal exposure to degradative environments.3,8Intranasal (IN) vaccines are currently in development for the prophylaxis of pathogens such asNeisseria meningitidis, respiratory syncytial and herpes simplex type 2 viruses, and are licensed for influenza computer virus.7,9-14As infectious diseases transmitted through mucosal surfaces may be most effectively prevented through mucosal EGFR-IN-2 immunity, development of compounds that are both effective adjuvants and delivery agents for IN antigen administration is usually highly desired. Several adjuvants enhance immune response induction by providing a sustained release of antigen at a specific site through a depot effect.15,16For IN vaccines, the mucous layer presents both a barrier to antigen and adjuvant uptake by the epithelia and dendritic cells (DCs) as well as a site for vaccine deposition. Here we developed bioadhesive nanoemulsion adjuvants for IN administration with the hypothesis that greater mucoadhesion prospects to longer retention EGFR-IN-2 in the nasal mucosa, facilitating antigen-adjuvant permeation across the mucous layer and cellular uptake (Physique 1). Oil-in-water nanoemulsions (NEs) are nanoscale (200700 nm in diameter) droplets composed of a combination of surfactants, a co-solvent (ethanol), oil (soybean oil), and water.17We have shown that as an adjuvant for hepatitis B surface antigen (HBsAg), NEs induce systemic immunity comparable to injected aluminum-based hepatitis vaccines.17Furthermore, they produced mucosal and cellular immune responses not elicited by conventional injectable vaccines, uniquely activated cytokine production by the nasal ciliated epithelium and promoted DC trafficking.18Effective NE adjuvanticity for whole influenza and vaccinia viruses, recombinant anthrax protective antigen, and HIV gp120 have also been demonstrated.19-22 == Physique 1. == Structure of a nanoemulsion (NE) droplet and illustration of NE-mediated antigen delivery through the nasal epithelial layer as facilitated by NE-mucin interactions. (cetylpyridinium chloride.